Type of employment relationship and mortality: prospective study among Finnish employees in 1984-2000.

BACKGROUND The study investigated the relationship between the type of employment (permanent/temporary) contract and mortality. Factors through which temporary employment was expected to be associated with increased mortality were the degree of satisfaction with the uncertainty related to temporary work situation (Study 1) and the voluntary/involuntary basis for temporary work (Study 2). METHODS In Study 1 the data consisted of representative survey on Finnish employees in 1984 (n = 4502), which was merged with register-based follow-up data in Statistics Finland covering years 1985-2000. In Study 2 the data consisted of representative survey on Finnish employees in 1990 (n = 3502) with register-based follow-up data covering years 1991-2000. The relative risk of death was examined by conducting Cox proportional hazards analyses for the permanent and the two temporary employment groups, respectively. RESULTS In Study 1 temporary employees feeling the insecure situation unsatisfactory had a 1.95-fold higher risk of mortality than permanent employees (95% CI 1.13-3.35) after adjusted for background, health- and work-related factors. In Study 2 employees in the position of having a temporary job on the involuntarily basis had a 2.59-fold higher risk of mortality than permanent employees (95% CI 1.16-5.80). CONCLUSIONS The present study confirmed that temporary employees are not a homogeneous group, which holds true even for mortality. Those temporary employees, who either felt the insecure situation unsatisfactory or who worked in temporary work involuntarily, had higher risk of mortality than permanent employees.