Socio-demographic, employment, and clinical factors
SSIA
Employee characteristics and employment information were collected by a web-based questionnaire at baseline. Sociodemographic characteristics were age, gender, country of origin, cohabitation status, children living at home (under the age of 16 years), household responsibilities, and level of education (primary/secondary, higher education/university). Employment information was contract type, sector (municipality/county/state, private, other), type of work (mentally demanding, physically demanding, both), ordinary working hours (full-time, part-time), and work tenure in years (≤ 2, 3–5, ≥ 6). Sick leave information was full-time (100%) or part-time (25/50/75%) sick leave of ordinary working hours. Baseline diagnosis was collected from the Swedish Social Insurance Agency’s (SSIA) register Micro Data for the Analysis of Social Insurance register (MiDAS).Covariates were collected from the baseline variables and included the variables age, level of education, sick leave from ordinary working hours, and randomisation (intervention, control).