Mental illness rates among employees with fixed-term versus permanent employment contracts: a Danish cohort study

Abstract

Purpose: It has been hypothesized that employment in a fixed-term instead of permanent contract position is associated with an increased risk of development of mental health problems. The present study aimed at estimating rate ratios between fixed-term and permanent employees in the Danish labor force, for use of psychotropic drugs and psychiatric hospital treatment due to mood, anxiety or stress-related disorders, respectively. Methods: Employment data were drawn from the Danish Labor Force Survey of 2001–2013, which is a part of the European Labor Force Survey. Full-time employed survey participants without mental illness at the baseline interview (N = 106,501) were followed in national health registers for up to 5 years. Poisson regressions were used to estimate rate ratios for redeemed prescriptions of psychotropic drugs and psychiatric hospital treatments due to mood, anxiety or stress-related disease. The analyses were controlled for age, gender, industrial sector, nighttime work, level of education, calendar year, disposable family income and social transfer payments within 1 year prior to the baseline interview. Results: The rate ratio for hospital diagnosed mood, anxiety or stress-related disorders among employees with fixed-term vs. permanent employment contracts was estimated at 1.39 (99.5% CI 1.04–1.86), while the corresponding rate ratio for redeemed prescriptions of psychotropic drugs was estimated at 1.12 (99.5% CI 1.01–1.24). Conclusion: The present study supports the hypothesis that employment in a fixed-term rather than permanent contract position is associated with an increased risk of developing mental health problems. International registered report identifier (IRRID): DERR2-10.2196/24392.