{
  "alt": "County map of the United States shaded by the low-birthweight share of births. Counties with the highest shares are concentrated across the South, and counties in much of the rest of the country have lower shares. Gray hatched counties have no value.",
  "caption": "Counties with higher shares are shaded toward the high end of the key, and gray hatched counties have no value, either because the county had too few low-birthweight births to publish or fell below the map floor; the tooltip gives the reason. The map plots the share of live births under {fact:lbw_cutoff_grams} grams in {fact:counties_mapped} counties.",
  "data": [],
  "id": "lbw_map",
  "notes": [
    "Counties with fewer than 10 low-birthweight births in the period have no rate in County Health Rankings, and counties with fewer than 20 are drawn as no data here, the same floor the book uses for death maps. {fact:counties_not_mapped} counties are not mapped.",
    "The South is the Census South region (16 states and DC). County Health Rankings rates come from the same NCHS birth records as WONDER; across the large counties the two sources correlate at {fact:chr_wonder_corr}.",
    "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, births in 2016-2022 (NCHS natality counts); county rates, population-weighted by births",
  "spec": {
    "fips": "fips",
    "legendLabel": "Births under 2,500 grams (% of live births), 2016 to 2022",
    "payload": "lbw_map.json",
    "scale": {
      "domain": [
        5.7,
        12.6
      ],
      "palette": "seq",
      "type": "sequential"
    },
    "tooltipKeys": [
      "births",
      "conf_low",
      "conf_high"
    ],
    "tooltipLabels": {
      "births": "Live births, 2016 to 2022",
      "conf_high": "Upper limit of the 95% interval",
      "conf_low": "Lower limit of the 95% interval"
    },
    "value": "rate",
    "valueFormat": {
      "digits": 1
    }
  },
  "subtitle": "Share of live births under {fact:lbw_cutoff_grams} grams by county, County Health Rankings 2024, births in 2016 to 2022",
  "title": "Low birthweight is most common in the South, where {fact:south_top_share} of the counties in the highest tenth of shares lie, against {fact:south_all_share} of mapped counties",
  "type": "county-map",
  "width": "full"
}