摘要：Objectives. To elucidate why the inverse association between education level and mortality risk (the gradient) has increased markedly among White women since the mid-1980s, we identified causes of death for which the gradient increased. Methods. We used data from the 1986 to 2006 National Health Interview Survey Linked Mortality File on non-Hispanic White women aged 45 to 84 years (n = 230 692). We examined trends in the gradient by cause of death across 4 time periods and 4 education levels using age-standardized death rates. Results. During 1986 to 2002, the growing gradient for all-cause mortality reflected increasing mortality among low-educated women and declining mortality among college-educated women; during 2003 to 2006 it mainly reflected declining mortality among college-educated women. The gradient increased for heart disease, lung cancer, chronic lower respiratory disease, cerebrovascular disease, diabetes, and Alzheimer’s disease. Lung cancer and chronic lower respiratory disease explained 47% of the overall increase. Conclusions. Mortality disparities among White women widened across 1986 to 2006 partially because of causes of death for which smoking is a major risk factor. A comprehensive policy framework should address the social conditions that influence smoking among disadvantaged women. The inverse association between education level and mortality risk (the gradient) in the United States is well established. 1–3 Higher education levels provide resources that tend to lower mortality risk, including higher incomes, stable jobs, salubrious social ties, healthy lifestyles, self-efficacy, and safe neighborhoods. 4 The gradient has been a long-standing concern among researchers, policymakers, and those who promote public health initiatives. 5,6 Despite the attempts of initiatives such as Healthy People to eliminate health disparities, 6 the gradient increased over the past half century. 7–12 The timing and magnitude of the increase has varied across demographic groups. Although the gradient grew during the 1960s and 1970s more among White men than among White women, 8,10,12 since the mid-1980s it appears to have grown more among women than among men. 13,14 Among White women in particular, this recent growth reflected declines in mortality among the higher educated alongside increases in mortality among the low educated (mortality continued to decline among low-educated men). 13,14 The reasons for the growth in the gradient among women remain unclear. Understanding the reasons is critical for designing strategies to reverse the growth and for projecting future trends in women’s longevity and health care needs. We focused on non-Hispanic White (hereafter White) women because recent increases in mortality among the low-educated in this racial/ethnic group were statistically significant and substantively large. 13–15 For example, during the 1990s life expectancy at age 25 years among non-Hispanic adults with 12 or fewer years of education decreased by 0.9 years among White women ( P < .001) compared with 0.2 years among Black women ( P < .1). 13 In addition, the best insights may be gleaned by examining racial/ethnic groups separately, given historical differences in school quality, employment, immigration patterns, family structure, and cause of death distributions. The first step toward explaining the growth is identifying causes of death for which the gradient increased. A few studies have examined such trends among White women. Although informative, they largely focused on 2 time points, dichotomized education levels, a select group of causes, and a small age range. 13,15,16 They found that roughly one quarter of the gradient’s growth during the 1990s among White women aged 45 to 84 years was because of deaths from lung cancer and chronic obstructive pulmonary disease. 13 In a younger group of White women, aged 25 to 64 years, deaths from accidents contributed the largest percentage to the growth during the mid to late 1990s. 15 However, many questions remain unanswered. For example, has the growth been constant or has it accelerated, decelerated, or plateaued? Which education groups were responsible for the growth, over which time periods, and for which causes of death? What do the trends suggest about future disparities? We have provided insights into these largely overlooked but important questions. We performed a comprehensive analysis of trends in mortality by cause of death and education level from 1986 to 2006 among White women. We examined 4 time periods spanning 21 years to display nonlinearities in the trends. We also analyzed 4 education levels, including a bachelor’s degree, a critical improvement given the rising importance of a college degree for access to health-enhancing resources. We included women aged 45 to 84 years, which captures the majority of deaths among White women during the study period. We assessed trends in 12 causes of death for which we could reliably estimate death rates. Last, we calculated relative and absolute measures of the gradient because they may move in different directions. 17
