Outcome
RECRUITMENT
The outcome of interest in this study was time to stable RTW at 6 and 12 months after randomization in the IBBIS project, hereafter referred to as baseline. Stable RTW was defined as not receiving sick leave benefits for a consecutive period of four weeks. Data on sick leave benefits were obtained from the national DREAM database and the Income Statistics Register. The DREAM database is administered by the Danish Agency for Labor Market and Recruitment and includes all persons with a Danish civil personal registration number (CPR) who have received social benefits, or any other type of transfer income, on a weekly basis (Hjollund et al. 