Changes in Pregabalin Dispensing to Australians with Workers' Compensation Claims for Low Back Pain Following the Listing of Pregabalin on the Pharmaceutical Benefits Scheme.

Objectives: We sought to identify whether the inclusion of pregabalin on the list of medicines subsidised by the Australian government in 2013 resulted in changes to the dispensing of pregabalin to Australians with workers' compensation claims for low back pain.

Methods: Using a sample of workers' compensation claims and payments data (2010-2018), we measured the prevalence of pregabalin dispensing and time to first pregabalin dispensing in workers whose claim began before, during or after pregabalin was listed on the Pharmaceutical Benefits Scheme (PBS) with binary logistic and Cox proportional hazards models. We used interrupted time-series analyses to measure changes in the monthly number, percentage of pain medicines, percentage of gabapentinoid dispensings, and median cost per dispensing of pregabalin.

Results: Of the 17,689 workers included in the study, 13.7% (n = 2431) were dispensed pregabalin during the study period. Workers in the groups whose claim occurred before or during when pregabalin was listed on the PBS were at significantly lower odds of being dispensed pregabalin than the group whose claim began after PBS listing (OR 0.20, 99% CI 0.15, 0.25 and OR 0.40, 99% CI 0.33, 0.48, respectively). There were significant step increases in the number of pregabalin dispensings (26.3%, 99% CI 6.2%, 50.3%), percentage of pain medicines that were pregabalin (29.3%, 99% CI 1.5%, 64.9%), and percentage of gabapentinoid dispensings that were pregabalin (13.9%, 99% CI 7.5%, 20.6%). There was a significant step decrease in the median cost per pregabalin dispensing (- 61.8%, 99% CI - 66.8%, - 56.1%).

Conclusion: Listing pregabalin on the PBS saw significant increases in the prevalence, number and percentage of pain medicines, and significant decreases in time to first pregabalin dispensing and cost.