Involuntary job loss as a risk factor for subsequent myocardial infarction and stroke: findings from the Health and Retirement Survey.

Involuntary job loss in the years immediately preceding retirement can be a stressful event that has been shown to be associated with adverse health and behavioral consequences [Gallo et al., 2000, 2001]. Older workers are at increased risk for negative outcomes for a number of reasons. First, workers nearing retirement age are often ill prepared to finance post-employment consumption [Bernheim, 1997]. Second, high pre-displacement wages and non-portable experience may limit reemployment opportunities, resulting in extended unemployment spells [Fallick, 1996; Farber, 1996; Polsky, 1999; Chan and Stevens, 2001]. Research also indicates that the wages of older workers are significantly reduced upon reemployment [Couch, 1998]. Finally, older individuals also have a greater burden of preexisting financial, social, and medical factors than do younger individuals. Given substantial epidemiologic evidence indicating the significant role of stress in cardiovascular diseases [Dorian and Taylor, 1984; Rozanski et al., 1999; Kubzansky and Kawachi, 2000], it is plausible that workers who experience involuntary job loss may be at increased risk of such diseases, including myocardial infarction (MI) and stroke. For many older individuals, involuntary job loss is not only associated with a substantial loss of income, but also the severance of work-based social interactions [Iversen and Klausen, 1986] and the stigma of unemployment, which may produce stress. Such stress may, in turn, lead to negative emotions, such as anxiety and depression. Recent reviews of published research [Rozanski et al., 1999; Kubzansky and Kawachi, 2000] conclude that chronic states of anxiety and prolonged depression are consistently associated with elevated risk of coronary heart disease (CHD) events, including both fatal and non-fatal MI. A number of studies have investigated the relationship between national unemployment rates and the prevalence of various health outcomes related to cardiovascular risk. This research, which was conducted on populations rather than on individuals, has revealed significant associations between unemployment and cardiovascular mortality [Jin et al., 1995; Weber and Lehnert, 1997] and cerebrovascular mortality [Brenner, 1983; Ahmed et al., 1989; Franks et al., 1991]. However, such ecologic studies present aggregate data, and thus cannot confirm that job loss increases cardiovascular disease in individuals. At the individual level, both cross-sectional and longitudinal studies of the association between unemployment and cardiovascular and cerebrovascular disease have been undertaken. The cross-sectional research [Cook et al., 1982; Iversen et al., 1987; Martikainen, 1990; Brackbill et al., 1995] has found modestly increased prevalence of CHD [Cook et al., 1982], cardiovascular symptoms [Iversen et al., 1987], prevalence of hypertension [Brackbill et al., 1995], and cardiovascular and cerebrovascular mortality [Martikainen, 1990] among unemployed versus employed workers. The longitudinal research is limited to four relevant studies [Kasl and Cobb, 1980; Iversen et al., 1989; Janlert, 1992; Schnall et al., 1992], and has reported mixed results. In a Danish study of 880 laid-off shipyard workers and 441 controls from another shipyard where no layoffs occurred, Iversen et al. [1989] found among the laid-off workers higher rates of hospital admissions for cardiovascular diseases in a 3-year follow-up period. In a study of 297 laid-off Swedish building laborers, Janlert [1992] reported that those who remained unemployed within the 2-year follow-up had significantly increased blood pressure over the follow-up period relative to reemployed workers. In contrast, the remaining longitudinal studies [Kasl and Cobb, 1980; Schnall et al., 1992], both conducted in the United States, found less evidence of an association between job loss and subsequent cardiovascular risk. Studying workers displaced in a plant closing, Kasl and Cobb [1980] reported that, while blood pressure was modestly increased during the anticipation phase prior to plant closing, this increase did not persist after termination. Schnall et al. [1992], in a study of 139 laid-off employees from a brokerage firm, found limited support for increased blood pressure levels in the anticipation phase, as reported by Kasl and Cobb [1980], but discovered no evidence of a persistent elevation in these levels. The authors of a recent, comprehensive review of the literature [Weber and Lehnert, 1997] have concluded that job loss should not be viewed as a risk factor for poor cardiovascular outcomes. There are several reasons why the existing research leaves our understanding of the relationship between involuntary job loss and cardiovascular/cerebrovascular disease limited. First, much of the evidence is ecologic, and thus does not represent the experience of individuals. Second, while several studies indicate a cross-sectional association between unemployment and cardiovascular disease, the causal direction of these associations cannot be inferred. Third, longitudinal studies, whose methodology is better suited to assess any causal relationship, are few, and offer somewhat contrary findings. Fourth, each of the relevant longitudinal studies of involuntary job loss and cardiovascular risk examined a relatively small, selected group of younger individuals, and with one exception [Iversen et al., 1989], assessed changes in blood pressure and serum cholesterol rather than MI or stroke. Moreover, just two of the longitudinal studies [Kasl and Cobb, 1980; Schnall et al., 1992] were conducted in the United States, and none studied older workers. And finally, we could find no study that examined the influence of involuntary job loss on the onset of specific cardiovascular or cerebrovascular outcomes, such as subsequent MI or stroke, as we do in this research. The objective of this study is to estimate the risk of onset of MI and of stroke associated with involuntary job loss among workers nearing retirement relative to individuals who continue to work. This is a companion study to our earlier studies investigating the impact of job loss on subsequent physical functioning and mental health [Gallo et al., 2000], and subsequent alcohol consumption [Gallo et al., 2001].