Trends in health equity in mortality in the United States, 1969-2019

Abstract

Rationale: Health equity is a significant concern of public health, yet a comprehensive assessment of health equity in the United States over time is lacking. While one might presume that overall health will improve with rising living standards, no such presumption is warranted for health equity, which may decline even as average health improves.

Objectives: To assess trends in national and state-level health equity in mortality for people up to age 25, ages 25-64 and aged 65 and older.

Methods: A health equity metric was calculated as the weighted mean life expectancy relative to a benchmark level, defined as the life expectancy of the most socially-privileged subpopulation (white, non-Latinx males with a college education or higher).We analyzed 114,558,346 death records from the National Center for Health Statistics, from January 1, 1969 to December 31, 2019 to estimate health equity annually at the national and state-level. Using ICD-9/ICD-10 classification codes, inequities in health were decomposed by major causes of death.

Results: From 1969 to 2019, health equity in the United States improved (+0.36 points annually [95% CI 0.31-0.41]), albeit at a slower rate over the last two decades (+0.08 points annually [95% CI 0.03-0.14] from 2000 to 2019, compared to +0.57 points annually from 1969 to 2000 [95% CI 0.50-0.65]). Health equity among those under 25 improved substantially (+0.82 points annually [95% CI 0.75-0.89]) but remained flat for adults 25-64 (-0.01 points annually [95% CI -0.03-0.003]) For those over 65, health equity displayed a downward trend (-0.08 points annually [95% CI -0.09 to -0.07]). Gains in equity from reduced unintentional injuries and homicides have been largely offset by rising mortality attributable to drug overdoses.

Conclusions: The US is failing to advance health equity, especially for adults. Keeping policy-makers accountable to a summary measure of health equity may help coordinate efforts at improving population health.

Fig. 1

National Health Equity Metric (HEM) from 1969 to 2019 Notes: HEM is presented in units such that a value of 100 represents perfect health equity. The vertical black line denotes change in definition of privileged group for health potential benchmark (from white males for 1969– 1989 to white, non-Latinx males with at least a college education for 1990–2019). Years prior to 1990 are shifted downwards to make estimates across two periods more directly comparable (see Appendix A).

Fig. 2

State Health Equity Metrics (HEMs) by Quantile from 1969 to 2019 Notes: Darker hues indicate better HEM scores. For HEMs from 1969 to 1989, the privileged group for health potential benchmark is white males, while for 1990 and onward, this definition is white, non-Latinx males with at least a college education. Years prior to 1990 are shifted downwards to make estimates across two periods more directly comparable (see Appendix A). For each age group, state HEMs are grouped into nine category quantiles for all years shown in the period (51 states * 6 years displayed = 306 possible HEM values, or 9 groups of 34 states across all years).

Fig. 3

Cumulative Health Inequity by Grouped Causes, 1979-2019 Notes: This figure shows health inequity, as opposed to previous figures which show health equity. Health inequity for all causes sums up to the distance between the national Health Equity Metric and 100. Causes in the key are arranged from top to bottom in the figure. Deaths of Despair include mortalities attributed to drug overdose, suicide, and alcohol-related liver Disease. Chronic conditions include mortalities attributed to respiratory disease, stroke, Alzheimer's, kidney disease, flu, septicemia, and hypertension. Black vertical line represents the change in definition of the privileged: from 1969 to 1989, the privileged group for health potential benchmark is white males, while for 1990 and onward, this definition is white, non-Latinx males with at least a college education. Years prior to 1990 are shifted downwards to make estimates across two periods more directly comparable (see Appendix A). Gray vertical line represents the change from ICD-9 to ICD-10 cause of death coding. We adopt the comparability ratio methodology proposed by Anderson to make the two periods more comparable (R. N. Anderson et al., 2001).

Fig. 4

Increase in Health Inequity from Drug Overdose, 1979-2019 Notes: Health inequity for all causes sums up to the distance between the Health Equity Metric and 100. For reference, in 1990 the poorest performing state for the population 25–64 (NM = 0.91) had lower levels of health inequity attributable to drug overdoses than the best performing state in 2019 (NE = 1.08). For the population 0–24, only one state in 1990 (NM = 0.38) had worse levels of health inequity attributable to drug overdose than any state in 2019 (HI = 0.33). For the population 65 and older, only three states in 1990 (AR, DC, & VT) had worse levels of health inequity attributable to drug overdose than any state in 2019 (NH = 0.01). DC is omitted for the population 65 and older in 2019 because it is an outlier (0.55 points).