Using sickness absence records to predict future depression in a working population: Prospective findings from the GAZEL cohort

Objectives. We tested the hypothesis that sickness absence from work predicts workers' risk of later depression. Methods. Study participants (n=7391) belonged to the French GAZEL cohort of employees of the national gas and electricity company. Sickness absence data (1996-1999)wereobtainedfromcompany records.Participants'depressionin 1996 and 1999 was assessed with the Center for Epidemiologic Studies-Depression (CES-D) scale. The analyses were controlled for baseline age, gender, marital status, occupational grade, tobacco smoking status, alcohol consumption, sub-threshold depressive symptoms, and work stress. Results. Among workers who were free of depression in 1996, 13% had depression in 1999. Compared with workers with no sickness absence during the study period, those with sickness absence were more likely to be depressed at follow-up (for 1 period of sickness absence, fully adjusted odds ratio [OR]=1.53, 95% confidence interval [CI]=1.28, 1.82; for 2 or more periods, fully adjusted OR=1.95, 95% CI=1.61, 2.36). Future depression was predicted both by psychiatric and nonpsychiatric sickness absence (fully adjusted OR=3.79 [95% CI=2.81, 5.10] and 1.41 [95% CI=1.21, 1.65], respectively). Conclusions. Sickness absence records may help identify workers vulnerable to future depression.