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标题：Socioeconomic Status and the Black–White Mortality Crossover
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作者：Jessica M. Sautter ; Patricia A. Thomas ; Matthew E. Dupre 等
期刊名称：American journal of public health
印刷版ISSN：0090-0036
出版年度：2012
卷号：102
期号：8
页码：1566-1571
DOI：10.2105/AJPH.2011.300518
语种：English
出版社：American Public Health Association
摘要：Objectives. We investigated associations among age, race, socioeconomic status (SES), and mortality in older persons and whether low SES contributes to the Black–White mortality crossover (when elevated age–specific mortality rates invert). Methods. We used panel data from the North Carolina Established Populations for Epidemiologic Studies of the Elderly to test the main and interactive effects of SES on mortality. Results. Discrete-time hazard models showed that the association between low education and mortality did not vary by race or age and was only significant for men. For women, the effect of low income diminished with age and had little impact on the crossover. For men, low income varied by race and age, altering the Black–White crossover and producing low–high income crossovers at advanced ages. Conclusions. Low education and income were associated with increased mortality risk for older adults, but only low income had a differential impact on the Black–White mortality crossover. A primary route to reducing mortality differentials in later life is to prevent the disproportionate selective mortality of Blacks and the poor earlier in the life course. In the United States, it is well established that Blacks exhibit higher rates of mortality than do Whites throughout most of the life course. 1,2 By late life, however, there is evidence that a mortality “crossover” occurs when elevated age-specific mortality rates among Blacks invert with those of Whites at advanced ages. 3–6 Explanations for this phenomenon are not well established and are widely debated. Current research suggests 2 prevailing explanations: age misreporting on death certificates and population heterogeneity in frailty. Age misreporting (i.e., overstatement of age) on death certificates occurs and is more common among Blacks; this error can bias mortality estimates downward at the oldest ages. 7,8 However, some analyses show that all-cause and cause-specific crossovers are postponed to later ages rather than eliminated when data are adjusted for age misreporting. 9,10 The second and more prevalent viewpoint is that mortality inversion at advanced ages is attributable to differential heterogeneity in the susceptibility of dying, also termed frailty or selective mortality. 11,12 According to this perspective, disadvantaged subgroups in a population (e.g., Blacks) will experience systematically higher mortality at younger ages, which in turn leaves a more robust group of disadvantaged individuals in the surviving population (selection). As age increases, the composition of the total population is weighted toward the robust members of the disadvantaged subgroup who now exhibit lower mortality than the advantaged subgroup, who experience an acceleration of mortality at older ages. 12 Only a handful of studies have incorporated substantive covariates to help identify sources of heterogeneity in frailty. 3,4,13 We hypothesized that the unequal distribution of socioeconomic status (SES) contributes to heterogeneity in frailty and the mortality crossover paradox. The association between SES and mortality has been documented in studies. 14,15 Research also consistently demonstrates that levels of SES are significantly lower among Blacks than among Whites and among women than among men. 16,17 Studies also suggest that the health benefits of SES are not uniform by race, gender, or age. 18–20 Our study was the first to our knowledge to examine whether low education and income capture important sources of heterogeneity in individual frailty that contribute to the Black–White mortality crossover. It was also the first to investigate how multiple systems of stratification—age, race, gender, and SES—operate simultaneously to shape mortality differentials among older adults. We discuss the implications of this research in the context of social inequalities in the United States and highlight the utility of using the mortality crossover as a tool to document the dynamic effects of these forms of stratification across age.