Predictors of suicidal behaviour in 36,304 individuals sickness absent due to stress-related mental disorders - a Swedish register linkage cohort study

BACKGROUND Stress-related mental disorders (SRMD), which correspond to the diagnostic code F43 in the International Classification of Diseases, version 10, rank among the leading causes of sickness absence in several European countries. Despite the size of this health problem, research on risk factors for severe medical outcomes, like suicidal behavior, is lacking to date. The aim of this study was to investigate predictors of suicide attempt and suicide among sickness absentees with SRMD. METHODS A cohort of 36,304 non-retired individuals, aged 16-64 years on 31.12.2004, with at least one sickness absence spell due to SRMD, initiated in 2005, was followed up with regard to suicide attempt (2006-2009) and suicide (2006-2008). Univariate and multivariate hazard ratios (HR) with 95% confidence intervals (CI) were estimated for a number of predictors. RESULTS During the follow-up period, 266 individuals attempted suicide and 34 committed suicide. In the multivariate analyses, the following factors increased the risk of suicide attempt: =< 25 years of age, low educational level, lone parenthood, > 1 sickness absence spell, long duration of the first spell of sickness absence due to SRMD (> 180 days), > 4 and > 8 days of inpatient care due to somatic or mental diagnoses (2000-2005), and > 4 and > 1 outpatient visits due to somatic or mental diagnoses (2001-2005), respectively. Hazard ratios ranged from 1.4 to 4.2. Health care due to mental diagnoses and > 1 spell of sickness absence regardless of diagnosis were predictive of suicide. CONCLUSIONS Several predictors related to socio-demographics, sickness absence and health-care consumption were identified as risk factors for suicidal behavior. Consideration of these risk factors is of both clinical and public health importance.