摘要：Objectives. Individuals may cope with perceived stress through unhealthy but often pleasurable behaviors. We examined whether smoking, alcohol use, and physical inactivity moderate the relationship between perceived stress and the risk of death in the US population as a whole and across socioeconomic strata. Methods. Data were derived from the 1990 National Health Interview Survey’s Health Promotion and Disease Prevention Supplement, which involved a representative sample of the adult US population (n=40335) and was linked to prospective National Death Index mortality data through 1997. Gompertz hazard models were used to estimate the risk of death. Results. High baseline levels of former smoking and physical inactivity increased the impact of stress on mortality in the general population as well as among those of low socioeconomic status (SES), but not middle or high SES. Conclusions. The combination of high stress levels and high levels of former smoking or physical inactivity is especially harmful among low-SES individuals. Stress, unhealthy behaviors, and low SES independently increase risk of death, and they combine to create a truly disadvantaged segment of the population. Perceived stress is a negative affective state that individuals may attempt to relieve or cope with through unhealthy but often pleasurable behaviors. 1 – 9 High levels of perceived stress are associated with smoking initiation, increased smoking levels, less successful smoking cessation attempts, drinking alcohol more often and in heavier quantities, increased problem drinking, and reports of positive attitudes toward drinking. 4 , 10 – 23 Some people exercise to control their stress, 24 but most individuals respond to stress by exercising less frequently and at lower levels because sedentary behavior is more rewarding in the short term. 4 , 10 , 23 , 25 Stress and unhealthy behaviors each increase the risk of death. 15 , 26 – 36 Numerous social stressors and high levels of perceived stress have been shown to be positively associated with mortality. 15 , 26 Current and former smoking and physical inactivity are also positively associated with mortality. 27 – 32 Alcohol consumption has a J-shaped relationship with mortality; abstainers and heavy drinkers are at increased risk of death relative to moderate drinkers. 29 , 33 – 36 To our knowledge, no research has examined whether unhealthy behaviors moderate the relationship between stress and mortality. Our first aim in this study was to examine whether unhealthy behaviors moderate the stress–mortality relationship in a nationally representative sample of US adults. There are 3 possible relationships between stress, health behaviors, and the risk of death. First, the “double jeopardy” perspective suggests that multiple risk factors combine to increase the risk of death more than a single risk factor alone would indicate. 37 , 38 Smoking, alcohol use, and physical inactivity may be pleasurable but deleterious strategies for coping with perceived stress, and they may inadvertently increase the effects of stress on mortality. 39 , 40 Second, unhealthy behaviors may allow individuals to cope effectively with stress. 3 , 5 , 7 , 8 , 41 Unhealthy behaviors and high stress levels are each associated with increased mortality, but unhealthy behaviors may nevertheless reduce the effects of stress on mortality. Finally, the null hypothesis implies that unhealthy behaviors will not moderate the stress–mortality relationship. Our second aim was to examine whether unhealthy behaviors moderate the impact of stress on mortality differently across different socioeconomic strata. The social vulnerability hypothesis suggests that the combination of unhealthy behaviors and high stress levels may be particularly risky among individuals of low socioeconomic status (SES), who might be more vulnerable, or less resilient, to accumulating health risks. 42 , 43 Those who are less advantaged “experience multiple threats to their health, with each threat making the other more serious.” 43 (p302) By contrast, the “Blaxter hypothesis” posits that unhealthy behaviors may be less harmful among those in low-SES groups, precisely because members of these groups already face numerous insults resulting from unsafe housing, work, and neighborhood environments. 44 Improving unhealthy behaviors without ameliorating underlying socioeconomic disadvantages may yield few health benefits. 3 , 45 – 47 Thus, if unhealthy behaviors increase the relationship between stress and mortality, their influence may be attenuated among low-SES individuals.
