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ZIP Code Destiny

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    Chapter 2.2 · The first year · Report

    Infant mortality

    Infant mortality in 2018 to 2022 ran from 3.7 deaths per 1,000 live births in Massachusetts and New Hampshire to 8.7 in Mississippi.

    Every estimate of the chapter with its interval and every figure as a table, generated from the chapter's data files. Table n of this report is figure n of the chapter. The same report as Markdown: report.md.

    Identification

    Title
    Infant mortality
    Label
    The first year
    Chapter
    2.2 (Part II, Birth; An American life)
    Question
    How does the infant mortality rate vary across states and levels of county deprivation, and how does it differ by race and by age at death?
    Dek
    Infant mortality in 2018 to 2022 ran from 3.7 deaths per 1,000 live births in Massachusetts and New Hampshire to 8.7 in Mississippi.
    Grain
    counties
    Status
    published
    Published
    Updated
    not revised
    Data sources
    • CDC WONDER linked birth and infant death. CDC WONDER linked birth and infant death, state totals and race, county totals and age at death, 2018 to 2022 (mother's race 2018 and 2019 only); years: 2018-2022; weights: none (full counts; crude rates)
    • Area Deprivation Index. Neighborhood Atlas Area Deprivation Index 2023 (v4.0.1), tract national rank, averaged to counties with 2019-2023 tract population; years: 2023 release (version 4.0.1; built on ACS 2019-2023); weights: 2019-2023 tract population
    • County Health Rankings. County Health Rankings 2024, infant mortality (infant deaths per 1,000 live births, 2015 to 2021), counties with at least 20 infant deaths; years: 2024 release; weights: births (County Health Rankings denominator)
    Canonical URL
    https://vishalsingh.org/zipcode/infant-mortality
    Markdown
    https://vishalsingh.org/zipcode/infant-mortality/report.md
    BibTeX
    @misc{singh2026infantmortality,
      author = {Singh, Vishal},
      title = {Infant mortality},
      year = {2026},
      url = {https://vishalsingh.org/zipcode/infant-mortality},
      note = {In ZIP Code Destiny. Published 9 October 2026.}
    }

    Principal estimates

    The facts the dek and the opening prose cite, in order of appearance. Every fact is in the table of all estimates below.

    EstimandPopulationPeriodValueIntervalnWeightsSourceFact id
    crude rate from the death count, normal intervallive births in Massachusetts2018 to 20223.795% CI 3.5 to 3.91,260 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant deathimr_state_low
    the denominator of an infant mortality rate (a definition)all live birthsall years (a definition)1,000none (definition)CDC WONDER linked birth and infant deathper_1000
    crude rate from the death count, normal intervallive births in Mississippi2018 to 20228.795% CI 8.3 to 9.21,564 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant deathimr_state_high
    crude rate from the death count, normal intervallive births in the 50 states and DC2018 to 20225.595% CI 5.5 to 5.6102,503 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant deathimr_natl
    count of countiesnamed counties with a published death count in every year 2018 to 2022infant deaths and live births in 2018 to 2022240none (full count)CDC WONDER linked birth and infant deathcounties_used
    births-weighted mean of county rates (the pooled rate), bootstrap interval over countieslive births in the least deprived quarter of the counties used, by county deprivation rank2018 to 20223.995% CI 3.7 to 4.160 countiesbirths in each countyCDC WONDER linked birth and infant deathimr_q1
    births-weighted mean of county rates (the pooled rate), bootstrap interval over countieslive births in the most deprived quarter of the counties used, by county deprivation rank2018 to 20227.295% CI 6.7 to 7.660 countiesbirths in each countyCDC WONDER linked birth and infant deathimr_q4
    crude rate from state counts, normal intervallive births to Black mothers (single race, any ethnicity) in the United States, states with a published count2018 and 201910.395% CI 10.1 to 10.512,953 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant deathimr_black
    crude rate from state counts, normal intervallive births to white mothers (single race, any ethnicity) in the United States, states with a published count2018 and 20194.795% CI 4.7 to 4.826,516 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant deathimr_white

    Findings

    Infant mortality in 2018 to 2022 was 8.78.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 8.3 to 9.2n1,564 infant deathsWeightsnone (crude rate from counts)Populationlive births in MississippiPeriod2018 to 2022SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death live births in Mississippi and 3.73.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 3.5 to 3.9n1,260 infant deathsWeightsnone (crude rate from counts)Populationlive births in MassachusettsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in Massachusetts and New Hampshire, against 5.55.5 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.5 to 5.6n102,503 infant deathsWeightsnone (crude rate from counts)Populationlive births in the 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death for the United States. Among the 240240 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties with a published death count in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death large counties that publish a death count in every year, the rate rises from 3.93.9 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countiesInterval95% CI 3.7 to 4.1n60 countiesWeightsbirths in each countyPopulationlive births in the least deprived quarter of the counties used, by county deprivation rankPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in the least deprived quarter of counties to 7.27.2 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countiesInterval95% CI 6.7 to 7.6n60 countiesWeightsbirths in each countyPopulationlive births in the most deprived quarter of the counties used, by county deprivation rankPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in the most deprived. Requiring a count in every year leaves out the counties whose deaths are withheld in any year. In 2018 and 2019, the only years for which the linked birth and infant death file reports the mother's race, the rate was 10.310.3 infant deaths per 1,000 live birthsEstimandcrude rate from state counts, normal intervalInterval95% CI 10.1 to 10.5n12,953 infant deathsWeightsnone (crude rate from counts)Populationlive births to Black mothers (single race, any ethnicity) in the United States, states with a published countPeriod2018 and 2019SourceCDC WONDER linked birth and infant death for infants of Black mothers and 4.74.7 infant deaths per 1,000 live birthsEstimandcrude rate from state counts, normal intervalInterval95% CI 4.7 to 4.8n26,516 infant deathsWeightsnone (crude rate from counts)Populationlive births to white mothers (single race, any ethnicity) in the United States, states with a published countPeriod2018 and 2019SourceCDC WONDER linked birth and infant death for infants of white mothers.

    These are rates for states, counties and groups of births. They describe where and among whom infants died and say nothing about why a particular infant did. The conditions that come before many infant deaths, low birthweight and preterm birth, are in Chapter 2.1, Birthweight and preterm birth, which also shows infant mortality for Black and white mothers by county deprivation. The fall in the number of births is in Chapter 2.4, Where births are falling.

    What the rate counts and where the numbers come from

    An infant death is the death of a baby before its first birthday. The infant mortality rateInfant mortality rateThe number of babies who die before their first birthday for every thousand live births. divides such deaths by live births and is reported here as deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death. It is a crude rateCrude rateDeaths or births divided by the population, with no adjustment for age. A place with older residents has a higher crude death rate even if health at each age is the same., with no adjustment for the age or health of mothers. Researchers also split infant deaths by age. Neonatal deaths occur before 2828 days of ageEstimandage below which an infant death is neonatal; from this age to the first birthday it is postneonatal (a definition)Weightsnone (definition)PopulationinfantsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death days of age, and postneonatal deaths occur from that age to the first birthday. A comparison of the United States with European countries found that the American disadvantage is concentrated in the postneonatal period and among infants of lower socioeconomic status.[1]

    The numbers come from the linked birth and infant death records on CDC WONDER, which match each infant death certificate to the infant's birth certificate.[2] State files cover all 5151 jurisdictionsEstimandcount of states and DC in the state filesWeightsnone (full count)Populationthe 50 states and the District of ColumbiaPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death jurisdictions, and WONDER publishes every state total in full. They record 102,503102,503 infant deathsEstimandcount of infant deaths (WONDER weights deaths, so the count can differ from the unweighted number of records by rounding)Weightsnone (full count)Populationinfants born in the 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death infant deaths among 18.5 million18.5 million live birthsEstimandcount of live birthsn18,484,949 birthsWeightsnone (full count)Populationlive births in the 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death live births in 2018 to 2022. County files name only counties of 250,000250,000 residentsEstimandpopulation size at which WONDER names a county in the linked file (a definition)Weightsnone (definition)Populationcounties that CDC WONDER linked birth and infant death names individuallyPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death residents or more, pool every other county in a state into one row, and withhold any county cell with fewer than 1010 infant deathsEstimanda cell with fewer deaths than this is withheld (a definition)Weightsnone (definition)Populationcells of the WONDER linked birth and infant death filesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death deaths. A withheldSuppressionThe withholding of a number because the count behind it is too small to publish without risking the identification of a person. A suppressed value is missing, not zero. cell is missing, not zero, and nothing in this chapter is derived from a total minus the cells that are published. The state file for 2021 gives a national rate of 5.445.44 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.36 to 5.51n19,927 infant deathsWeightsnone (crude rate from counts)Populationlive births in the 50 states and DCPeriod2021SourceCDC WONDER linked birth and infant death, which is the rate NCHS reports for that year.[2]

    WONDER weights infant deaths in the linked file, so a count can differ from the number of death records, and the age groups from a total, by rounding.

    State rates vary widely and most of the highest are in the South

    Mississippi has the highest state rate, 8.7 (95% CI 8.3 to 9.2)8.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 8.3 to 9.2n1,564 infant deathsWeightsnone (crude rate from counts)Populationlive births in MississippiPeriod2018 to 2022SourceCDC WONDER linked birth and infant death. Massachusetts, at 3.7 (95% CI 3.5 to 3.9)3.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 3.5 to 3.9n1,260 infant deathsWeightsnone (crude rate from counts)Populationlive births in MassachusettsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death, and New Hampshire, at 3.7 (95% CI 3.2 to 4.2)3.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 3.2 to 4.2n224 infant deathsWeightsnone (crude rate from counts)Populationlive births in New HampshirePeriod2018 to 2022SourceCDC WONDER linked birth and infant death, have the lowest rates, and their intervals overlap. The ratio of the rate in Mississippi to the rate in Massachusetts is 2.4 (95% CI 2.2 to 2.6)2.4 ratio of ratesEstimandratio of Mississippi's crude rate to Massachusetts's, log-normal interval on the two death countsInterval95% CI 2.2 to 2.6n2,824 infant deathsWeightsnone (crude rates from counts)Populationlive births in Mississippi and in MassachusettsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death (Table 1). Arkansas, Louisiana and Alabama follow Mississippi.

    The Census South region holds 77 statesEstimandhighest-rate states in the Census South region (16 states and DC)n10 statesWeightsnone (each state counts once)Populationthe ten states with the highest infant mortality ratesPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of the 1010 statesEstimandthe number of highest-rate states examined (a definition)Weightsnone (definition)Populationthe 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death states with the highest rates and 1717 jurisdictionsEstimandjurisdictions in the Census South region (16 states and DC)Weightsnone (full count)Populationthe 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of the 5151 jurisdictionsEstimandcount of states and DC in the state filesWeightsnone (full count)Populationthe 50 states and the District of ColumbiaPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death jurisdictions. The remaining states in that group are Ohio, South Dakota and Indiana.

    Pooled over births, the rate in the South is 6.3 (95% CI 5.9 to 6.9)6.3 infant deaths per 1,000 live birthsEstimandpooled crude rate over the states of the group (17 states), bootstrap interval over those statesInterval95% CI 5.9 to 6.9n17 statesWeightsbirths in each statePopulationlive births in the Census South region (16 states and DC)Period2018 to 2022SourceCDC WONDER linked birth and infant death against 5.1 (95% CI 4.6 to 5.7)5.1 infant deaths per 1,000 live birthsEstimandpooled crude rate over the states of the group (34 states), bootstrap interval over those statesInterval95% CI 4.6 to 5.7n34 statesWeightsbirths in each statePopulationlive births outside the Census South regionPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in the rest of the country, a ratio of 1.2 (95% CI 1.1 to 1.4)1.2 ratio of ratesEstimandratio of pooled crude rates (17 South states over 34 other states), stratified bootstrap interval that resamples the states of each group separatelyInterval95% CI 1.1 to 1.4n51 states in the two groupsWeightsbirths in each statePopulationlive births in the 50 states and DC, Census South region over the restPeriod2018 to 2022SourceCDC WONDER linked birth and infant death. Within the rest, the Midwest has 6.1 (95% CI 5.5 to 6.5)6.1 infant deaths per 1,000 live birthsEstimandpooled crude rate over the region's states (12 states), bootstrap interval over those statesInterval95% CI 5.5 to 6.5n12 statesWeightsbirths in each statePopulationlive births in the Midwest Census regionPeriod2018 to 2022SourceCDC WONDER linked birth and infant death, close to the South, while the Northeast has 4.5 (95% CI 3.9 to 5.2)4.5 infant deaths per 1,000 live birthsEstimandpooled crude rate over the region's states (9 states), bootstrap interval over those statesInterval95% CI 3.9 to 5.2n9 statesWeightsbirths in each statePopulationlive births in the Northeast Census regionPeriod2018 to 2022SourceCDC WONDER linked birth and infant death and the West 4.6 (95% CI 4.3 to 5.3)4.6 infant deaths per 1,000 live birthsEstimandpooled crude rate over the region's states (13 states), bootstrap interval over those statesInterval95% CI 4.3 to 5.3n13 statesWeightsbirths in each statePopulationlive births in the West Census regionPeriod2018 to 2022SourceCDC WONDER linked birth and infant death. Intervals resample whole states.

    Of the 5151 jurisdictionsEstimandcount of states and DC in the state filesWeightsnone (full count)Populationthe 50 states and the District of ColumbiaPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death jurisdictions, 2121 statesEstimandstates whose 95% interval lies above the national raten51 jurisdictionsWeightsnone (crude rates from counts)Populationthe 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death have an interval entirely above the national rate and 1616 statesEstimandstates whose 95% interval lies below the national raten51 jurisdictionsWeightsnone (crude rates from counts)Populationthe 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death have one entirely below it. The others cannot be told apart from the national rate on these counts. The pooled period includes the pandemic years, but no single year sets the pooled rates. The national rate was lowest in 2020, at 5.45.4 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.3 to 5.5n19,576 infant deathsWeightsnone (crude rate from counts)Populationlive births in the 50 states and DCPeriod2020SourceCDC WONDER linked birth and infant death, and highest in 2018, at 5.75.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.6 to 5.7n21,496 infant deathsWeightsnone (crude rate from counts)Populationlive births in the 50 states and DCPeriod2018SourceCDC WONDER linked birth and infant death.

