A multisite randomized controlled trial on time to self-support among sickness absence beneficiaries. The Danish national return-to-work programme

Maj Britt D. Nielsen, Jørgen Vinsløv Hansen, Birgit Aust, Torill Tverborgvik, Birthe L. Thomsen, Jakob Bue Bjorner, Ole Steen Mortensen, Reiner Rugulies, Glen Winzor, Palle Ørbæk, Trine Helverskov, Nicolai Kristensen, Otto Melchior Poulsen