Methods A prospective cohort study was performed including 810 newly sick-listed patients (MSD 62% and MD 38%). The baseline questionnaire included sociodemographic characteristics and measures of work ability. The 3-month follow-up questionnaire included measures of work ability, type of intervention received, and judgment of usefulness.Results Twenty-five percent received medical intervention modalities (MI) only, 45% received a combination of medical and rehabilitative intervention modalities (CRI) and 31% received workrelated interventions combined with medical or rehabilitative intervention modalities (WI).Behavioural treatments were more common for patients with MD compared with MSD and exercise therapy were more common for patients with MSD. The most prevalent workplace interventions were adjustment of work tasks or the work environment. Among patients with MD, WI was found to be useful and improved work ability significantly more compared with only MI or CRI. For patients with MSD, no significant differences in improved work ability were found between interventions.Conclusions Patients with MD who received a combination of work-related and clinical interventions reported best usefulness and best improvement in work ability. There was no difference in improvements in work ability between rehabilitation methods in the MSD group.There seems to be a gap between scientific evidence and praxis behaviour in the rehabilitation process. Unimodal rehabilitation was widely applied in the early rehabilitation process, a multimodal treatment approach was rare and only one-third received work-related interventions.It remains a challenge to understand who needs what type of intervention.