    Counties with high rates are concentrated in the South

    WONDER names only 261261 countiesEstimandcount of counties (two identifiers with no births are left out)Weightsnone (full count)Populationcounties that WONDER linked birth and infant death names individually and that have birthsPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death counties in its linked file, which is too few to map infant mortality. County Health Rankings, from the same NCHS vital statistics, publishes a rate for every county with at least 2020 infant deathsEstimandfewest infant deaths in the period for which County Health Rankings publishes a county rate, which is also the book's map floor (a definition)Weightsnone (definition)Populationcounties on the mapPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings infant deaths in the period. It gives 1,2061,206 countiesEstimandcount of counties with at least 20 infant deaths in the periodWeightsnone (full count)Populationcounties and county equivalents with a County Health Rankings infant mortality rate and an ADIPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings counties a rate for infant deaths and live births in 2015 to 2021 (Table 2). That period is not WONDER's, so the two sources are compared before the map is used. Across the 240240 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties with a published death count in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death large counties that both cover, the two sets of county rates correlate at 0.980 (95% CI 0.974 to 0.985)0.980 correlation coefficientEstimandbirths-weighted correlation between the county rate in WONDER and in County Health Rankings, county-cluster bootstrap intervalInterval95% CI 0.974 to 0.985n240 countiesWeightsWONDER births in each countyPopulationlive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022PeriodWONDER 2018 to 2022 and County Health Rankings 2015 to 2021SourceCounty Health Rankings.

    Of the mapped counties in the highest tenth of rates, 85.1%85.1% percent of countiesEstimandshare of those counties in the Census South region (16 states and DC)n121 countiesWeightsnone (each county counts once)Populationmapped counties in the highest tenth of infant mortality ratesPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings are in the South, which holds 49.3%49.3% percent of countiesEstimandshare of mapped counties in the Census South region (16 states and DC)n1,206 countiesWeightsnone (each county counts once)Populationall mapped countiesPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings of the mapped counties. Mississippi holds 2525 countiesEstimandcount of those counties in Mississippin121 countiesWeightsnone (each county counts once)Populationmapped counties in the highest tenth of infant mortality ratesPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings of those counties, more than any other state. The 1,9371,937 countiesEstimandcount of counties with no County Health Rankings rateWeightsnone (full count)Populationcounties and county equivalents on the map (50 states and DC)Periodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings gray counties had fewer than 2020 infant deathsEstimandfewest infant deaths in the period for which County Health Rankings publishes a county rate, which is also the book's map floor (a definition)Weightsnone (definition)Populationcounties on the mapPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings infant deaths in the period, which in practice means small counties. Gray is not zero, and the tooltip gives the reason. The key runs from 3.73.7 infant deaths per 1,000 live birthsEstimandfifth percentile of the mapped county rates, the low end of the map key (counties beyond it take the end color)n1,206 countiesWeightsnone (each county counts once)Populationmapped countiesPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings to 10.610.6 infant deaths per 1,000 live birthsEstimandninety-fifth percentile of the mapped county rates, the high end of the map key (counties beyond it take the end color)n1,206 countiesWeightsnone (each county counts once)Populationmapped countiesPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, the fifth to ninety-fifth percentile of the mapped county rates, and the end colors include the counties beyond those limits. The highest county rates rest on few deaths, so a single county's rate is imprecise and the pattern across many counties is what the map shows.

    Infant mortality rises with county deprivation

    To place counties on one scale, each census tract carries its Area Deprivation IndexArea Deprivation Index (ADI)A score that ranks neighborhoods by income, education, employment and housing conditions drawn from the American Community Survey. In this book a higher national percentile means a more deprived neighborhood. national rank, which orders neighborhoods by deprivation with a higher rank meaning more deprived.[3] A county's rank is the average of its tracts' ranks weighted by population, the same measure used in Chapter 2.1, Birthweight and preterm birth. That chapter cuts its quartiles within the larger set of counties that WONDER natality names, and the quartiles here are cut within the counties used below. The quartile edges differ, so quartile rates in the two chapters are not directly comparable. The gradient uses the 240240 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties with a published death count in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death of the 261261 countiesEstimandcount of counties (two identifiers with no births are left out)Weightsnone (full count)Populationcounties that WONDER linked birth and infant death names individually and that have birthsPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death named counties that publish a death count in every year from 2018 to 2022. They hold 62.3%62.3% percent of live births in the United StatesEstimandshare of births in the counties usedn18,484,949 birthsWeightsnone (full count)Populationlive births in the 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of births in the United States. The quarters here are quarters of these large counties, so the most deprived quarter is relative to large counties and not to the nation.

    Their ranks run from 33 national percentile rank (1 least deprived, 100 most)Estimandlowest county deprivation rank among the counties usedn240 countiesWeights2019-2023 tract populationPopulationthe counties usedPeriod2019-2023 tract population weightsSourceArea Deprivation Index to 8484 national percentile rank (1 least deprived, 100 most)Estimandhighest county deprivation rank among the counties usedn240 countiesWeights2019-2023 tract populationPopulationthe counties usedPeriod2019-2023 tract population weightsSourceArea Deprivation Index, while 712712 countiesEstimandcount of counties whose rank is above the highest rank among the counties usedn3,128 countiesWeightsnone (full count)Populationcounties and county equivalents in the 50 states and DC with a deprivation rankPeriod2019-2023 tract population weightsSourceArea Deprivation Index counties in the country rank above the highest of them. Those counties are home to 3.3%3.3% percent of residentsEstimandshare of residents living in counties ranked above the highest county used, 2019-2023 tract populationWeights2019-2023 tract populationPopulationresidents of the 50 states and DCPeriod2019-2023SourceArea Deprivation Index of residents, and every one has fewer than 250,000250,000 residentsEstimandpopulation size at which WONDER names a county in the linked file (a definition)Weightsnone (definition)Populationcounties that CDC WONDER linked birth and infant death names individuallyPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death residents, so WONDER does not name them. The most deprived large county is less deprived than the most deprived places in the nation, which is part of why the County Health Rankings check below matters.

    A county-year with fewer than 1010 infant deathsEstimanda cell with fewer deaths than this is withheld (a definition)Weightsnone (definition)Populationcells of the WONDER linked birth and infant death filesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death deaths is withheld, which makes a county's published years its high years. Pooling a county over only those years would overstate its rate, so a county with any withheld year is left out whole. That removes 2121 countiesEstimandcount of counties left out of the county ratesWeightsnone (full count)Populationnamed counties with a withheld death count in at least one year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death counties, which hold 2.6%2.6% percent of live birthsEstimandshare of births in the counties left out because a year is withheldWeightsnone (full count)Populationlive births in the named countiesPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of births in the named counties and account for 4444 withheld county-yearsEstimandcount of county-years with 1 to 9 infant deaths, which WONDER withholdsWeightsnone (full count)Populationcounty-year rows of the named countiesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death withheld county-years. Each of those holds fewer than 1010 infant deathsEstimanda cell with fewer deaths than this is withheld (a definition)Weightsnone (definition)Populationcells of the WONDER linked birth and infant death filesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death deaths, so together they could hold at most 0.6%0.6% percent of infant deathsEstimandlargest share of deaths the withheld county-years could hold: 9 deaths in each withheld county-year, over published deaths plus that limitWeightsnone (an upper limit from the cell count)Populationinfant deaths in the named countiesPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of infant deaths in the named counties. The wider problem of what suppression leaves out of death data is the subject of Chapter 10.3, Suppressed counties in death data.

    The rate rises across the quarters of counties, from 3.9 (95% CI 3.7 to 4.1)3.9 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countiesInterval95% CI 3.7 to 4.1n60 countiesWeightsbirths in each countyPopulationlive births in the least deprived quarter of the counties used, by county deprivation rankPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in the least deprived to 7.2 (95% CI 6.7 to 7.6)7.2 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countiesInterval95% CI 6.7 to 7.6n60 countiesWeightsbirths in each countyPopulationlive births in the most deprived quarter of the counties used, by county deprivation rankPeriod2018 to 2022SourceCDC WONDER linked birth and infant death in the most deprived (Table 3). The difference is 3.3 (95% CI 2.8 to 3.8)3.3 infant deaths per 1,000 live birthsEstimanddifference of two pooled rates, bootstrap interval over counties with shared drawsInterval95% CI 2.8 to 3.8n240 countiesWeightsbirths in each countyPopulationlive births in the counties used, most deprived quarter minus least deprived quarterPeriod2018 to 2022SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death, and the rate in the most deprived quarter is 1.9 (95% CI 1.7 to 2.0)1.9 ratio of ratesEstimandratio of two pooled rates, bootstrap interval over counties with shared drawsInterval95% CI 1.7 to 2.0n240 countiesWeightsbirths in each countyPopulationlive births in the counties used, most deprived quarter over least deprived quarterPeriod2018 to 2022SourceCDC WONDER linked birth and infant death times the rate in the least deprived. Across all of these counties the rate moves with the rank, with a births-weighted correlation of 0.80 (95% CI 0.73 to 0.86)0.80 correlation coefficientEstimandbirths-weighted correlation of the county rate with county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.73 to 0.86n240 countiesWeightsbirths in each countyPopulationlive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022Period2018 to 2022SourceCDC WONDER linked birth and infant death. The slope is 0.63 (95% CI 0.54 to 0.71)0.63 infant deaths per 1,000 live births for each ten points of county deprivation rankEstimandbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.54 to 0.71n240 countiesWeightsbirths in each countyPopulationlive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022Period2018 to 2022SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death for each 1010 points of county deprivation rankEstimandthe step in the county deprivation rank for which a slope is reported (a definition)Weightsnone (definition)PopulationcountiesPeriodall years (a definition)SourceArea Deprivation Index-point step in the rank.

    A second source reaches smaller counties. County Health Rankings rates for 2015 to 2021 cover 1,2061,206 countiesEstimandcount of counties with at least 20 infant deaths in the periodWeightsnone (full count)Populationcounties and county equivalents with a County Health Rankings infant mortality rate and an ADIPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings counties of every size that reach the floor of 2020 infant deathsEstimandfewest infant deaths in the period for which County Health Rankings publishes a county rate, which is also the book's map floor (a definition)Weightsnone (definition)Populationcounties on the mapPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings deaths. In tenths of those counties the rate is 4.0 (95% CI 3.8 to 4.2)4.0 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates, bootstrap interval over countiesInterval95% CI 3.8 to 4.2n120 countiesWeightsbirths in each county (County Health Rankings denominator)Populationlive births in the least deprived tenth of counties with a County Health Rankings ratePeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings in the least deprived tenth and 8.8 (95% CI 8.1 to 9.5)8.8 infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates, bootstrap interval over countiesInterval95% CI 8.1 to 9.5n121 countiesWeightsbirths in each county (County Health Rankings denominator)Populationlive births in the most deprived tenth of counties with a County Health Rankings ratePeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings in the most deprived, with a correlation of 0.76 (95% CI 0.71 to 0.80)0.76 correlation coefficientEstimandbirths-weighted correlation of the county rate with county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.71 to 0.80n1,206 countiesWeightsbirths in each county (County Health Rankings denominator)Populationlive births in counties with a County Health Rankings ratePeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings. The line is not monotone: it rises over the lower deciles and dips across the eighth and ninth before the most deprived tenth. The interval is wider in the most deprived tenth, whose counties have fewer births.

    The rise holds within states and within groups of mothers

    Counties in the South have higher deprivation ranks and higher rates, so the rise could come from differences between states alone. Comparing counties inside the same state, with a fixed effect for each state, the slope is 0.62 (95% CI 0.47 to 0.84)0.62 infant deaths per 1,000 live births for each ten points of county deprivation rankEstimandbirths-weighted slope of the county rate on county deprivation rank with state fixed effects, bootstrap interval over statesInterval95% CI 0.47 to 0.84n44 statesWeightsbirths in each countyPopulationlive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022Period2018 to 2022SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death for each 1010 points of county deprivation rankEstimandthe step in the county deprivation rank for which a slope is reported (a definition)Weightsnone (definition)PopulationcountiesPeriodall years (a definition)SourceArea Deprivation Index-point step, nearly the same as across all counties (Table 4). It is also nearly the same when only births in 2018 and 2019 are used, at 0.62 (95% CI 0.52 to 0.71)0.62 infant deaths per 1,000 live births for each ten points of county deprivation rankEstimandbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.52 to 0.71n240 countiesWeightsbirths in each countyPopulationlive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022, deaths and births in 2018 and 2019 onlyPeriod2018 and 2019SourceCDC WONDER linked birth and infant death, the only years for which WONDER reports the mother's race.

    For births to white mothers, in the 203203 countiesEstimandcount of countiesWeightsnone (full count)Populationcounties used that publish white infant deaths in both 2018 and 2019Periodinfant deaths and live births in 2018 and 2019SourceCDC WONDER linked birth and infant death counties that publish them in both years and hold 93.9%93.9% percent of live birthsEstimandshare of those births in counties that publish the group in both yearsWeightsnone (full count)Populationlive births to white mothers in the counties usedPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of those births, the slope is 0.36 (95% CI 0.29 to 0.44)0.36 infant deaths per 1,000 live births for each ten points of county deprivation rankEstimandbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.29 to 0.44n203 countiesWeightsbirths in each countyPopulationlive births to white mothers (single race, any ethnicity) in the counties used that publish the group in both yearsPeriod2018 and 2019SourceCDC WONDER linked birth and infant death. For births to Black mothers, in the 115115 countiesEstimandcount of countiesWeightsnone (full count)Populationcounties used that publish Black infant deaths in both 2018 and 2019Periodinfant deaths and live births in 2018 and 2019SourceCDC WONDER linked birth and infant death counties that do and hold 82.5%82.5% percent of live birthsEstimandshare of those births in counties that publish the group in both yearsWeightsnone (full count)Populationlive births to Black mothers in the counties usedPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of those births, it is 0.82 (95% CI 0.62 to 1.01)0.82 infant deaths per 1,000 live births for each ten points of county deprivation rankEstimandbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervalInterval95% CI 0.62 to 1.01n115 countiesWeightsbirths in each countyPopulationlive births to Black mothers (single race, any ethnicity) in the counties used that publish the group in both yearsPeriod2018 and 2019SourceCDC WONDER linked birth and infant death. The white slope is smaller than the slope for all births, and the Black slope is larger than the white slope.

    Counties with higher ranks also have a larger share of births to Black mothers, 11.1%11.1% percent of live birthsEstimandshare of births to Black mothers (single race, any ethnicity) over all births, in the county-years where WONDER publishes the group's births; a county-year with no published count leaves both the numerator and the denominatorWeightsnone (full counts of births)Populationlive births in the least deprived quarter of the counties used, by county deprivation rankPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of births in the least deprived quarter and 31.1%31.1% percent of live birthsEstimandshare of births to Black mothers (single race, any ethnicity) over all births, in the county-years where WONDER publishes the group's births; a county-year with no published count leaves both the numerator and the denominatorWeightsnone (full counts of births)Populationlive births in the most deprived quarter of the counties used, by county deprivation rankPeriod2018 and 2019SourceCDC WONDER linked birth and infant deathNoteWebb County, TX has no published count of births to Black mothers in 2 county-years, so those county-years are left out. Counting them as zero would give 30.7% for this quarter. in the most deprived in 2018 and 2019. The slope for all births therefore combines a rise within each group with a shift in the mix of mothers. A slope across counties describes places. It does not say that a family moved to a less deprived county would see a different outcome.

