Background: Previous studies have found evidence of higher mortality rates among unemployed people than among those in employment, but the effect of changes in national unemployment rates on this association is unclear. We studied mortality in both men and women during a period of rapidly increasing unemployment in Finland.
Methods: In this prospective study of mortality in the Finnish population aged 25-59 years (2.5 million people), baseline sociodemographic data were obtained from the 1990 census and information on employment status in 1987-92 from Statistics Finland's labour force data files. Mortality follow-up was established by record linkage to death certificates from 1991 to 1993.
Findings: Individuals who experienced unemployment between 1987 and 1992 had greater mortality than those in employment after control for age, education, occupational class, and marital status. The mortality ratios for men and women unemployed for the first time in 1990, at a time of low national unemployment were 2.11 (95% CI 1.76-2.53) and 1.61 (1.09-2.36), respectively. These values were lower for those who were unemployed for the first time in 1992 when the national unemployment rate was very high (men 1.35 [1.16-1.56], women 1.30 [0.97-1.75]). The jobless who were re-employed had higher mortality than those who were continuously employed, but not as high as those who remained unemployed.
Interpretation: We have found that the association between unemployment and mortality weakens as the general unemployment rate increases. Studies that took place when the unemployment rate was low may thus overestimate the effect of unemployment on mortality because of unaccounted confounding.