Prescription Dispensing Patterns Before and After a Workers' Compensation Claim: An Historical Cohort Study of Workers With Low Back Pain Injuries in British Columbia

Objective: Compare prescription dispensing before and after a work-related low back injury. Methods: Descriptive analyses were used to describe opioid, nonsteroidal anti-inflammatory drug (NSAID), and skeletal muscle relaxant (SMR) dispensing 1 year pre- and post-injury among 97,124 workers in British Columbia with new workers' compensation low back claims from 1998 to 2009. Results: Before injury, 19.7%, 21.2%, and 6.3% were dispensed opioids, NSAIDs, and SMRs, respectively, increasing to 39.0%, 50.2%, and 28.4% after. Median time to first postinjury prescription was less than a week. Dispensing was stable pre-injury, followed by a sharp increase within 8 weeks post-injury. Dispensing dropped thereafter, but remained elevated nearly a year post-injury, an increase attributable to less than 2% of claimants. Conclusion: These drug classes are commonly dispensed, particularly shortly after injury and dispensing is of short duration for most, though a small subgroup receives prolonged courses.