    The Black-white gap appears in every state that publishes both groups

    The linked file reports the mother's race only for 2018 and 2019, and WONDER counts mothers by single race, with Hispanic mothers included in each group. In those years the rate was 10.3 (95% CI 10.1 to 10.5)10.3 infant deaths per 1,000 live birthsEstimandcrude rate from state counts, normal intervalInterval95% CI 10.1 to 10.5n12,953 infant deathsWeightsnone (crude rate from counts)Populationlive births to Black mothers (single race, any ethnicity) in the United States, states with a published countPeriod2018 and 2019SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death births to Black mothers, 4.7 (95% CI 4.7 to 4.8)4.7 infant deaths per 1,000 live birthsEstimandcrude rate from state counts, normal intervalInterval95% CI 4.7 to 4.8n26,516 infant deathsWeightsnone (crude rate from counts)Populationlive births to white mothers (single race, any ethnicity) in the United States, states with a published countPeriod2018 and 2019SourceCDC WONDER linked birth and infant death for white mothers and 3.9 (95% CI 3.7 to 4.1)3.9 infant deaths per 1,000 live birthsEstimandcrude rate from state counts, normal intervalInterval95% CI 3.7 to 4.1n2,051 infant deathsWeightsnone (crude rate from counts)Populationlive births to Asian or Pacific Islander mothers (single race, any ethnicity) in the United States, states with a published countPeriod2018 and 2019SourceCDC WONDER linked birth and infant death for Asian or Pacific Islander mothers, against 5.65.6 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.6 to 5.7n42,421 infant deathsWeightsnone (crude rate from counts)Populationlive births in the 50 states and DCPeriod2018 and 2019SourceCDC WONDER linked birth and infant death for all mothers (Table 5). The Black rate is 2.2 (95% CI 2.1 to 2.2)2.2 ratio of ratesEstimandratio of crude rates, log-normal interval on the two death countsInterval95% CI 2.1 to 2.2n39,469 infant deathsWeightsnone (crude rates from counts)Populationlive births in the United States, Black mothers over white mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death times the white rate, a difference of 5.6 (95% CI 5.4 to 5.8)5.6 infant deaths per 1,000 live birthsEstimanddifference of crude rates, normal interval on the two death countsInterval95% CI 5.4 to 5.8n39,469 infant deathsWeightsnone (crude rates from counts)Populationlive births in the United States, Black mothers minus white mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death. The Black and white rates are the two printed in Chapter 2.1, Birthweight and preterm birth, computed from the same state files.

    WONDER withholds a state-year cell with fewer than 1010 infant deathsEstimanda cell with fewer deaths than this is withheld (a definition)Weightsnone (definition)Populationcells of the WONDER linked birth and infant death filesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death deaths. The withheld cells hold 1.0%1.0% percent of live birthsEstimandshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthsWeightsnone (full counts of births)Populationlive births to Black mothers (single race, any ethnicity) in the United StatesPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of births to Black mothers, 0.1%0.1% percent of live birthsEstimandshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthsWeightsnone (full counts of births)Populationlive births to white mothers (single race, any ethnicity) in the United StatesPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of births to white mothers and 6.7%6.7% percent of live birthsEstimandshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthsWeightsnone (full counts of births)Populationlive births to Asian or Pacific Islander mothers (single race, any ethnicity) in the United StatesPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of births to Asian or Pacific Islander mothers, so those rates describe almost all of the births in each group. For American Indian or Alaska Native mothers the situation differs. WONDER withholds 6666 withheld state-year cellsEstimandcount of state-year cells with 1 to 9 infant deaths, which WONDER withholdsWeightsnone (full count)PopulationAmerican Indian or Alaska Native mothers (single race, any ethnicity) in 50 states and DCPeriodinfant deaths and live births in 2018 and 2019SourceCDC WONDER linked birth and infant death of the 102102 state-year cellsEstimandcount of state-year cellsWeightsnone (full count)PopulationAmerican Indian or Alaska Native mothers (single race, any ethnicity) in 50 states and DCPeriodinfant deaths and live births in 2018 and 2019SourceCDC WONDER linked birth and infant death state-year cells, and the published cells hold only 65.6%65.6% percent of live birthsEstimandshare of births in state-years whose deaths WONDER publishesWeightsnone (full counts of births)Populationlive births to American Indian or Alaska Native mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death of their births. A pooled rate over those cells would describe the states with the most deaths, so none is shown.

    Infants of Black mothers died at a higher rate than infants of white mothers in each of the 3636 statesEstimandcount of statesWeightsnone (full count)Populationstates that publish infant deaths for both Black and white mothers in both 2018 and 2019Periodinfant deaths and live births in 2018 and 2019SourceCDC WONDER linked birth and infant death states that publish both groups in both years, which hold 98.0%98.0% percent of live birthsEstimandshare of those births in the states shownWeightsnone (full counts of births)Populationlive births to Black mothers (single race, any ethnicity) in the United StatesPeriod2018 and 2019SourceCDC WONDER linked birth and infant death of births to Black mothers (Table 6). In none of them does the interval for one group touch the interval for the other. The ratio has a median of 2.12.1 ratio of ratesEstimandmedian of the state ratiosn36 statesWeightsnone (each state counts once)Populationlive births in the states shown, Black mothers over white mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death across these states. It is smallest in Mississippi, at 1.7 (95% CI 1.4 to 1.9)1.7 ratio of ratesEstimandratio of crude rates in the state with the smallest ratio, log-normal interval on the two death countsInterval95% CI 1.4 to 1.9n621 infant deathsWeightsnone (crude rates from counts)Populationlive births in Mississippi, Black mothers over white mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death, and largest in Delaware, at 3.2 (95% CI 2.3 to 4.7)3.2 ratio of ratesEstimandratio of crude rates in the state with the largest ratio, log-normal interval on the two death countsInterval95% CI 2.3 to 4.7n123 infant deathsWeightsnone (crude rates from counts)Populationlive births in Delaware, Black mothers over white mothers (single race, any ethnicity)Period2018 and 2019SourceCDC WONDER linked birth and infant death.

    Mississippi has the smallest ratio and also the highest white rate of the states shown, 6.7 (95% CI 5.8 to 7.5)6.7 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 5.8 to 7.5n263 infant deathsWeightsnone (crude rate from counts)Populationlive births to white mothers (single race, any ethnicity) in MississippiPeriod2018 and 2019SourceCDC WONDER linked birth and infant death. The lowest white rate is 3.2 (95% CI 2.9 to 3.5)3.2 infant deaths per 1,000 live birthsEstimandcrude rate from the death count, normal intervalInterval95% CI 2.9 to 3.5n457 infant deathsWeightsnone (crude rate from counts)Populationlive births to white mothers (single race, any ethnicity) in New JerseyPeriod2018 and 2019SourceCDC WONDER linked birth and infant death, in New Jersey. The white rate itself therefore differs across states, and the state ranking in Table 1 is not only a difference in racial composition.

    A rate for a racial group in a state averages over mothers whose circumstances differ greatly, so these comparisons do not identify which circumstances matter. Chapter 2.1, Birthweight and preterm birth reports studies of income support and insurance during pregnancy and the birth outcomes that precede these deaths.

    Age at death is published for only a few counties

    WONDER's county file splits infant deaths into five age groups, from under an hour to the end of the first year. It withholds each county-year-age cell with fewer than 1010 infant deathsEstimanda cell with fewer deaths than this is withheld (a definition)Weightsnone (definition)Populationcells of the WONDER linked birth and infant death filesPeriodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death deaths, which is 4,3284,328 withheld cellsEstimandcount of cells with 1 to 9 infant deaths, which WONDER withholdsWeightsnone (full count)Populationnamed counties, five age groups, 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death of the 6,5256,525 county-year-age cellsEstimandcount of cellsWeightsnone (full count)Populationnamed counties, five age groups, 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death cells for the named counties. Only 1414 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties that publish all five age groups in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death counties publish every cell in every year (Table 7). They are among the largest counties and hold 23.6%23.6% percent of live birthsEstimandshare of births in the counties shownWeightsnone (full count)Populationlive births in the named countiesPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of births in the named counties. The age groups cannot be summed for any other county without filling in withheld cells, so this section covers these counties and no others.

    In these counties the neonatal rate is 3.6 (95% CI 3.1 to 4.1)3.6 infant deaths per 1,000 live birthsEstimandpooled neonatal (under 28 days) death rate, bootstrap interval over countiesInterval95% CI 3.1 to 4.1n14 countiesWeightsbirths in each countyPopulationlive births in the 14 counties that publish all five age groupsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death and the postneonatal rate is 1.6 (95% CI 1.4 to 1.9)1.6 infant deaths per 1,000 live birthsEstimandpooled postneonatal (28 to 364 days) death rate, bootstrap interval over countiesInterval95% CI 1.4 to 1.9n14 countiesWeightsbirths in each countyPopulationlive births in the 14 counties that publish all five age groupsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death. Neonatal deaths are 68.7% (95% CI 67.4% to 70.2%)68.7% percent of infant deathsEstimandpooled share that are neonatal deaths (under 28 days), bootstrap interval over countiesInterval95% CI 67.4% to 70.2%n14 countiesWeightsinfant deaths in each countyPopulationinfant deaths in the 14 counties that publish all five age groupsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of infant deaths, and 42.3% (95% CI 40.5% to 44.2%)42.3% percent of infant deathsEstimandpooled share that are deaths in the first 24 hours, bootstrap interval over countiesInterval95% CI 40.5% to 44.2%n14 countiesWeightsinfant deaths in each countyPopulationinfant deaths in the 14 counties that publish all five age groupsPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of infant deaths occur on the first day of life.

    Both rates are higher where the deprivation rank is higher. Dividing the 1414 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties that publish all five age groups in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death counties at the median rank, the neonatal rate in the more deprived group is 1.5 (95% CI 1.2 to 1.8)1.5 ratio of ratesEstimandratio of pooled neonatal death rates, bootstrap interval over counties with shared drawsInterval95% CI 1.2 to 1.8n14 countiesWeightsbirths in each countyPopulationlive births in the 14 counties that publish all five age groups, the counties above the median deprivation rank over those below itPeriod2018 to 2022SourceCDC WONDER linked birth and infant death times the rate in the less deprived group, and the postneonatal rate is 1.6 (95% CI 1.3 to 2.1)1.6 ratio of ratesEstimandratio of pooled postneonatal death rates, bootstrap interval over counties with shared drawsInterval95% CI 1.3 to 2.1n14 countiesWeightsbirths in each countyPopulationlive births in the 14 counties that publish all five age groups, the counties above the median deprivation rank over those below itPeriod2018 to 2022SourceCDC WONDER linked birth and infant death times. The intervals overlap, so these counties cannot show whether the postneonatal rate rises faster with deprivation. The comparison of the United States with Europe placed the American disadvantage in the postneonatal period, among infants of lower socioeconomic status.[1] These counties have no European comparison and too few observations to test that.

    Infant mortality rises with deprivation under all four rankings

    Table 8 ranks the 1,2061,206 countiesEstimandcount of counties in the common sample of the ranking comparisonWeightsnone (full count)Populationcounties with the outcome and all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings counties that have a County Health Rankings rate and all four rankings in four ways. Ranked by the ADI on this common sample, the rate is 4.0 (95% CI 3.8 to 4.2)4.0 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 3.8 to 4.2n120 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe least deprived tenth of counties ranked by Area Deprivation Index, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings deaths per 1,0001,000 live birthsEstimandthe denominator of an infant mortality rate (a definition)Weightsnone (definition)Populationall live birthsPeriodall years (a definition)SourceCDC WONDER linked birth and infant death in the least deprived tenth and 8.7 (95% CI 8.0 to 9.4)8.7 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 8.0 to 9.4n121 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe most deprived tenth of counties ranked by Area Deprivation Index, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings in the most deprived, and the rank correlation between tenth and rate is +0.95+0.95 rank correlationEstimandSpearman rank correlation between bin order and bin mean, each bin counted onceWeightseach bin counted oncePopulationthe bins of counties ranked by Area Deprivation IndexPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings. Under the standardized index the rate is 4.0 (95% CI 3.8 to 4.2)4.0 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 3.8 to 4.2n120 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe least deprived tenth of counties ranked by Standardized index, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings in the least deprived tenth and 7.0 (95% CI 6.1 to 8.3)7.0 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 6.1 to 8.3n121 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe most deprived tenth of counties ranked by Standardized index, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings in the most deprived, with a correlation of +0.92+0.92 rank correlationEstimandSpearman rank correlation between bin order and bin mean, each bin counted onceWeightseach bin counted oncePopulationthe bins of counties ranked by Standardized indexPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, and it is highest in the eighth tenth. Under median household income the two ends are 3.9 (95% CI 3.7 to 4.1)3.9 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 3.7 to 4.1n120 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe least deprived tenth of counties ranked by Median household income, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings and 9.0 (95% CI 8.5 to 9.4)9.0 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 8.5 to 9.4n121 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe most deprived tenth of counties ranked by Median household income, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, with a correlation of +1.00+1.00 rank correlationEstimandSpearman rank correlation between bin order and bin mean, each bin counted onceWeightseach bin counted oncePopulationthe bins of counties ranked by Median household incomePeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, and under the bachelor's degree share they are 4.3 (95% CI 4.1 to 4.6)4.3 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 4.1 to 4.6n120 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe least deprived tenth of counties ranked by Bachelor's degree share, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings and 7.8 (95% CI 7.2 to 8.5)7.8 Infant deaths per 1,000 live birthsEstimandbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesInterval95% CI 7.2 to 8.5n121 countiesWeightsbirths in each county (County Health Rankings denominator)Populationthe most deprived tenth of counties ranked by Bachelor's degree share, among the counties with all four rankingsPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, with a correlation of +0.99+0.99 rank correlationEstimandSpearman rank correlation between bin order and bin mean, each bin counted onceWeightseach bin counted oncePopulationthe bins of counties ranked by Bachelor's degree sharePeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings, so none of the three counts as a change under the book's rule (Chapter 9.1, How far one ranking goes).

    What these data cannot show

    The county gradient describes the 240240 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties with a published death count in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death largest counties, which hold 62.3%62.3% percent of live births in the United StatesEstimandshare of births in the counties usedn18,484,949 birthsWeightsnone (full count)Populationlive births in the 50 states and DCPeriod2018 to 2022SourceCDC WONDER linked birth and infant death of births. WONDER pools the rest by state. The County Health Rankings check reaches smaller counties but leaves out those that do not reach 2020 infant deathsEstimandfewest infant deaths in the period for which County Health Rankings publishes a county rate, which is also the book's map floor (a definition)Weightsnone (definition)Populationcounties on the mapPeriodinfant deaths and live births in 2015 to 2021SourceCounty Health Rankings deaths in the period, and the counties just above that floor have the least precise rates on the map. The county rates describe counties that publish a figure, which are not a sample of all counties, and the age-at-death figure covers only 1414 countiesEstimandcount of countiesWeightsnone (full count)Populationnamed counties that publish all five age groups in every year 2018 to 2022Periodinfant deaths and live births in 2018 to 2022SourceCDC WONDER linked birth and infant death of them.

