The methodology underlying America's Health Rankings™ reflects the evolving expectations and role of health in our society and our ability to measure various aspects of health.  The methodology has evolved over the report's 18-year history to capture these changes; however, we have strived to maintain comparability among editions and to provide a useful resource for tracking and evaluating progress. 

The tables that present each component contain three columns: rank, data and score.  They are calculated as follows:

The data is the raw data as obtained from the stated sources and adjusted for age, race and/or population as appropriate.  All age-adjusted data utilizes the population profile for the middle year of data.  For example, if the data is from 2000 to 2002, the standard population is set at 2001.

The score for each state is based on the following formula.  The score is stated as a percentage.

This calculation results in a score of 0.0 for a state with the same value as the national average.  States that have a higher value than the national average will have a positive score while those with lower values will have a negative score.

To prevent an extreme value from excessively influencing a final score, the maximum score any state could receive for a component is limited to the national norm plus or minus two standard deviations.

For several measures, such as Infant Mortality and Infectious Disease, the data from multiple years are combined to provide sufficient sample size to be meaningful. 

Where a value for the United States overall is not available, the national average is set at the average value of the states measured.

The overall score was calculated by adding the scores of each component multiplied by its weight or the percent of total overall ranking.  (Note:  Scores reported for individual components may not add up to the overall scores due to the rounding of numbers.)

The ranking is the ordering of each state according to score.  Ties in scores are assigned equal rankings.

Components adjusted for race include black and white races only.  Other races have been excluded due to data limitations.  Where mortality data for blacks is unreliable due to low counts, the national average for blacks is used.  These states are marked by an asterisk in the Component Tables.

All earlier results have been revised to correct any errors discovered since the release of prior editions.