摘要：Objectives. We estimated the number of deaths attributable to social factors in the United States. Methods. We conducted a MEDLINE search for all English-language articles published between 1980 and 2007 with estimates of the relation between social factors and adult all-cause mortality. We calculated summary relative risk estimates of mortality, and we obtained and used prevalence estimates for each social factor to calculate the population-attributable fraction for each factor. We then calculated the number of deaths attributable to each social factor in the United States in 2000. Results. Approximately 245 000 deaths in the United States in 2000 were attributable to low education, 176 000 to racial segregation, 162 000 to low social support, 133 000 to individual-level poverty, 119 000 to income inequality, and 39 000 to area-level poverty. Conclusions. The estimated number of deaths attributable to social factors in the United States is comparable to the number attributed to pathophysiological and behavioral causes. These findings argue for a broader public health conceptualization of the causes of mortality and an expansive policy approach that considers how social factors can be addressed to improve the health of populations. In 1993, an article provocatively titled “Actual Causes of Death in the United States” offered a new conceptualization of cause-of-death classification, one that acknowledged and quantified the contributions of behavior rather than the more typical pathological explanations recorded on death certificates. 1 The authors, McGinnis and Foege, found that the most prominent contributor to mortality in 1990 was tobacco (400 000 deaths), followed by diet and activity patterns (300 000 deaths). A decade later, updated findings by Mokdad et al. 2 using data from 2000 showed progress in some areas but the growing contribution of obesogenic behavior (poor diet and physical inactivity). Despite controversy over the methods used to derive the attributable numbers of deaths and the validity of their estimates, especially in the article by Mokdad et al., the findings of both articles have been influential, are frequently cited and debated in the peer-reviewed literature, 3 – 12 and have been cited in discussions of national public health priorities. 13 In a 2004 editorial accompanying the article by Mokdad et al., McGinnis and Foege noted that although it is also important to better capture and apply evidence about the centrality of social circumstances to health status and outcomes … the data are still not crisp enough to quantify the contributions [of social circumstances] in the same fashion as many other factors. 14 (p1264) In the past 15 years, there has been growing interest in the social determinants of health, and several proposed frameworks describe the effects on individual and population health of social factors at multiple levels, including behavioral factors, features of an individual's social network and neighborhood, and social and economic policies. 15 , 16 Numerous studies have demonstrated a link between mortality and social factors such as poverty and low education. Although the proposed causal chain linking adverse social factors to poor health is complicated, the evidence points to mechanisms including risky health behaviors (e.g., smoking), inadequate access to health care, and poor nutrition, housing conditions, or work environments. 17 – 20 Social relationships have also been linked to mortality, as social ties influence health behaviors and social support buffers against stress, which in turn affects immune function, cardiovascular activity, and the progression of existing disease. 21 , 22 Negative social interactions, including discrimination, have been linked to elevated mortality rates, potentially through adverse effects on mental and physical health as well as decreased access to resources. 23 , 24 Finally, characteristics of one's residential environment may influence mortality through investment in health and social services in the community, effects of the built environment, and exposure to violence, stress, and social norms that promote adverse health behaviors. 25 – 28 To date, few studies have provided population estimates of deaths attributable to social factors. For example, 1 study estimated that over 1 million deaths from 1996 to 2002 would have been avoided if all adults in the US population had at least a college education. 29 Other studies have estimated attributable fractions for mortality of 2% to 6% for poverty (depending on the year and data source), 30 , 31 9% to 25% for income inequality (depending on age group), 32 and 18% to 25% for low neighborhood socioeconomic status (depending on gender and racial/ethnic group). 33 Building on these previous efforts, we aimed to estimate the number of deaths in the United States attributable to social factors, using a systematic review of the available literature combined with vital statistics data.
