Outcomes
SECONDARY
Data were obtained at baseline through multiple sources: researcher-administered semi-structured interviews, self-reported questionnaires and register-based data. At 24-month follow-up, data were obtained through self-reported questionnaires and register-based weekly data from baseline to follow-up. To capture the complex nature of the RTW process, several outcomes were used to describe intervention effects at 24-month follow-up: time to RTW (secondary outcome) and the pre-registered explorative outcomes of weeks in work and proportion in work. The number of recurrent sick leaves was a post-hoc exploratory outcome. Self-reported data were used to measure symptoms, level of functioning, quality of life, self-efficacy and presenteeism (being ill whilst working). All self-assessed outcomes at 24-month follow-up were pre-registered exploratory outcomes. These are described in Supplement 3.