Night work, working hours and common mental disorders (PATOHS)

BACKGROUND: Common mental disorders (CMD) are the leading causes of long-term sickness absence.

Night work and shift work has been associated to CMD, but most previous studies are limited by design problems, small study populations, self-reported data and short observation periods. The interaction between working hours and psychosocial work environment is also poorly explored. OBJECTIVES: The study has both etiological and applied research questions.

We will explore the relation between shift work (especially night work), long working hours and CMDs, as well as the interaction with psychosocial work environment.

The goal is to show that routinely collected data can be used to a) identify risk factors for CMD, b) identify workplaces with high risk of sickness absence and c) give the employer recommendations on how to design healthy schedules.METHOD: A cohort has recently been established by 60,000 individuals employed by Stockholm Region between 2008 and 2016.

An update is planned to include the years 2017-2021.

Detailed information on working hours is retrieved from registry-based payroll data for each working day during the study. Outcome variables regarding CMD and sickness absence are obtained from regional and national registers.

We will use longitudinal multivariate analysis to investigate working hours in relation to CMD and sickness absence, also including interaction between working hours and psychosocial work environment. In a non-randomized pseudo trial design, we will study the effect of changing work schedules on CMD.

Finally, we will identify models that can predict workplace risk of long-term sickness absence among employees.EXPECTED RESULTS: This project has the potential to identify risks for mental illness in relation to working hours, based on objective exposures and outcomes with unique detail.

In addition to international publications, the results will be presented as recommendations with applicability for employers in the health care sector.