Return to work among employees with common mental disorders:Study design and baseline findings from a mixed-method follow-up study

Aims: Most research on return-to-work (RTW) has focused on musculoskeletal disorders. To study RTW in employees sick-listed with common mental disorders (CMD), e.g., stress, depression, and anxiety, the National Research Centre for the Working Environment initiated a study on ''Common Mental Disorders, Return-to-work, and Long-term Sickness Absence'' (CORSA). The aim of the study is (1) to identify predictors of RTW from the environmental, the individual, and the health-related domain and (2) to explore the RTW process based on study participants' experiences. The purpose of this paper is to present the study design and the characteristics of the participants, including analyses on non-response and the prevalence of major depression. Methods: CORSA is a mixed-method follow-up study encompassing quantitative and qualitative analyses in a cohort of employees sick-listed with CMD. Participants were all employees who suffered from CMD and whose applications for sickness absence benefits were processed by the Job Centre Copenhagen (a subunit of the municipality) between July and December 2007 (n = 721). Data on predictors for RTW were collected from (1) administrative application forms filled out by all participants when applying for benefits (n = 721), and (2) baseline questionnaires sent to all participants (responders: n = 298). Data on RTW was retrieved from a national sickness absence registry and from 6-month follow-up questionnaires (n = 226). To explore the RTW process we will primarily use data from in-depth interviews with selected participants (n = 16) supplemented with data from the two questionnaires. Conclusions: The mixed method design allows for a more comprehensive understanding of RTW by triangulating qualitative and quantitative methods.