ONLINE FIRST ORIGINAL INVESTIGATION The Cumulative Effect of Unemployment on Risks

Background: Employment instability is a major source of strain affecting an increasing number of adults in the United States. Little is known about the cumulative ef-fect ofmultiple job losses and unemployment on the risks for acute myocardial infarction (AMI). Methods:We investigated the associations between dif-ferent dimensions of unemployment and the risks for AMI in US adults in a prospective cohort study of adults (N=13 451) aged 51 to 75 years in the Health and Re-tirement Study with biennial follow-up interviews from 1992 to 2010. Unadjusted rates of age-specific AMI were used to demonstrate observed differences by employ-ment status, cumulative number of job losses, and cu-mulative time unemployed. Cox proportional hazards models were used to examine the multivariate effects of cumulative work histories on AMI while adjusting for sociodemographic background and confounding risk factors. Results:Themedian age of the study cohortwas 62 years, and 1061AMI events (7.9%) occurred during the 165 169 person-years of observation. Among the sample, 14.0% of subjects were unemployed at baseline, 69.7 % had 1 or more cumulative job losses, and 35.1 % had spent time unemployed. Unadjusted plots showed that age-specific rates of AMI differed significantly for each dimension of work history. Multivariate models showed that AMI risks were significantly higher among the unemployed (hazard ratio, 1.35 [95 % CI, 1.10-1.66]) and that risks increased incrementally from 1 job loss (1.22 [1.04-1.42]) to 4 or more cumu-lative job losses (1.63 [1.29-2.07]) compared with no job loss. Risks for AMI were particularly elevated within the first year of unemployment (hazard ratio, 1.27 [95 % CI, 1.01-1.60]) but not thereafter. Results were robust after adjustments for multiple clinical, so-cioeconomic, and behavioral risk factors. Conclusions:Unemployment status, multiple job losses, and short periods without work are all significant risk factors for acute cardiovascular events