THE IMPACT OF UNEMPLOYMENT ON HEALTH - A REVIEW OF THE EVIDENCE

Objective: To review the scientific evidence supporting an association between unemployment and adverse health outcomes and to assess the ev idence on the basis of the epidemiologic criteria for causation. Data sources: MEDLINE was searched for all relevant articles with the use o f the MeSH terms ''unemployment,'' ''employment,'' ''job loss,'' ''eco nomy'' and a range of mortality and morbidity outcomes. A secondary se arch was conducted for references from the primary search articles, re view articles or published commentaries. Data and definitions of unemp loyment were drawn from Statistics Canada publications. Study selectio n: Selection focused on articles published in the 1980s and 1990s. Eng lish-language reports of aggregate-level research (involving an entire population), such as time-series analyses, and studies of individual subjects, such as cross-sectional, case-control or cohort studies, wer e reviewed. In total, the authors reviewed 46 articles that described original studies. Data extraction: Information was sought on the assoc iation (if any) between unemployment and health outcomes such as morta lity rates, specific causes of death, incidence of physical and mental disorders and the use of health care services. Information was extrac ted on the nature of the association (positive or negative), measures of association (relative risk, odds ratio or standardized mortality ra tio), and the direction of causation (whether unemployment caused ill health or vice versa). Data synthesis: Most aggregate-level studies re ported a positive association between national unemployment rates and rates of overall mortality and mortality due to cardiovascular disease and suicide. However, the relation between unemployment rates and mot or-vehicle fatality rates may be inverse. Large, census-based cohort s tudies showed higher rates of overall mortality, death due to cardiova scular disease and suicide among unemployed men and women than among e ither employed people or the general population. Workers laid off beca use of factory closure have reported more symptoms and illnesses than employed people; some of these reports have been validated objectively . Unemployed people may be more likely than employed people to visit p hysicians, take medications or be admitted to general hospitals. A pos sible association between unemployment and rates of admission to psych iatric hospitals is complicated by other institutional and environment al factors. Conclusions: Evaluated on an epidemiologic basis, the evid ence suggests a strong, positive association between unemployment and many adverse health outcomes. Whether unemployment causes these advers e outcomes is less straightforward however, because there are likely m any mediating and confounding factors, which may be social, economic o r clinical. Many authors have suggested mechanisms of causation, but f urther research is needed to test these hypotheses.