Prospective Cohort Analysis of the Predictive Validity of a Screening Instrument for Severe Restrictions of Work Ability in Patients with Musculoskeletal Disorders

Objective The aim of this study was to determine whether the Screening-Instrument zur Feststellung des Bedarfs an medizinisch-beruflich orientierter Rehabilitation (SIMBO) screening instrument can identify persons with a high work disability risk. Design Patients with chronic musculoskeletal disorders and participation in a rehabilitation program were included in the analysis. Data were collected by questionnaires at admission and at the 6-mo follow-up. Failed return to work (RTW; i.e., unemployment or active employment with sick leave of >12 wks in the follow-up) was the primary outcome. Additional outcome data were obtained from the physician's discharge form (e.g., assessment of work ability). Receiver operating characteristic analyses and logistic regression models were used to analyze the data. Results Valid data were available for 1755 participants. Of these, 25% reported failed RTW. The area under the curve of the SIMBO score predicting failed RTW was 0.81 (0.79-0.83). The optimal cutoff to identify failed RTW was 23 points (of 100). The odds of failed RTW, unemployment, and sick leave of more than 12 wks were increased 12, 11, and 10 times for the persons with a SIMBO score of 23 points or greater compared with the persons with lower SIMBO scores. The odds of reduced work time capacity were increased 21 times. Conclusions The SIMBO predicts work disability in patients with chronic musculoskeletal disorders. Further research should focus on its predictive validity in patients with other disorders and within other rehabilitation systems.