    Sources and periods differ, and each is named where it appears. WONDER covers 2018 to 2022 for states and counties and 2018 and 2019 for mother's race, and County Health Rankings covers 2015 to 2021. WONDER's race groups are single races that include Hispanic mothers, so its white group is not the non-Hispanic white group of other sources, and Hispanic origin is not in the files used here. American Indian or Alaska Native mothers are not shown.

    The Area Deprivation Index understates deprivation in high-cost cities (Chapter 1.1, What the deprivation index measures) and draws on the American Community Survey for 2019 to 2023, while the deaths are from 2018 to 2022. A county's rank averages over tracts that differ within the county, and it describes no family's circumstances. Patterns across counties and states are patterns of places, not of individual infants, a limit known as ecological inferenceEcological inferenceDrawing conclusions about individuals from data about places or groups. A pattern across counties need not hold for the people inside them..

    Finally, the files carry no cause of death, no gestational age or birthweight, and no information on mothers beyond race, so nothing here identifies a mechanism. The rates are crude period rates, and 2020 to 2022 include the pandemic. Intervals for state and race rates treat deaths as independent and leave out differences between places within each rate, while the county figures resample whole counties.

    Tables

    Table 1. Infant mortality ran from 3.7 per 1,000 in Massachusetts and New Hampshire to 8.7 in Mississippi

    Infant deaths per 1,000, by state and DC, 2018 to 2022; the first tab maps the rates and the second ranks them with intervals

    Table 1.1. Map of states

    7 of the 10 states with the highest infant mortality rates are in the South, which has 6.3 deaths per 1,000 against 5.1 elsewhere

    Infant deaths per 1,000, by state and DC, 2018 to 2022

    conf_highconf_lownratestate
    6.745.3548,1036.05AK
    7.496.87290,2267.18AL
    8.037.22180,2697.63AR
    5.835.36393,5085.60AZ
    4.204.032,161,3704.11CA
    5.034.54312,5804.79CO
    4.684.05173,4454.36CT
    6.695.2543,9005.97DC
    6.625.3052,8735.96DE
    6.115.821,091,9085.97FL
    6.946.54625,2196.74GA
    5.974.9580,7095.46HI
    5.044.41184,8894.73IA
    5.384.55109,8174.96ID
    5.985.62678,7805.80IL
    7.046.53400,7166.79IN
    6.265.54175,1385.90KS
    6.155.56263,1885.86KY
    7.887.25289,8007.57LA
    3.883.48342,3753.68MA
    6.185.67346,8795.92MD
    6.335.1259,7285.73ME
    6.626.19529,2936.40MI
    4.854.38325,2544.61MN
    6.465.94353,1196.20MO
    9.178.31178,9408.74MS
    5.404.2555,7894.82MT
    6.976.55596,4376.76NC
    5.804.5550,8285.17ND
    5.955.12123,4885.54NE
    4.203.2360,3273.71NH
    43.66503,1523.83NJ
    5.905.03110,9075.46NM
    5.705.01171,2865.35NV
    4.364.111,075,6314.23NY
    7.146.74656,8086.94OH
    7.136.48243,3086.81OK
    4.604.03204,2734.31OR
    5.895.52663,4705.70PA
    5.194.0151,5154.60RI
    7.246.63284,4166.93SC
    7.466.1156,8726.79SD
    6.856.35403,8726.60TN
    5.565.351,887,7485.45TX
    5.454.87232,2175.16UT
    6.085.65483,4765.87VA
    4.943.3926,6264.17VT
    4.644.24421,3104.44WA
    6.095.55309,7925.82WI
    7.456.3587,8346.90WV
    6.614.9331,5415.77WY

    Table 1.2. States ranked

    Mississippi's rate of 8.7 is 2.4 times Massachusetts's 3.7

    Infant deaths per 1,000 with 95% intervals, by state and DC, 2018 to 2022, ranked from the highest rate

    conf_highconf_lownratestate
    9.178.31178,9408.74Mississippi
    8.037.22180,2697.63Arkansas
    7.887.25289,8007.57Louisiana
    7.496.87290,2267.18Alabama
    7.146.74656,8086.94Ohio
    7.246.63284,4166.93South Carolina
    7.456.3587,8346.90West Virginia
    7.136.48243,3086.81Oklahoma
    7.466.1156,8726.79South Dakota
    7.046.53400,7166.79Indiana
    6.976.55596,4376.76North Carolina
    6.946.54625,2196.74Georgia
    6.856.35403,8726.60Tennessee
    6.626.19529,2936.40Michigan
    6.465.94353,1196.20Missouri
    6.745.3548,1036.05Alaska
    6.695.2543,9005.97District of Columbia
    6.115.821,091,9085.97Florida
    6.625.3052,8735.96Delaware
    6.185.67346,8795.92Maryland
    6.265.54175,1385.90Kansas
    6.085.65483,4765.87Virginia
    6.155.56263,1885.86Kentucky
    6.095.55309,7925.82Wisconsin
    5.985.62678,7805.80Illinois
    6.614.9331,5415.77Wyoming
    6.335.1259,7285.73Maine
    5.895.52663,4705.70Pennsylvania
    5.835.36393,5085.60Arizona
    5.955.12123,4885.54Nebraska
    5.974.9580,7095.46Hawaii
    5.905.03110,9075.46New Mexico
    5.565.351,887,7485.45Texas
    5.705.01171,2865.35Nevada
    5.804.5550,8285.17North Dakota
    5.454.87232,2175.16Utah
    5.384.55109,8174.96Idaho
    5.404.2555,7894.82Montana
    5.034.54312,5804.79Colorado
    5.044.41184,8894.73Iowa
    4.854.38325,2544.61Minnesota
    5.194.0151,5154.60Rhode Island
    4.644.24421,3104.44Washington
    4.684.05173,4454.36Connecticut
    4.604.03204,2734.31Oregon
    4.364.111,075,6314.23New York
    4.943.3926,6264.17Vermont
    4.204.032,161,3704.11California
    43.66503,1523.83New Jersey
    4.203.2360,3273.71New Hampshire
    3.883.48342,3753.68Massachusetts

    Note: Rates are infant deaths in 2018 to 2022 over live births in the same years, pooled over the five years, for the 51 jurisdictions. WONDER publishes every state total in full, so no state has a withheld cell.

    Note: Intervals are 95% intervals on the death counts (gamma for small counts and normal for large ones, the NCHS convention described in the methods note); they treat deaths as independent and leave out differences between counties within a state.

    Note: WONDER weights infant deaths, so a total can differ from the unweighted number of records by rounding.

    Source: CDC WONDER linked birth and infant death, 2018-2022; crude rates from full counts

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_by_state.json

    Table 2. 85.1% of the counties in the highest tenth of infant mortality rates are in the South, which holds 49.3% of the 1,206 counties that publish a rate

    Infant deaths per 1,000, by county, County Health Rankings 2024, infant deaths and live births in 2015 to 2021

    No inline rows: the values of Table 2 are in /data/infant-mortality/imr_county_map.json.

    Note: County Health Rankings publishes a county's infant mortality rate only from 20 infant deaths in the period, which leaves out most small counties and is the same floor the book uses for death maps. Gray counties are not zero; they are counties where the rate cannot be published.

    Note: The period is 2015 to 2021, not the 2018 to 2022 of the WONDER figures. Across the 240 large counties the two sources correlate at 0.980.

    Note: The key runs from 3.7 to 10.6, the fifth to ninety-fifth percentile of the mapped county rates. Counties beyond either end take the end color, so the end colors include the tails of the distribution.

    Note: Connecticut is shown as its eight legacy counties, the coding of the source. Alaska is drawn. Puerto Rico is not drawn.

    Source: County Health Rankings 2024 (NCHS mortality and natality counts; window and 20-death rule as in the CHR 2024 technical documentation, see the dataset note), infant deaths and live births in 2015-2021; crude rates from full counts

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_county_map.json

    Table 3. Infant mortality rises from 3.9 per 1,000 in the least deprived quarter of large counties to 7.2 in the most deprived

    Infant deaths per 1,000 by county deprivation, WONDER 2018 to 2022 for the large counties and County Health Rankings 2015 to 2021 for all counties with a rate

    Table 3.1. Large counties, 2018 to 2022

    Across 240 large counties the infant mortality rate moves with the deprivation rank, a correlation of 0.80

    Infant deaths per 1,000 against the county deprivation rank, one dot per county, 2018 to 2022, with births-weighted quartile means

