Objective: To investigate whether an interdisciplinary rehabilitation for chronic musculoskeletal disorders is associated with changes in the purchase of prescribed pain medication.

Design:

Prospective register-based study.

Subjects:  Employees in the public sector (n = 4,365) who participated in the rehabilitation programme between 1996 and 2009.

Methods: The changes in annual purchases of prescribed pain medication were measured for a 9-year exposure window, starting from 4 years before the start date of rehabilitation and ending 5 years after this date.

Results: Purchases of prescribed pain medication increased throughout the follow-up in all medication groups. The steepest increase was observed for analgesics, antidepressants, and hypnotics and sedatives. The growth rate of annual purchase,  however, slowed significantly following the year of the start of rehabilitation for analgesics (annual growth rate (rate ratio) before and after rehabilitation 1.27 and 1.04, respectively, difference in trend p < 0.001); antidepressants (rate ratio 1.17 and 1.09, p = 0.005); and muscle relaxants (rate ratio 1.31 and 1.01, p < 0.001). For anxiolytics, and hypnotics and sedatives, no differences were observed in the trends of annual purchase before and after rehabilitation.

Conclusion: Rehabilitation was associated with a slowing increase in purchases of prescribed pain medication amongst rehabilitants. This may be a reflection of the positive effect that rehabilitation has on the need for pain medication.