To determine the least healthy city in every state, 24/7 Wall St. created an index composed of 35 health outcomes and health factors with data from the 2020 County Health Rankings & Roadmaps, a joint program of the Robert Wood Johnson Foundation and the University of Wisconsin Population Health Institute. We calculated composite scores for outcomes and factors separately, then combined the two scores to form a single score that determined the metropolitan statistical area’s rank.
All data used in the index came from the CHR with the exception of 2019 annual unemployment rates for each MSA — these are the most recent annual figures available from the Bureau of Labor Statistics’ Local Area Unemployment Statistics program. For all other CHR measures, county-level data was aggregated to the MSA level using raw values provided at the county level, and measures without raw values by county were calculated using weighted averages based on population distribution within each MSA by county.
We also considered measures from the American Community Survey (ACS) including median household income, poverty and educational attainment rates. These measures were not included in the index.
Values selected for the index were standardized into Z-Scores, which assumes a mean of 0 and a standard deviation of 1. Z-scores are calculated for each index measure by MSA, within each of their respective states. If an MSA spans multiple states, then the city was indexed according to its primary state, as designated by the Census Bureau. Note that four states — Rhode Island, New Hampshire, Vermont, and Delaware — only have one MSA.
Health outcomes with the heaviest weights in the index include the age-adjusted premature mortality rate, the percentage of births with low birthweight, the percentage of adults reporting fair or poor health, and the age-adjusted average number of mentally and physically unhealthy days per month. The premature mortality rate is defined as the number of deaths under the age of 75 per 100,000 people. Unhealthy days are determined by the average number of days out of the month the adult population (18+) self-identifies as being unwell. This is used as an indicator of how chronic disabilities or illnesses (physical and mental) affect members of a particular geography.
Health factors with the heaviest weights in the index include the smoking rate, the 2019 annual unemployment rate, injury mortality, and the child poverty rate. Injury mortality per 100,000 measures the rate at which the total population is killed due to injury, whether intentional (for example suicide), or unintentional (drug overdose, car accidents, accidental suffocation, etc). Air Quality is another health factor and is determined by measuring the average daily density of particulate matter at 2.5 micrograms (or PM2.5 for short).
The remaining measures included in the index, as well as an explanation as to why they were used, can be found at County Health Rankings & Roadmaps.