    adibirthsconf_highconf_lowcountyimr
    27.27247125.683.95Ada County, ID4.82
    31.50309966.274.63Adams County, CO5.45
    7.82873163.813.04Alameda County, CA3.42
    60.06619766.975.71Allegheny County, PA6.34
    67.85261598.096.05Allen County, IN7.07
    37.23189086.144.06Anchorage Borough, AK5.02
    26.31343285.233.80Anne Arundel County, MD4.52
    41.11206805.513.63Anoka County, MN4.50
    25.25375215.534.12Arapahoe County, CO4.82
    54.06138997.644.95Atlantic County, NJ6.19
    42.28474397.245.79Baltimore County, MD6.51
    64.94372839.787.87Baltimore city, MD8.82
    64.57303407.685.83Bell County, TX6.76
    19.42452553.322.34Bergen County, NJ2.83
    60.09228477.105.07Berks County, PA6.08
    54.44336655.944.40Bernalillo County, NM5.17
    59.171300376.545.69Bexar County, TX6.11
    49.43234856.164.31Brazoria County, TX5.24
    48.90257207.235.29Brevard County, FL6.26
    34.02279925.093.55Bristol County, MA4.32
    31.09915775.394.48Bronx County, NY4.94
    40.971052055.564.69Broward County, FL5.12
    29.71281964.122.73Bucks County, PA3.37
    40.10225484.612.97Burlington County, NJ3.73
    58.33218588.506.23Butler County, OH7.37
    76.411475913.479.97Caddo Parish, LA11.72
    54.47306606.484.80Camden County, NJ5.64
    84.05303066.104.46Cameron County, TX5.28
    35.04247867.415.42Charleston County, SC6.41
    56.20180408.445.97Chatham County, GA7.21
    26.68271904.923.39Chester County, PA4.16
    40.91199957.024.88Chesterfield County, VA5.95
    39.241284865.714.92Clark County, NV5.32
    26.64275804.933.41Clark County, WA4.17
    71.44180459.947.24Clayton County, GA8.59
    59.97138018.415.57Cleveland County, OK6.88
    37.38442856.114.73Cobb County, GA5.42
    26.55590794.583.55Collin County, TX4.06
    12.71589524.223.24Contra Costa County, CA3.73
    47.082829786.275.70Cook County, IL5.99
    30.73139376.023.66Cumberland County, ME4.74
    72.53265029.367.17Cumberland County, NC8.26
    69.33669658.627.27Cuyahoga County, OH7.94
    35.84252204.342.83Dakota County, MN3.53
    51.841846356.685.96Dallas County, TX6.32
    37.44284635.664.04Dane County, WI4.85
    62.88166197.795.33Dauphin County, PA6.56
    38497967.435.99Davidson County, TN6.71
    26.64247835.754.01Davis County, UT4.88
    44.32512447.616.17DeKalb County, GA6.89
    47.79319727.265.51Delaware County, PA6.38
    31.79523314.763.65Denton County, TX4.20
    21.31458895.364.10Denver County, CO4.73
    16.41439006.695.25District of Columbia, DC5.97
    55.92402056.945.40Douglas County, NE6.17
    34.30491624.393.30DuPage County, IL3.84
    41.88206486.904.82Durham County, NC5.86
    55.54637178.477.10Duval County, FL7.78
    61.83283859.387.25East Baton Rouge Parish, LA8.31
    32.73456696.254.88El Paso County, CO5.56
    74.50569314.903.81El Paso County, TX4.36
    62.29475986.995.57Erie County, NY6.28
    74.57135899.126.18Erie County, PA7.65
    62.76187639.276.72Escambia County, FL7.99
    21.97420434.403.22Essex County, MA3.81
    33.03498645.404.19Essex County, NJ4.79
    14.29645874.283.33Fairfax County, VA3.81
    26.85490894.333.24Fairfield County, CT3.79
    55.11187986.894.71Fayette County, KY5.80
    62.43220199.617.19Forsyth County, NC8.40
    37.634597753.79Fort Bend County, TX4.39
    55.13892648.116.97Franklin County, OH7.54
    46.34702676.505.36Fresno County, CA5.93
    36.01618567.686.36Fulton County, GA7.02
    50.28195526.294.25Galveston County, TX5.27
    73.71222428.416.16Genesee County, MI7.28
    68.78165167.314.92Greene County, MO6.12
    52.19318936.174.56Greenville County, SC5.36
    62.39297639.557.45Guilford County, NC8.50
    41.21544306.315.04Gwinnett County, GA5.68
    33.43188895.803.78Hamilton County, IN4.71
    59.80524888.797.25Hamilton County, OH8.02
    51.80217247.365.25Hamilton County, TN6.31
    54.48240276.254.40Hampden County, MA5.33
    55.593265385.905.39Harris County, TX5.65
    47.60449455.384.10Hartford County, CT4.74
    36.21753085.154.17Hennepin County, MN4.66
    42.82186637.234.99Henrico County, VA6.11
    83.04690185.144.13Hidalgo County, TX4.64
    45.98852897.126.03Hillsborough County, FL6.58
    35.48207924.903.14Hillsborough County, NH3.94
    11.87577126.024.82Honolulu County, HI5.42
    57.80159797.975.43Horry County, SC6.70
    19.35165186.364.11Howard County, MD5.15
    24.794791332.09Hudson County, NJ2.55
    68148008.455.74Ingham County, MI7.09
    64.74436608.046.44Jackson County, MO7.24
    62.60406469.417.62Jefferson County, AL8.51
    19.12278595.233.67Jefferson County, CO4.45
    60.18475036.765.36Jefferson County, KY6.06
    75.11163509.526.75Jefferson County, TX8.13
    60.17274297.405.50Jefferson Parish, LA6.45
    35.27348594.713.38Johnson County, KS4.04
    60.96142356.764.27Kalamazoo County, MI5.41
    45.72290656.064.40Kane County, IL5.23
    51.75413306.134.71Kent County, MI5.42
    52.63630256.175Kern County, CA5.59
    12.921185974.303.59King County, WA3.95
    9.961773043.653.11Kings County, NY3.38
    52.49261546.985.10Knox County, TN6.04
    52.55173806.934.63Lake County, FL5.70
    42.15342794.793.43Lake County, IL4.11
    65.67276027.865.90Lake County, IN6.88
    55.73186576.414.31Lancaster County, NE5.36
    49.56348896.564.96Lancaster County, PA5.76
    37.21157636.033.80Lane County, OR4.82
    24.18154785.573.41Larimer County, CO4.39
    47.61352176.444.87Lee County, FL5.65
    54.75204976.854.76Lehigh County, PA5.81
    57.971436811.137.94Leon County, FL9.54
    62.02163007.334.88Lexington County, SC6.01
    64.59160037.194.75Lorain County, OH5.87
    14.235076274.053.70Los Angeles County, CA3.87
    11.94246244.272.76Loudoun County, VA3.45
    67.26201156.384.36Lubbock County, TX5.37
    74.432568410.207.87Lucas County, OH9.03
    75.48160157.114.69Luzerne County, PA5.81
    58.72446015.684.36Macomb County, MI5.02
    53.80216997.075Madison County, AL6.04
    46.74177136.754.54Manatee County, FL5.65
    36.112534345.685.10Maricopa County, AZ5.39
    66.59176078.415.91Marion County, FL7.16
    67.02699598.797.45Marion County, IN8.12
    38.99200474.913.12Marion County, OR3.94
    40.70738095.694.66Mecklenburg County, NC5.18
    42.31191255.323.41Merced County, CA4.29
    42.50204045.974.03Mercer County, NJ5
    37.241468495.114.41Miami-Dade County, FL4.76
    14.53810443.072.36Middlesex County, MA2.71
    29.18430154.403.23Middlesex County, NJ3.81
    66.79619399.027.58Milwaukee County, WI8.30
    72.95263219.387.18Mobile County, AL8.28
    20.24300243.762.47Monmouth County, NJ3.06
    65.30383576.915.34Monroe County, NY6.13
    16.90284375.814.17Monterey County, CA4.99
    18.93594755.053.97Montgomery County, MD4.51
    72.95311699.127.12Montgomery County, OH8.12
    31.41424424.403.23Montgomery County, PA3.82
    43.03387095.193.85Montgomery County, TX4.52
    24.43388034.513.27Multnomah County, OR3.89
    13.81691523.292.49Nassau County, NY2.89
    43.82307147.175.40New Castle County, DE6.28
    48.10424445.944.56New Haven County, CT5.25
    8.92757633.102.36New York County, NY2.73
    14.99355153.392.27Norfolk County, MA2.79
    68.22219116.264.33Nueces County, TX5.29
    43.65636655.284.21Oakland County, MI4.74
    35.14478183.392.42Ocean County, NJ2.91
    66.32554277.285.93Oklahoma County, OK6.60
    67.47246766.314.47Onondaga County, NY5.39
    11.181634373.502.95Orange County, CA3.22
    44.12820316.255.21Orange County, FL5.73
    36.70265154.503Orange County, NY3.70
    51.55219098.346.09Orleans Parish, LA7.21
    47.66230485.383.65Osceola County, FL4.51
    38.83739305.194.20Palm Beach County, FL4.69
    55.44261646.204.43Pasco County, FL5.31
    34.54318634.413.06Passaic County, NJ3.73
    62.40995237.536.49Philadelphia County, PA7.01
    26.23556495.734.54Pierce County, WA5.14
    53.40510866.214.91Pima County, AZ5.56
    50.23236316.634.71Pinal County, AZ5.67
    48.07382986.595.06Pinellas County, FL5.82
    23.13260144.342.85Plymouth County, MA3.54
    62.59416098.186.53Polk County, FL7.35
    55.05324155.704.17Polk County, IA4.94
    33.05570707.606.24Prince George's County, MD6.92
    23.33317275.764.20Prince William County, VA4.98
    42.93349966.144.60Providence County, RI5.37
    68.102525410.337.97Pulaski County, AR9.15
    16.431274984.013.35Queens County, NY3.68
    46.60349086.685.07Ramsey County, MN5.87
    64.44232238.145.98Richland County, SC7.06
    15.94255204.993.40Richmond County, NY4.19
    28.371390314.834.12Riverside County, CA4.47
    21.10297483.532.28Rockland County, NY2.86
    41.48212927.365.23Rutherford County, TN6.29
    27.87928125.604.68Sacramento County, CA5.14
    27.27770225.924.88Salt Lake County, UT5.40
    31.951372565.865.07San Bernardino County, CA5.46
    13.981907653.873.33San Diego County, CA3.60
    3.15397503.172.16San Francisco County, CA2.67
    28.64493516.084.78San Joaquin County, CA5.43
    3.18391993.412.35San Mateo County, CA2.88
    17.02273104.863.34Santa Barbara County, CA4.10
    5.051003053.032.39Santa Clara County, CA2.71
    68.53332147.856.06Sedgwick County, KS6.95
    40.38229706.594.65Seminole County, FL5.62
    66.30632319.037.61Shelby County, TN8.32
    17.55483964.042.98Snohomish County, WA3.51
    20.56248945.203.56Solano County, CA4.38
    14.25222663.822.33Sonoma County, CA3.01
    66.48197486.444.39Spartanburg County, SC5.42
    40.64290315.143.61Spokane County, WA4.37
    44.15211565.863.97St. Charles County, MO4.92
    70.571433610.177.13St. Clair County, IL8.65
    71.71167109.186.50St. Joseph County, IN7.84
    53.57543226.565.26St. Louis County, MO5.91
    70.841892710.397.68St. Louis city, MO9.03
    50.80163506.434.15St. Lucie County, FL5.20
    33.77362795.784.31Stanislaus County, CA5.04
    71.61199617.585.35Stark County, OH6.46
    16.54427134.503.32Suffolk County, MA3.91
    19.74770734.323.44Suffolk County, NY3.88
    66.08281167.075.24Summit County, OH6.15
    48.921362536.255.44Tarrant County, TX5.84
    30.13152516.534.16Thurston County, WA5.25
    27.39777564.533.63Travis County, TX4.08
    50.21338455.814.30Tulare County, CA5.05
    64.81438628.176.56Tulsa County, OK7.36
    28.09331014.573.22Union County, NJ3.90
    26.08589545.364.24Utah County, UT4.80
    14.46433724.433.27Ventura County, CA3.85
    38.95268796.514.72Virginia Beach city, VA5.62
    55.90243686.614.72Volusia County, FL5.66
    32641765.884.75Wake County, NC5.31
    21.83309454.473.10Washington County, OR3.78
    28.88255726.644.78Washoe County, NV5.71
    40.20168206.774.46Washtenaw County, MI5.53
    34.74190675.693.70Waukesha County, WI4.62
    72.8410969710.229.05Wayne County, MI9.64
    73.52224215.874.03Webb County, TX4.95
    32.31222854.773.09Weld County, CO3.86
    20.19495304.293.22Westchester County, NY3.76
    66.04143526.784.30Westmoreland County, PA5.43
    43.71353315.874.38Will County, IL5.12
    31.02359584.393.12Williamson County, TX3.75
    76.98168889.416.70Winnebago County, IL8.05
    35.79421284.723.49Worcester County, MA4.11
    58.42238305.623.87York County, PA4.74

    Table 3.2. All counties with a rate, 2015 to 2021

    Across all 1,206 counties with a published rate the rate is 4.0 in the least deprived tenth and 8.8 in the most deprived

    Births-weighted infant deaths per 1,000 by decile of county deprivation rank, counties with at least 20 infant deaths, County Health Rankings, 2015 to 2021

    conf_highconf_lowdecileestimaten
    4.193.8314.006,629,995
    5.324.8825.114,124,889
    5.975.5135.783,070,833
    6.345.8646.092,816,097
    7.066.3756.722,100,337
    7.346.7067.051,871,135
    8.127.1277.651,376,448
    7.966.7387.38935,698
    7.926.4997.24748,936
    9.468.05108.77467,875

    Note: The counties are the 240 of 261 named counties (at least 250,000 residents) with a published death count in every year; they hold 62.3% of births in the United States. The other 21 named counties have a withheld year (44 withheld county-years in all, each of 1 to 9 deaths) and are left out whole, not pooled over their published years.

    Note: A county's deprivation rank is the population-weighted mean of the Area Deprivation Index national ranks of its census tracts (1 is least deprived, 100 most), weighted by 2019-2023 tract population. Quartiles hold equal numbers of counties, so the most deprived quarter is relative to large counties and not to the nation.

    Note: Quartile means are births-weighted. Intervals are 95% intervals from a bootstrap over counties (replicates and seed in the methods note).

    Note: The second tab uses County Health Rankings rates for counties with at least 20 infant deaths in 2015 to 2021, so it leaves out the smallest counties, and its deciles are deciles of the counties that publish.

    Note: Across all the counties in the second tab the rate is 5.7 per 1,000.

    Source: CDC WONDER linked birth and infant death, 2018-2022, and Area Deprivation Index 2023; crude rates from full counts, births-weighted (population-weighted); second tab: County Health Rankings 2024, 2015-2021

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_by_deprivation.json

    Table 4. The rise with county deprivation holds within states and for births to white mothers and to Black mothers, at 0.63 deaths per 1,000 for each 10-point step across all births

    Change in infant deaths per 1,000 for each 10-point rise in county deprivation rank (births-weighted slope) with 95% intervals, counties of 250,000 residents or more

    conf_highconf_lowgrouplabelnslope
    0.7150.544All birthsAll births, 2018 to 2022 (240 counties)2400.631
    0.8400.467All birthsAll births, 2018 to 2022, within states (44 states)2400.624
    0.7090.518All birthsAll births, 2018 and 2019 (240 counties)2400.619
    0.4400.289WhiteWhite mothers, 2018 and 2019 (203 counties)2030.362
    1.010.617BlackBlack mothers, 2018 and 2019 (115 counties)1150.817

    Note: The slope is the births-weighted regression slope of the county rate on the county deprivation rank, multiplied by ten. Intervals come from a bootstrap over counties, except the within-states row, which resamples whole states because the fixed effects pool counties within a state.

    Note: Race rows use WONDER's single-race groups of any ethnicity and the 240 counties, restricted to the counties that publish the group in both 2018 and 2019: 203 counties for white mothers (93.9% of their births in the counties used) and 115 for Black mothers (82.5%).

    Note: Counties with a higher deprivation rank also have a larger share of births to Black mothers, 11.1% of births in the least deprived quartile and 31.1% in the most deprived (2018 and 2019), so the slope for all births mixes the rise within each group with the shift in the mix of mothers. A county slope describes places, not individual mothers.

    Source: CDC WONDER linked birth and infant death, 2018-2022 (mother's race 2018-2019), and Area Deprivation Index 2023; crude rates from full counts, births-weighted (population-weighted)

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_gradient_checks.json

    Table 5. Infant mortality in 2018 and 2019 was 10.3 per 1,000 for Black mothers and 4.7 for white mothers, a ratio of 2.2

    Infant deaths per 1,000 by mother's single race, any ethnicity, United States, 2018 and 2019, with 95% intervals

    conf_highconf_lowlabelnracerate
    5.685.57All mothers7,539,252All5.63
    10.4910.14Black (any ethnicity)1,255,629Black10.32
    4.784.66White (any ethnicity)5,617,093White4.72
    4.083.74Asian or Pacific Islander (any ethnicity)524,395Asian3.91

    Note: WONDER counts mothers by single race and includes Hispanic mothers in each group, so the white group here is not the non-Hispanic white group of County Health Rankings. Mother's race is reported in the linked file only for 2018 and 2019.

    Note: A state-year cell with fewer than 10 deaths is withheld (1 to 9 deaths) and leaves both deaths and births. The withheld cells hold 1.0% of births to Black mothers, 0.1% of births to white mothers and 6.7% of births to Asian or Pacific Islander mothers.

    Note: For American Indian or Alaska Native mothers WONDER withholds 66 of 102 state-year cells and the published cells hold only 65.6% of their births, so a pooled rate would describe the states with the most deaths. No rate is shown.

    Note: Intervals are gamma or normal intervals on the death counts; they treat deaths as independent and leave out differences between states.

    Source: CDC WONDER linked birth and infant death, 2018-2019, mother's race (crude rates from full counts)

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_by_race.json

    Table 6. Black mothers' infants died at a higher rate than white mothers' in all 36 states that publish both, by a median ratio of 2.1

    Infant deaths per 1,000 by mother's single race, any ethnicity, 36 states, 2018 and 2019, with 95% intervals, ordered by the Black-white difference

    blackhi_bhi_wlo_blo_wn_bn_wstatewhite
    11.6714.624.789.182.666,42913,325Delaware3.60
    12.7313.795.0211.684.3544,064163,307Michigan4.68
    12.6614.455.4110.874.5615,162103,924Wisconsin4.98
    12.2916.085.359.214.054,31242,773Nebraska4.70
    12.9713.965.8611.975.2250,431208,964Ohio5.54
    12.1313.095.1911.184.6051,108213,812Illinois4.90
    11.7212.835.2410.614.2536,44473,958South Carolina4.75
    12.1515.235.899.564.746,17362,047Kansas5.32
    12.6914.836.7610.565.6310,71373,285Oklahoma6.19
    11.9313.076.0310.785.1834,960121,143Tennessee5.60
    11.1611.975.3910.344.6964,533157,420North Carolina5.04
    10.6311.254.8110.014.34106,859317,717Florida4.58
    10.4113.254.928.053.906,33865,737Iowa4.41
    10.6411.305.369.974.6393,071145,932Georgia5
    10.6011.535.299.684.6847,243207,572Pennsylvania4.99
    10.9912.066.169.925.1036,95376,765Alabama5.63
    11.4713.186.819.765.5015,08255,070Arkansas6.16
    9.3410.204.488.483.6048,40480,981Maryland4.04
    9.4311.174.497.693.8011,984131,533Washington4.14
    9.7710.3659.174.65105,253604,692Texas4.83
    10.3711.665.889.075.0323,828116,241Missouri5.45
    8.119.063.537.162.9434,767141,428New Jersey3.23
    10.8211.766.549.885.3846,86868,003Louisiana5.96
    8.639.984.297.283.5218,199101,548Minnesota3.91
    10.6411.986.429.315.5922,926134,146Indiana6.01
    9.0613.095.776.023.613,09216,093Rhode Island4.60
    9.1810.065.178.304.4345,536133,860Virginia4.80
    7.968.563.817.373.3887,384307,616New York3.60
    10.9912.137.459.865.8532,56139,548Mississippi6.65
    9.3311.135.797.534.5511,04251,823Nevada5.17
    9.2010.975.477.434.7011,303132,097Arizona5.09
    8.168.894.217.433.9058,843677,920California4.06
    910.745.507.264.5811,44392,669Kentucky5.04
    7.669.464.286.123.2311,23152,490Connecticut3.75
    8.2510.424.976.434.178,488109,155Colorado4.57
    6.837.973.905.683.1820,073104,559Massachusetts3.54

    Note: Only states that publish infant deaths for both groups in both years appear; they hold 98.0% of births to Black mothers. A state-year cell of 1 to 9 deaths is withheld, and a state is shown only when no cell of either group is withheld, so states with few Black births are absent.

