Primary Outcome
The primary outcome was total number of days on sick leave during the 6-month time period after the intervention. Net days (all causes) of sick leave was used for register based sick leave data. Register based sick leave data were collected from the Swedish Social Insurance Agency, which manages sickness cash benefit for sick leave spells exceeding 14 days. Baseline data were collected for 6-months before intervention. For self-reported sick leave data, an item from the Work Ability Index was used at baseline and 6-months follow-up, where participants report days on sick leave during the last year: 0 days, 1–7 days, 8–24 days, 25–99 days, 100–356 days [