Widening Socioeconomic Inequalities in US Life Expectancy, 1980-2000

Background: This study examines changes in the extent of inequalities in life expectancy at birth and other ages in the United States between 1980 and 2000 by gender and socioeconomic deprivation levels.

Methods: A factor-based deprivation index consisting of 11 education, occupation, wealth, income distribution, unemployment, poverty, and housing quality indicators was used to define deprivation deciles, which were then linked to the US mortality data at the county-level. Life expectancy estimates were developed by age, gender, and deprivation levels for three 3 year time periods: 1980-82, 1989-91, and 1998-2000. Inequalities in life expectancy were measured by the absolute difference between the least-deprived group and each of the other deprivation deciles. Slope indices of inequality for each gender and time period were calculated by regressing life expectancy estimates on deprivation levels using weighted least squares models.

Results: Those in less-deprived groups experienced a longer life expectancy at each age than their counterparts in more-deprived groups. In 1980-82, the overall life expectancy at birth was 2.8 years longer for the least-deprived group than for the most-deprived group (75.8 vs 73.0 years). By 1998-2000, the absolute difference in life expectancy at birth had increased to 4.5 years (79.2 vs 74.7 years). The inequality indices also showed a substantial widening of the deprivation gradient in life expectancy during the study period for both males and females.

Conclusions: Between 1980 and 2000, those in higher socioeconomic groups experienced larger gains in life expectancy than those in more-deprived groups, contributing to the widening gap.