    Note: WONDER counts mothers by single race and includes Hispanic mothers in each group. Intervals are gamma or normal intervals on the death counts and leave out differences between counties within a state.

    Source: CDC WONDER linked birth and infant death, 2018-2019, mother's race (crude rates from full counts)

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_black_white_states.json

    Table 7. Neonatal deaths made up 68.7% of infant deaths in the 14 counties that publish every age group, and both rates are higher where deprivation is higher

    Infant deaths per 1,000 by age at death, 14 counties of 250,000 residents or more, 2018 to 2022, ordered from the least to the most deprived county rank

    ageconf_highconf_lowcountynrate
    Neonatal (under 28 days)2.692.21Orange County, CA (rank 11)163,4372.45
    Postneonatal (28 to 364 days)0.8800.610Orange County, CA (rank 11)163,4370.750
    Neonatal (under 28 days)2.902.44San Diego County, CA (rank 14)190,7652.67
    Postneonatal (28 to 364 days)1.060.790San Diego County, CA (rank 14)190,7650.920
    Neonatal (under 28 days)2.822.53Los Angeles County, CA (rank 14)507,6272.67
    Postneonatal (28 to 364 days)1.301.11Los Angeles County, CA (rank 14)507,6271.20
    Neonatal (under 28 days)2.732.18Queens County, NY (rank 16)127,4982.45
    Postneonatal (28 to 364 days)1.421.03Queens County, NY (rank 16)127,4981.22
    Neonatal (under 28 days)4.273.61San Bernardino County, CA (rank 32)137,2563.94
    Postneonatal (28 to 364 days)1.711.30San Bernardino County, CA (rank 32)137,2561.51
    Neonatal (under 28 days)3.883.41Maricopa County, AZ (rank 36)253,4343.65
    Postneonatal (28 to 364 days)1.921.59Maricopa County, AZ (rank 36)253,4341.76
    Neonatal (under 28 days)3.562.98Miami-Dade County, FL (rank 37)146,8493.27
    Postneonatal (28 to 364 days)1.681.29Miami-Dade County, FL (rank 37)146,8491.48
    Neonatal (under 28 days)4.353.88Cook County, IL (rank 47)282,9784.11
    Postneonatal (28 to 364 days)2.031.71Cook County, IL (rank 47)282,9781.87
    Neonatal (under 28 days)4.343.66Tarrant County, TX (rank 49)136,2534
    Postneonatal (28 to 364 days)2.091.63Tarrant County, TX (rank 49)136,2531.86
    Neonatal (under 28 days)4.624.02Dallas County, TX (rank 52)184,6354.32
    Postneonatal (28 to 364 days)2.201.79Dallas County, TX (rank 52)184,6351.99
    Neonatal (under 28 days)5.664.71Franklin County, OH (rank 55)89,2645.19
    Postneonatal (28 to 364 days)2.652.01Franklin County, OH (rank 55)89,2642.33
    Neonatal (under 28 days)3.913.50Harris County, TX (rank 56)326,5383.71
    Postneonatal (28 to 364 days)2.091.78Harris County, TX (rank 56)326,5381.94
    Neonatal (under 28 days)4.663.95Bexar County, TX (rank 59)130,0374.31
    Postneonatal (28 to 364 days)2.031.57Bexar County, TX (rank 59)130,0371.80
    Neonatal (under 28 days)6.655.72Wayne County, MI (rank 73)109,6976.18
    Postneonatal (28 to 364 days)3.793.10Wayne County, MI (rank 73)109,6973.45

    Note: WONDER withholds 4,328 of 6,525 county-year-age cells in the named counties (1 to 9 deaths each), so only 14 counties publish every age group in every year: among the largest counties, holding 23.6% of births in the named counties. Counties with any withheld cell are left out whole; no group is summed from published cells alone and nothing is derived from totals.

    Note: The row label gives the county deprivation rank (1 least deprived, 100 most). WONDER weights infant deaths, so the age groups can differ from a county's total by rounding.

    Note: Intervals are gamma or normal intervals on each county's death count; they treat deaths as independent.

    Source: CDC WONDER linked birth and infant death, 2018-2022, by age at death; crude rates from full counts

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/imr_age_at_death.json

    Table 8. Infant mortality is steadily worse toward the more deprived end under the ADI and under each of the three other rankings

    Infant deaths per 1,000 live births by tenth of counties ranked four ways, over the 1,206 counties that have all four rankings

    binconf_highconf_lowestimaten_unitsranking
    14.213.844.01120Area Deprivation Index
    25.284.855.07121Area Deprivation Index
    35.985.515.78120Area Deprivation Index
    46.325.816.06121Area Deprivation Index
    56.966.356.65121Area Deprivation Index
    67.446.797.14120Area Deprivation Index
    78.117.107.64121Area Deprivation Index
    87.986.787.41120Area Deprivation Index
    97.866.477.21121Area Deprivation Index
    109.397.988.68121Area Deprivation Index
    14.213.824.01120Standardized index
    25.184.444.80121Standardized index
    35.775.255.50120Standardized index
    46.334.995.61121Standardized index
    56.515.566.02121Standardized index
    66.935.786.33120Standardized index
    77.616.907.28121Standardized index
    88.307.187.72120Standardized index
    98.096.657.32121Standardized index
    108.356.136.95121Standardized index
    14.113.723.91120Median household income
    25.274.564.88121Median household income
    35.855.105.50120Median household income
    46.265.786.02121Median household income
    56.585.826.19121Median household income
    67.396.627.02120Median household income
    77.816.607.25121Median household income
    87.896.767.38120Median household income
    98.306.667.49121Median household income
    109.448.558.99121Median household income
    14.614.074.33120Bachelor's degree share
    25.434.574.98121Bachelor's degree share
    36.125.405.76120Bachelor's degree share
    46.795.315.99121Bachelor's degree share
    56.435.846.12121Bachelor's degree share
    67.415.686.49120Bachelor's degree share
    77.196.356.70121Bachelor's degree share
    87.146.056.58120Bachelor's degree share
    97.546.557.00121Bachelor's degree share
    108.477.187.76121Bachelor's degree share

    Note: Least and most deprived tenth: ADI 4.0 and 8.7, rank correlation +0.95; standardized index 4.0 and 7.0, +0.92; median household income 3.9 and 9.0, +1.00; bachelor's degree share 4.3 and 7.8, +0.99.

    Note: The standardized index applies the ADI's coefficients to its measures after standardizing each one, so home value and income carry less weight than in the ADI. Income and degree share are single census measures, each ranked from the highest value to the lowest.

    Source: County Health Rankings 2024, infant deaths and live births in 2015-2021, and Area Deprivation Index 2023; crude rates from full counts, births-weighted (population-weighted); ADI 2023 and ACS 2019-2023 tract tables (B19013, B15003 and the 15 rebuilt ADI measures)

    Data: vishalsingh.org/zipcode/report/infant-mortality/figures/alt_rankings.json

    All estimates

    Every fact in facts.json (111), sorted by id. The same values as JSON: facts.json.

