Job strain linked to increased sick leaves: study

Workers with high job demands and job strain are at increased risk of sick leave due to mental disorders, a new Swedish study has found.
Researchers used data from a Swedish national twin study to examine how rates of sick leave for mental health reasons are affected by psychosocial factors at work.
On five-year follow-up of nearly 12,000 workers, the rate of sick leave due to mental disorders was about eight per cent. Three-fourths of workers with mental health sick leave were women.
Workers with high job demands were at greater risk of sick leave due to mental disorders. Risk was also increased for workers with job strain, defined as high job demands with low control, and "iso-strain," defined as high demands and low control plus low levels of social support at work.

Workers with multiple unhealthy behaviours also had higher rates of mental health sick leave. Smoking was a significant risk factor, but alcohol use was not. High physical activity level was a protective factor.
The increased risks associated with high job demand and job strain were unaffected by familial factors or health behaviours. Familial factors did seem to contribute to the risks associated with low job support, smoking, and unhealthy behaviours.

Mental disorders are a common and costly cause of work disability. In Sweden, mental disorders are the most common reason for sick leave.
The study adds to previous evidence that psychosocial conditions at work affect rates of mental health sick leave - and may suggest ways of reducing this risk.

"Interventions to reduce sick leave due to mental disorders that focus on improving the psychosocial work environment, especially reducing high psychosocial job demands, may prove effective," Lisa Mather of Karolinska Institutet, Stockholm and co authors wrote.
They added that that efforts aimed at improving health behaviours only - without also addressing the work environment - may be less likely to reduce mental health sick leave.
The study was published in the Journal of Occupational and Environmental Medicine.