Table of contents:
Our MissionOur ReportsOur Advisory CommitteesAdvisory CouncilAnnual Report Advisory CommitteeSenior Report Advisory CommitteeHealth of Women and Children Report Advisory CommitteeHealth of Those Who Have Served Report Advisory CommitteeHealth Disparities Report Advisory Committee
Our Model and MethodologyIntroductionRankingsMeasures, Weights and DirectionMeasures Selection and ChangesData SourcesDisparity Measures Methodology
The state health rankings are a composite index of state-level population health measures. Each measure is ranked by the states’ values, with one being the healthiest value and 50 the least healthy value. Ties in value are assigned equal ranks. The states’ values for each measure are then normalized into a z-score using the following formula:
The score indicates the number of standard deviations a state value is above or below the U.S. value. A score with the value of zero indicates a state has the same value as the nation. For measures positively associated with health, states with healthier values than the U.S. have a positive score, while states that perform below the U.S. have a negative score and vice versa for measures negatively associated with health. To prevent an extreme value from exerting excessive influence on the overall state score, the maximum score for a measure is capped at +/- 2.00.
The state health rankings are the ordering of the states according to their overall scores. A state’s overall score is calculated by adding the products of the score for each ranked measure multiplied by its assigned weight and impact (positive or negative) on health. If a state value is not available for a measure in an edition, the value from a prior edition is used. If no value is available for the prior year, the state’s score for the measure is set to zero. For model category and measure weights, see Measures, Weights and Direction. It’s important to note that the rankings are a relative measure of health. Not all changes in rank translate into actual declines or improvements in health.
Ranking measures are selected if they:
- Represent a broad range of health topics that affect the health of the population.
- Are available at the state level.
- Use common measurement criteria across the 50 states.
- Are current and updated periodically.
- Are amenable to change.
Data presented in America’s Health Rankings® reports are aggregated at the state level and cannot be used to make inferences at the individual level. The edition year reflects the year the report was released. The data in each report are compiled from many different data sources and are referenced by the year the data were collected. For some measures, multiple years of data are combined to have sufficient sample size. Values and rankings from prior years are updated on our website to reflect known errors or updates from the reporting source. Error bars on graphs represent the 95% confidence interval.