    Fact idValueUnitEstimandPopulationPeriodIntervalnWeightsSourceNote
    adi_above_pop_share3.3%percent of residentsshare of residents living in counties ranked above the highest county used, 2019-2023 tract populationresidents of the 50 states and DC2019-20232019-2023 tract populationArea Deprivation Index
    adi_max_used84national percentile rank (1 least deprived, 100 most)highest county deprivation rank among the counties usedthe counties used2019-2023 tract population weights240 counties2019-2023 tract populationArea Deprivation Index
    adi_min_used3national percentile rank (1 least deprived, 100 most)lowest county deprivation rank among the counties usedthe counties used2019-2023 tract population weights240 counties2019-2023 tract populationArea Deprivation Index
    age_births_share23.6%percent of live birthsshare of births in the counties shownlive births in the named counties2018 to 2022none (full count)CDC WONDER linked birth and infant death
    age_cells6,525county-year-age cellscount of cellsnamed counties, five age groups, 2018 to 2022infant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    age_cells_withheld4,328withheld cellscount of cells with 1 to 9 infant deaths, which WONDER withholdsnamed counties, five age groups, 2018 to 2022infant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    age_counties14countiescount of countiesnamed counties that publish all five age groups in every year 2018 to 2022infant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    aian_cells102state-year cellscount of state-year cellsAmerican Indian or Alaska Native mothers (single race, any ethnicity) in 50 states and DCinfant deaths and live births in 2018 and 2019none (full count)CDC WONDER linked birth and infant death
    aian_published_share65.6%percent of live birthsshare of births in state-years whose deaths WONDER publisheslive births to American Indian or Alaska Native mothers (single race, any ethnicity)2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    aian_withheld_cells66withheld state-year cellscount of state-year cells with 1 to 9 infant deaths, which WONDER withholdsAmerican Indian or Alaska Native mothers (single race, any ethnicity) in 50 states and DCinfant deaths and live births in 2018 and 2019none (full count)CDC WONDER linked birth and infant death
    alt_adi_least4.0Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe least deprived tenth of counties ranked by Area Deprivation Index, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 3.8 to 4.2120 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_adi_most8.7Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe most deprived tenth of counties ranked by Area Deprivation Index, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 8.0 to 9.4121 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_adi_rho+0.95rank correlationSpearman rank correlation between bin order and bin mean, each bin counted oncethe bins of counties ranked by Area Deprivation Indexinfant deaths and live births in 2015 to 2021each bin counted onceCounty Health Rankings
    alt_degree_least4.3Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe least deprived tenth of counties ranked by Bachelor's degree share, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 4.1 to 4.6120 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_degree_most7.8Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe most deprived tenth of counties ranked by Bachelor's degree share, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 7.2 to 8.5121 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_degree_rho+0.99rank correlationSpearman rank correlation between bin order and bin mean, each bin counted oncethe bins of counties ranked by Bachelor's degree shareinfant deaths and live births in 2015 to 2021each bin counted onceCounty Health Rankings
    alt_income_least3.9Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe least deprived tenth of counties ranked by Median household income, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 3.7 to 4.1120 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_income_most9.0Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe most deprived tenth of counties ranked by Median household income, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 8.5 to 9.4121 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_income_rho+1.00rank correlationSpearman rank correlation between bin order and bin mean, each bin counted oncethe bins of counties ranked by Median household incomeinfant deaths and live births in 2015 to 2021each bin counted onceCounty Health Rankings
    alt_n_places1,206countiescount of counties in the common sample of the ranking comparisoncounties with the outcome and all four rankingsinfant deaths and live births in 2015 to 2021none (full count)County Health Rankings
    alt_rho_cut0.9absolute rank correlationthreshold between a steady and an uneven gradientthe rule for changed gradients (docs/RANKING_SWITCH_RULE.md)infant deaths and live births in 2015 to 2021none (a fixed rule)County Health Rankings
    alt_rho_margin0.1absolute rank correlationsmallest move in the rank correlation that counts as a change of shapethe rule for changed gradients (docs/RANKING_SWITCH_RULE.md)infant deaths and live births in 2015 to 2021none (a fixed rule)County Health Rankings
    alt_std_least4.0Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe least deprived tenth of counties ranked by Standardized index, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 3.8 to 4.2120 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_std_most7.0Infant deaths per 1,000 live birthsbirths-weighted mean of county rates; 95% intervals from a bootstrap over countiesthe most deprived tenth of counties ranked by Standardized index, among the counties with all four rankingsinfant deaths and live births in 2015 to 202195% CI 6.1 to 8.3121 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    alt_std_rho+0.92rank correlationSpearman rank correlation between bin order and bin mean, each bin counted oncethe bins of counties ranked by Standardized indexinfant deaths and live births in 2015 to 2021each bin counted onceCounty Health Rankings
    asian_left_out_share6.7%percent of live birthsshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthslive births to Asian or Pacific Islander mothers (single race, any ethnicity) in the United States2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    births_left_out_share2.6%percent of live birthsshare of births in the counties left out because a year is withheldlive births in the named counties2018 to 2022none (full count)CDC WONDER linked birth and infant death
    births_share_used62.3%percent of live births in the United Statesshare of births in the counties usedlive births in the 50 states and DC2018 to 202218,484,949 birthsnone (full count)CDC WONDER linked birth and infant death
    births_total18.5 millionlive birthscount of live birthslive births in the 50 states and DC2018 to 202218,484,949 birthsnone (full count)CDC WONDER linked birth and infant death
    black_left_out_share1.0%percent of live birthsshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthslive births to Black mothers (single race, any ethnicity) in the United States2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    black_share_q111.1%percent of live birthsshare of births to Black mothers (single race, any ethnicity) over all births, in the county-years where WONDER publishes the group's births; a county-year with no published count leaves both the numerator and the denominatorlive births in the least deprived quarter of the counties used, by county deprivation rank2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    black_share_q431.1%percent of live birthsshare of births to Black mothers (single race, any ethnicity) over all births, in the county-years where WONDER publishes the group's births; a county-year with no published count leaves both the numerator and the denominatorlive births in the most deprived quarter of the counties used, by county deprivation rank2018 and 2019none (full counts of births)CDC WONDER linked birth and infant deathWebb County, TX has no published count of births to Black mothers in 2 county-years, so those county-years are left out. Counting them as zero would give 30.7% for this quarter.
    bw_black_births_share98.0%percent of live birthsshare of those births in the states shownlive births to Black mothers (single race, any ethnicity) in the United States2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    bw_ratio_high3.2ratio of ratesratio of crude rates in the state with the largest ratio, log-normal interval on the two death countslive births in Delaware, Black mothers over white mothers (single race, any ethnicity)2018 and 201995% CI 2.3 to 4.7123 infant deathsnone (crude rates from counts)CDC WONDER linked birth and infant death
    bw_ratio_low1.7ratio of ratesratio of crude rates in the state with the smallest ratio, log-normal interval on the two death countslive births in Mississippi, Black mothers over white mothers (single race, any ethnicity)2018 and 201995% CI 1.4 to 1.9621 infant deathsnone (crude rates from counts)CDC WONDER linked birth and infant death
    bw_ratio_median2.1ratio of ratesmedian of the state ratioslive births in the states shown, Black mothers over white mothers (single race, any ethnicity)2018 and 201936 statesnone (each state counts once)CDC WONDER linked birth and infant death
    bw_states36statescount of statesstates that publish infant deaths for both Black and white mothers in both 2018 and 2019infant deaths and live births in 2018 and 2019none (full count)CDC WONDER linked birth and infant death
    chr_all_corr0.76correlation coefficientbirths-weighted correlation of the county rate with county deprivation rank, county-cluster bootstrap intervallive births in counties with a County Health Rankings rateinfant deaths and live births in 2015 to 202195% CI 0.71 to 0.801,206 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    chr_all_d14.0infant deaths per 1,000 live birthsbirths-weighted mean of county rates, bootstrap interval over countieslive births in the least deprived tenth of counties with a County Health Rankings rateinfant deaths and live births in 2015 to 202195% CI 3.8 to 4.2120 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    chr_all_d108.8infant deaths per 1,000 live birthsbirths-weighted mean of county rates, bootstrap interval over countieslive births in the most deprived tenth of counties with a County Health Rankings rateinfant deaths and live births in 2015 to 202195% CI 8.1 to 9.5121 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    chr_counties1,206countiescount of counties with at least 20 infant deaths in the periodcounties and county equivalents with a County Health Rankings infant mortality rate and an ADIinfant deaths and live births in 2015 to 2021none (full count)County Health Rankings
    chr_lbd_corr0.980correlation coefficientbirths-weighted correlation between the county rate in WONDER and in County Health Rankings, county-cluster bootstrap intervallive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022WONDER 2018 to 2022 and County Health Rankings 2015 to 202195% CI 0.974 to 0.985240 countiesWONDER births in each countyCounty Health Rankings
    counties_above_adi_max712countiescount of counties whose rank is above the highest rank among the counties usedcounties and county equivalents in the 50 states and DC with a deprivation rank2019-2023 tract population weights3,128 countiesnone (full count)Area Deprivation Index
    counties_left_out21countiescount of counties left out of the county ratesnamed counties with a withheld death count in at least one year 2018 to 2022infant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    counties_named261countiescount of counties (two identifiers with no births are left out)counties that WONDER linked birth and infant death names individually and that have birthsinfant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    counties_not_mapped1,937countiescount of counties with no County Health Rankings ratecounties and county equivalents on the map (50 states and DC)infant deaths and live births in 2015 to 2021none (full count)County Health Rankings
    counties_used240countiescount of countiesnamed counties with a published death count in every year 2018 to 2022infant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    deaths_total102,503infant deathscount of infant deaths (WONDER weights deaths, so the count can differ from the unweighted number of records by rounding)infants born in the 50 states and DC2018 to 2022none (full count)CDC WONDER linked birth and infant death
    first_day_share42.3%percent of infant deathspooled share that are deaths in the first 24 hours, bootstrap interval over countiesinfant deaths in the 14 counties that publish all five age groups2018 to 202295% CI 40.5% to 44.2%14 countiesinfant deaths in each countyCDC WONDER linked birth and infant death
    imr_20215.44infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in the 50 states and DC202195% CI 5.36 to 5.5119,927 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_adi_corr0.80correlation coefficientbirths-weighted correlation of the county rate with county deprivation rank, county-cluster bootstrap intervallive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 20222018 to 202295% CI 0.73 to 0.86240 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_all_18195.6infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in the 50 states and DC2018 and 201995% CI 5.6 to 5.742,421 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_asian3.9infant deaths per 1,000 live birthscrude rate from state counts, normal intervallive births to Asian or Pacific Islander mothers (single race, any ethnicity) in the United States, states with a published count2018 and 201995% CI 3.7 to 4.12,051 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_black10.3infant deaths per 1,000 live birthscrude rate from state counts, normal intervallive births to Black mothers (single race, any ethnicity) in the United States, states with a published count2018 and 201995% CI 10.1 to 10.512,953 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_midwest6.1infant deaths per 1,000 live birthspooled crude rate over the region's states (12 states), bootstrap interval over those stateslive births in the Midwest Census region2018 to 202295% CI 5.5 to 6.512 statesbirths in each stateCDC WONDER linked birth and infant death
    imr_natl5.5infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in the 50 states and DC2018 to 202295% CI 5.5 to 5.6102,503 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_northeast4.5infant deaths per 1,000 live birthspooled crude rate over the region's states (9 states), bootstrap interval over those stateslive births in the Northeast Census region2018 to 202295% CI 3.9 to 5.29 statesbirths in each stateCDC WONDER linked birth and infant death
    imr_q13.9infant deaths per 1,000 live birthsbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countieslive births in the least deprived quarter of the counties used, by county deprivation rank2018 to 202295% CI 3.7 to 4.160 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_q47.2infant deaths per 1,000 live birthsbirths-weighted mean of county rates (the pooled rate), bootstrap interval over countieslive births in the most deprived quarter of the counties used, by county deprivation rank2018 to 202295% CI 6.7 to 7.660 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_q_diff3.3infant deaths per 1,000 live birthsdifference of two pooled rates, bootstrap interval over counties with shared drawslive births in the counties used, most deprived quarter minus least deprived quarter2018 to 202295% CI 2.8 to 3.8240 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_q_ratio1.9ratio of ratesratio of two pooled rates, bootstrap interval over counties with shared drawslive births in the counties used, most deprived quarter over least deprived quarter2018 to 202295% CI 1.7 to 2.0240 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_race_gap5.6infant deaths per 1,000 live birthsdifference of crude rates, normal interval on the two death countslive births in the United States, Black mothers minus white mothers (single race, any ethnicity)2018 and 201995% CI 5.4 to 5.839,469 infant deathsnone (crude rates from counts)CDC WONDER linked birth and infant death
    imr_race_ratio2.2ratio of ratesratio of crude rates, log-normal interval on the two death countslive births in the United States, Black mothers over white mothers (single race, any ethnicity)2018 and 201995% CI 2.1 to 2.239,469 infant deathsnone (crude rates from counts)CDC WONDER linked birth and infant death
    imr_rest5.1infant deaths per 1,000 live birthspooled crude rate over the states of the group (34 states), bootstrap interval over those stateslive births outside the Census South region2018 to 202295% CI 4.6 to 5.734 statesbirths in each stateCDC WONDER linked birth and infant death
    imr_slope_1819_per_100.62infant deaths per 1,000 live births for each ten points of county deprivation rankbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervallive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 2022, deaths and births in 2018 and 2019 only2018 and 201995% CI 0.52 to 0.71240 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_slope_black_per_100.82infant deaths per 1,000 live births for each ten points of county deprivation rankbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervallive births to Black mothers (single race, any ethnicity) in the counties used that publish the group in both years2018 and 201995% CI 0.62 to 1.01115 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_slope_fe_per_100.62infant deaths per 1,000 live births for each ten points of county deprivation rankbirths-weighted slope of the county rate on county deprivation rank with state fixed effects, bootstrap interval over stateslive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 20222018 to 202295% CI 0.47 to 0.8444 statesbirths in each countyCDC WONDER linked birth and infant death
    imr_slope_per_100.63infant deaths per 1,000 live births for each ten points of county deprivation rankbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervallive births in the counties of 250,000 residents or more that publish infant deaths in every year 2018 to 20222018 to 202295% CI 0.54 to 0.71240 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_slope_white_per_100.36infant deaths per 1,000 live births for each ten points of county deprivation rankbirths-weighted slope of the county rate on county deprivation rank, county-cluster bootstrap intervallive births to white mothers (single race, any ethnicity) in the counties used that publish the group in both years2018 and 201995% CI 0.29 to 0.44203 countiesbirths in each countyCDC WONDER linked birth and infant death
    imr_south6.3infant deaths per 1,000 live birthspooled crude rate over the states of the group (17 states), bootstrap interval over those stateslive births in the Census South region (16 states and DC)2018 to 202295% CI 5.9 to 6.917 statesbirths in each stateCDC WONDER linked birth and infant death
    imr_state_high8.7infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in Mississippi2018 to 202295% CI 8.3 to 9.21,564 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_state_low3.7infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in Massachusetts2018 to 202295% CI 3.5 to 3.91,260 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_state_low_nh3.7infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in New Hampshire2018 to 202295% CI 3.2 to 4.2224 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_state_ratio2.4ratio of ratesratio of Mississippi's crude rate to Massachusetts's, log-normal interval on the two death countslive births in Mississippi and in Massachusetts2018 to 202295% CI 2.2 to 2.62,824 infant deathsnone (crude rates from counts)CDC WONDER linked birth and infant death
    imr_west4.6infant deaths per 1,000 live birthspooled crude rate over the region's states (13 states), bootstrap interval over those stateslive births in the West Census region2018 to 202295% CI 4.3 to 5.313 statesbirths in each stateCDC WONDER linked birth and infant death
    imr_white4.7infant deaths per 1,000 live birthscrude rate from state counts, normal intervallive births to white mothers (single race, any ethnicity) in the United States, states with a published count2018 and 201995% CI 4.7 to 4.826,516 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_year_high5.7infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in the 50 states and DC201895% CI 5.6 to 5.721,496 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    imr_year_low5.4infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births in the 50 states and DC202095% CI 5.3 to 5.519,576 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    jurisdictions51jurisdictionscount of states and DC in the state filesthe 50 states and the District of Columbiainfant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    lbd_county_threshold250,000residentspopulation size at which WONDER names a county in the linked file (a definition)counties that CDC WONDER linked birth and infant death names individuallyinfant deaths and live births in 2018 to 2022none (definition)CDC WONDER linked birth and infant death
    lbd_withheld_cells44withheld county-yearscount of county-years with 1 to 9 infant deaths, which WONDER withholdscounty-year rows of the named countiesinfant deaths and live births in 2018 to 2022none (full count)CDC WONDER linked birth and infant death
    lbd_withheld_max_share0.6%percent of infant deathslargest share of deaths the withheld county-years could hold: 9 deaths in each withheld county-year, over published deaths plus that limitinfant deaths in the named counties2018 to 2022none (an upper limit from the cell count)CDC WONDER linked birth and infant death
    map_floor_deaths20infant deathsfewest infant deaths in the period for which County Health Rankings publishes a county rate, which is also the book's map floor (a definition)counties on the mapinfant deaths and live births in 2015 to 2021none (definition)County Health Rankings
    map_key_high10.6infant deaths per 1,000 live birthsninety-fifth percentile of the mapped county rates, the high end of the map key (counties beyond it take the end color)mapped countiesinfant deaths and live births in 2015 to 20211,206 countiesnone (each county counts once)County Health Rankings
    map_key_low3.7infant deaths per 1,000 live birthsfifth percentile of the mapped county rates, the low end of the map key (counties beyond it take the end color)mapped countiesinfant deaths and live births in 2015 to 20211,206 countiesnone (each county counts once)County Health Rankings
    map_ms_top25countiescount of those counties in Mississippimapped counties in the highest tenth of infant mortality ratesinfant deaths and live births in 2015 to 2021121 countiesnone (each county counts once)County Health Rankings
    map_south_all_share49.3%percent of countiesshare of mapped counties in the Census South region (16 states and DC)all mapped countiesinfant deaths and live births in 2015 to 20211,206 countiesnone (each county counts once)County Health Rankings
    map_south_top_share85.1%percent of countiesshare of those counties in the Census South region (16 states and DC)mapped counties in the highest tenth of infant mortality ratesinfant deaths and live births in 2015 to 2021121 countiesnone (each county counts once)County Health Rankings
    neo_rate3.6infant deaths per 1,000 live birthspooled neonatal (under 28 days) death rate, bootstrap interval over countieslive births in the 14 counties that publish all five age groups2018 to 202295% CI 3.1 to 4.114 countiesbirths in each countyCDC WONDER linked birth and infant death
    neo_ratio_halves1.5ratio of ratesratio of pooled neonatal death rates, bootstrap interval over counties with shared drawslive births in the 14 counties that publish all five age groups, the counties above the median deprivation rank over those below it2018 to 202295% CI 1.2 to 1.814 countiesbirths in each countyCDC WONDER linked birth and infant death
    neo_share68.7%percent of infant deathspooled share that are neonatal deaths (under 28 days), bootstrap interval over countiesinfant deaths in the 14 counties that publish all five age groups2018 to 202295% CI 67.4% to 70.2%14 countiesinfant deaths in each countyCDC WONDER linked birth and infant death
    neonatal_cutoff_days28days of ageage below which an infant death is neonatal; from this age to the first birthday it is postneonatal (a definition)infantsall years (a definition)none (definition)CDC WONDER linked birth and infant death
    per_10001,000live birthsthe denominator of an infant mortality rate (a definition)all live birthsall years (a definition)none (definition)CDC WONDER linked birth and infant death
    post_rate1.6infant deaths per 1,000 live birthspooled postneonatal (28 to 364 days) death rate, bootstrap interval over countieslive births in the 14 counties that publish all five age groups2018 to 202295% CI 1.4 to 1.914 countiesbirths in each countyCDC WONDER linked birth and infant death
    post_ratio_halves1.6ratio of ratesratio of pooled postneonatal death rates, bootstrap interval over counties with shared drawslive births in the 14 counties that publish all five age groups, the counties above the median deprivation rank over those below it2018 to 202295% CI 1.3 to 2.114 countiesbirths in each countyCDC WONDER linked birth and infant death
    race_births_share_black82.5%percent of live birthsshare of those births in counties that publish the group in both yearslive births to Black mothers in the counties used2018 and 2019none (full count)CDC WONDER linked birth and infant death
    race_births_share_white93.9%percent of live birthsshare of those births in counties that publish the group in both yearslive births to white mothers in the counties used2018 and 2019none (full count)CDC WONDER linked birth and infant death
    race_counties_black115countiescount of countiescounties used that publish Black infant deaths in both 2018 and 2019infant deaths and live births in 2018 and 2019none (full count)CDC WONDER linked birth and infant death
    race_counties_white203countiescount of countiescounties used that publish white infant deaths in both 2018 and 2019infant deaths and live births in 2018 and 2019none (full count)CDC WONDER linked birth and infant death
    rank_step10points of county deprivation rankthe step in the county deprivation rank for which a slope is reported (a definition)countiesall years (a definition)none (definition)Area Deprivation Index
    south_in_top7stateshighest-rate states in the Census South region (16 states and DC)the ten states with the highest infant mortality rates2018 to 202210 statesnone (each state counts once)CDC WONDER linked birth and infant death
    south_n17jurisdictionsjurisdictions in the Census South region (16 states and DC)the 50 states and DC2018 to 2022none (full count)CDC WONDER linked birth and infant death
    south_rest_ratio1.2ratio of ratesratio of pooled crude rates (17 South states over 34 other states), stratified bootstrap interval that resamples the states of each group separatelylive births in the 50 states and DC, Census South region over the rest2018 to 202295% CI 1.1 to 1.451 states in the two groupsbirths in each stateCDC WONDER linked birth and infant death
    states_above21statesstates whose 95% interval lies above the national ratethe 50 states and DC2018 to 202251 jurisdictionsnone (crude rates from counts)CDC WONDER linked birth and infant death
    states_below16statesstates whose 95% interval lies below the national ratethe 50 states and DC2018 to 202251 jurisdictionsnone (crude rates from counts)CDC WONDER linked birth and infant death
    states_top_n10statesthe number of highest-rate states examined (a definition)the 50 states and DC2018 to 2022none (definition)CDC WONDER linked birth and infant death
    us_imr5.7infant deaths per 1,000 live birthsbirths-weighted mean of county rates over all the deciles, bootstrap interval over countieslive births in all counties with a County Health Rankings rate, ranked by the ADIinfant deaths and live births in 2015 to 202195% CI 5.5 to 5.91,206 countiesbirths in each county (County Health Rankings denominator)County Health Rankings
    white_left_out_share0.1%percent of live birthsshare of births in state-years whose deaths WONDER withholds, which leave both deaths and birthslive births to white mothers (single race, any ethnicity) in the United States2018 and 2019none (full counts of births)CDC WONDER linked birth and infant death
    white_state_high6.7infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births to white mothers (single race, any ethnicity) in Mississippi2018 and 201995% CI 5.8 to 7.5263 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    white_state_low3.2infant deaths per 1,000 live birthscrude rate from the death count, normal intervallive births to white mothers (single race, any ethnicity) in New Jersey2018 and 201995% CI 2.9 to 3.5457 infant deathsnone (crude rate from counts)CDC WONDER linked birth and infant death
    wonder_suppression_floor10infant deathsa cell with fewer deaths than this is withheld (a definition)cells of the WONDER linked birth and infant death filesinfant deaths and live births in 2018 to 2022none (definition)CDC WONDER linked birth and infant death

    Definitions

    Infant mortality rate
    The number of babies who die before their first birthday for every thousand live births.
    Crude rate
    Deaths or births divided by the population, with no adjustment for age. A place with older residents has a higher crude death rate even if health at each age is the same.
    Suppression
    The withholding of a number because the count behind it is too small to publish without risking the identification of a person. A suppressed value is missing, not zero.
    Area Deprivation Index (ADI)
    A score that ranks neighborhoods by income, education, employment and housing conditions drawn from the American Community Survey. In this book a higher national percentile means a more deprived neighborhood.
    Ecological inference
    Drawing conclusions about individuals from data about places or groups. A pattern across counties need not hold for the people inside them.

