Effects of a randomized controlled intervention trial on return to work and health care utilization after long-term sickness absence

Background: The aim of the RCT study was to investigate if the effect of a multidisciplinary intervention on return to work ( RTW) and health care utilization differed by participants' self-reported health status at baseline, defined by a) level of somatic symptoms, b) health anxiety and c) self-reported general health. Methods: A total of 443 individuals were randomized to the intervention ( n = 301) or the control group ( n = 142) and responded to a questionnaire measuring health status at baseline. Participants were followed in registries measuring RTW and health care utilization. Relative risk ( RR) and odds ratio ( OR) were used as measures of associations. Results were adjusted for gender, age, educational level, work ability and previous sick leave. Results: Among all responders we found no effect of the intervention on RTW. Among participants with low health anxiety, the one-year probability of RTW was lower in the intervention than in the control group ( RR = 0.79 95 % CI 0.68-0.93), but for those with high health anxiety there was no difference between the groups ( RR = 1.15 95 % CI 0. 84-1.57). Neither general health nor somatic symptoms modified the effect of the intervention on RTW. The intervention had no effect on health care utilization. Conclusions: The multidisciplinary intervention did not facilitate RTW or decrease health care utilization compared to ordinary case management in subgroups with multiple somatic symptoms, health anxiety or low self-rated health. However, the intervention resulted in a reduced chance of RTW among participants with low health anxiety levels.