    Methods

    This chapter compares infant deaths per 1,000 live births across states, counties, groups of mothers by race and ages at death, using CDC WONDER linked birth and infant death records for 2018 to 2022. The rates are crude, with no adjustment for the mother's age or other characteristics. County rates cover only counties that WONDER names (250,000 residents or more) and that publish a death count in every year, so the 21 named counties with a withheld year are left out. Mother's race is reported only for 2018 and 2019, and the county map and the all-county check use County Health Rankings rates for 2015 to 2021, a different source and period.

    What is counted and for which years

    Infant mortality is the number of infant deaths (before the first birthday) per 1,000. Rates are crude: nothing is adjusted for the mother's age or other characteristics.

    Counts come from CDC WONDER linked birth and infant death records, which link death certificates to birth certificates; a death is assigned to the year of death and divided by live births in the same year. WONDER weights infant deaths, so counts can differ from the number of records, and age groups from a total, by rounding.

    State rates pool 2018 to 2022 over the 51 jurisdictions, whose totals have no withheld cell. The 2021 state file reproduces the national rate and the highest and lowest state in the NCHS report for that year (5.44 per 1,000 nationally).

    Figure explained here: Figure 1

    Which counties are included

    County rates cover the counties that WONDER names (250,000 residents or more; WONDER pools every other county in a state into one Unidentified Counties row) and use only counties with a published death count in every year 2018 to 2022: a county-year with 1 to 9 deaths is withheld, a county's published years are its high years, and pooling over them would bias the rate upward. A withheld cell is missing; nothing is derived from totals minus published cells. The 21 named counties with a withheld year are left out whole.

    Figure explained here: Figure 3

    Why mother's race and age at death cover fewer places

    Mother's race comes from the linked file for 2018 and 2019, the only years it is reported, as single race of any ethnicity; a state-year cell of 1 to 9 deaths is withheld and leaves both deaths and births, a group's national rate pools the published state-years, and Black and white rates by state use states that publish both groups in both years. American Indian or Alaska Native mothers are not shown because too few of their state-years are published.

    Age at death uses the county file, in which the five age groups (under 1 hour, 1 to 23 hours, 1 to 6 days, 7 to 27 days, 28 to 364 days) are each withheld below 10 deaths; neonatal is the first four groups and postneonatal the last, and only counties that publish all five groups in every year are used.

    Figures explained here: Figure 5, Figure 6 and Figure 7

    The county map and the all-county check use County Health Rankings

    The county map and the all-county gradient use County Health Rankings 2024, whose infant mortality rate covers 2015 to 2021 and is published only from 20 deaths (window and rule as in the County Health Rankings 2024 technical documentation and the dataset note; as a consistency check, its denominators run about one percent above the 2016 to 2022 births behind its low birthweight measure, as 2015 to 2021 births would).

    Figures explained here: Figure 2 and Figure 4

    How counties are ranked and grouped

    A county's deprivation rank is the population-weighted mean of the Area Deprivation Index national ranks of its census tracts, weighted by 2019-2023 tract population; Connecticut tracts are assigned to the eight legacy counties. Quartiles and deciles hold equal numbers of counties. Quartile and decile means are births-weighted means of county rates (pooled rates).

    Figure explained here: Figure 3

    How uncertainty is measured

    State rates carry gamma (fewer than 100 deaths) or normal (100 or more) intervals on the death count, the NCHS convention. Ratios of two crude rates carry log-normal intervals on the two death counts and differences carry normal intervals.

    Means, differences, ratios, correlations and slopes across counties carry 95% percentile intervals from a bootstrap that resamples whole counties (2,000 replicates, seed 12345); the state fixed-effects slope resamples whole states, and so does each region's pooled rate, within the states of that region; a group needs at least five states, and the Northeast, with nine, has the roughest interval; the ratio of the South to the other states resamples the states of each group separately (seeds 12345 and 12346).

    Four rankings of the same places

    The comparison follows the book's ranking switch rule, fixed on October 28, 2026 before any of these gradients was computed. The main gradient of the chapter is recomputed under four rankings of the same places, with the outcome, period, weights, bins and intervals unchanged: the published ADI; a standardized index that applies the ADI's coefficients to its measures after standardizing each one across tracts; median household income; and the share of adults 25 and older with a bachelor's degree or more. The three alternatives come from ACS tract estimates for 2019 to 2023, the period of the ADI.

    All four rankings use the same places, the 1,206 counties that have the outcome and all four rankings, so the ADI panel can differ slightly from the chapter's main figure. Tracts enter only if they have every input of the standardized index, which leaves out tracts without a median rent, home value or mortgage cost. A county takes the population-weighted mean of the ranks of its common-sample tracts, weighted by 2019-2023 tract population, with Connecticut tracts assigned to the eight legacy counties that County Health Rankings uses.

    A pattern counts as changed when the worse end switches sides, when the two ends differ under one ranking and not the other, or when the rank correlation of bin order and bin mean falls on the other side of 0.9 and moves by at least 0.1.

    Figure explained here: Figure 8

    What these data cannot show

    The county gradient describes the 240 largest counties, which hold 62.3% of births. WONDER pools the rest by state. The County Health Rankings check reaches smaller counties but leaves out those that do not reach 20 deaths in the period, and the counties just above that floor have the least precise rates on the map. The county rates describe counties that publish a figure, which are not a sample of all counties, and the age-at-death figure covers only 14 of them.

    Sources and periods differ, and each is named where it appears. WONDER covers 2018 to 2022 for states and counties and 2018 and 2019 for mother's race, and County Health Rankings covers 2015 to 2021. WONDER's race groups are single races that include Hispanic mothers, so its white group is not the non-Hispanic white group of other sources, and Hispanic origin is not in the files used here. American Indian or Alaska Native mothers are not shown.

    The Area Deprivation Index understates deprivation in high-cost cities (Chapter 1.1, What the deprivation index measures (https://vishalsingh.org/zipcode/anatomy-of-deprivation)) and draws on the American Community Survey for 2019 to 2023, while the deaths are from 2018 to 2022. A county's rank averages over tracts that differ within the county, and it describes no family's circumstances. Patterns across counties and states are patterns of places, not of individual infants, a limit known as ecological inference.

    Finally, the files carry no cause of death, no gestational age or birthweight, and no information on mothers beyond race, so nothing here identifies a mechanism. The rates are crude period rates, and 2020 to 2022 include the pandemic. Intervals for state and race rates treat deaths as independent and leave out differences between places within each rate, while the county figures resample whole counties.

    References

    1. Chen, Alice; Oster, Emily; Williams, Heidi (2016). Why Is Infant Mortality Higher in the United States than in Europe?. American Economic Journal: Economic Policy 8(2): 89-124. doi:10.1257/pol.20140224
    2. Ely, Danielle M.; Driscoll, Anne K. (2023). Infant Mortality in the United States, 2021: Data From the Period Linked Birth/Infant Death File. National Vital Statistics Reports 72(11). doi:10.15620/cdc:131356
    3. Kind, Amy J. H.; Buckingham, William R. (2018). Making Neighborhood-Disadvantage Metrics Accessible: The Neighborhood Atlas. New England Journal of Medicine 378(26): 2456-2458. doi:10.1056/NEJMp1802313

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    0.1.0
    Build script
    book2/chapters/infant-mortality/build.py (sha256 a02fbe8b137224283f0e9dd52c1a4846216f2697c9f9329890e71495d137658c)
    Built on
    2026-10-07
    Site commit
    c2b1ff3309cb4a10833f884da91ac0057a66ad0a

    Inputs

    FileSize (bytes)SHA-256, first 1 MBSHA-256, last 1 MB
    data/analytic/tract_atlas.parquet39,659,92529d5e4d943552d54aeb6ba92aadc939d9bd15bdea553c78357dbd516757be6271e10d1ecf722340f23ee2212d4999a90250f85b65fa89b39e32db06d9472e22e
    data/geo/dim_geo.parquet1,180,92129d5e4d943552d54aeb6ba92aadc939d9bd15bdea553c78357dbd516757be627e58c8c488df54ab3187f5461f179322afdc49c9bd2315404003fe1272eea32c3
    data/raw/acs/deprivation_components_2019_2023/tract.parquet13,197,7935545cde2cbe96a8b56e468d65388248a241aa6bd300d3c9e325d08d3f86b11da5c8ec454d066988b0f1a01aaa6ed34ebfc05d162e01cf9c6bb01f9198cbaff12
    data/staged/adi/adi_atlas_tract2020_2023.parquet798,0785e409bc212ff871def780fa27b4cf8b616d9da420b2b9f6455517eddcd8c1a955e409bc212ff871def780fa27b4cf8b616d9da420b2b9f6455517eddcd8c1a95
    data/staged/crosswalks/ct_tract2020_to_old_county.parquet15,842961ef39f31596ef65fca2c67d5f2f63e533c5dc9b49745d3bb6437844e4b831d961ef39f31596ef65fca2c67d5f2f63e533c5dc9b49745d3bb6437844e4b831d
    data/staged/health/chr_county_2024.parquet8,776,933619795f7ecfec8aff10694b649eaee5e421dbeffbe4be47af4161b51ceefa5cdc69357f1bcf630407bb9716cb445618838999558c019aaaf77d4681b6bf45c56
    data/staged/mortality/wonder_lbd_county_age_2018_2022.parquet44,1113c93255ccfddd6ef6a06b7c2aec1f5a66ad62f3a4a1f342a6f19f67a47bcdfe53c93255ccfddd6ef6a06b7c2aec1f5a66ad62f3a4a1f342a6f19f67a47bcdfe5
    data/staged/mortality/wonder_lbd_county_race_2018_2022.parquet50,622cbe4c336184a835d2d61a2b626c3f4c48455a254ea8ff2a7a6d6eb6fbca700edcbe4c336184a835d2d61a2b626c3f4c48455a254ea8ff2a7a6d6eb6fbca700ed
    data/staged/mortality/wonder_lbd_county_total_2018_2022.parquet29,9038e0f2604f2be86d6d86c2d206fa4486b2479411c88a6bb9b1595f3d945a4e5b88e0f2604f2be86d6d86c2d206fa4486b2479411c88a6bb9b1595f3d945a4e5b8
    data/staged/mortality/wonder_lbd_state_race_2018_2022.parquet16,4619d17fb750f0d7d3e99d48945e1131654951deddcabfa1d520f0cbf3d717ab7109d17fb750f0d7d3e99d48945e1131654951deddcabfa1d520f0cbf3d717ab710
    data/staged/mortality/wonder_lbd_state_total_2018_2022.parquet10,24160c10382f900be2cd9d44fbcef5dcc9c559e857ab644097d2f546253484ac42d60c10382f900be2cd9d44fbcef5dcc9c559e857ab644097d2f546253484ac42d
    data/staged/ses/acs5_tract2020_2019_2023.parquet7,232,4245fe6f730a35225f14d5d8abfc6b9bce58b52e545f309a7eac74f1dae74d7a31c7b4a2475b3852d3f91804716a04566ef8ceadacec2be9fb85f5eb642078efac6
    data/staged/svi/svi_tract2020_2022.parquet17,740,415cb3860d8edc2aaf1f2a02211a58f7a0b80457eb6ad9a37b5ec8abb2d5da9da10e371a4a696d5bed05d54ad7c5b6ca2504508805b847ec415c2322be7f66ec2b2

    Outputs

    FileSHA-256
    facts.json692b8c0a99be5f6003eee48dd12459e7f65edc244298bf9b5c1f6044d810cfc6
    figures/alt_rankings.jsonf65e1e27fd5688264db1374dadbdc45f9ec310c1c979dcb715318361b537b178
    figures/imr_age_at_death.json0b930545b9cbe520881610e4cf9da71c5f80788fcdea214a8a3f4b7404213339
    figures/imr_black_white_states.json21dbd5660b053825d8e216d901282e3837d8eb99f38a9d78026334a33022a045
    figures/imr_by_deprivation.jsonebe5d39824c8881f3b66cf5662e8da7229643c1894815e73029362570c2ff062
    figures/imr_by_race.json5f4a314c27901d8332ce34ad143de499ff41c7ecac5ee5670973aff1b23568f7
    figures/imr_by_state.jsoncc13e7b94a90fe6a337d8a5dcb1e521a6828ad908f5e31c95263a70d1f3bcbe0
    figures/imr_county_map.jsone2ab821b4602e116709c5d01d6cdf5989caff366a4758d79fbddeaf4573ac622
    figures/imr_gradient_checks.json069e6db198ea6885e56ada2d237bcdce8f80558b632aedc4677e82e882d665fd
    meta.jsond8ebd63357145818c218da552fc524ccb8054aeedbcc5b89e9acda517ac8c13c
    public/data/infant-mortality/imr_county_map.json71c917b82e4dbc153c8690b5c6870faa21f8c7a998e3f36fb38057f6cbd963fa
    refs.json9a6c7e9cd1e6cc5e38bee847979896206ef20d8b68fd0af97b3022c93232bdde

    Machine formats