Objectives: To compare changes in medication use and costs over time for management of painful diabetic peripheral neuropathy (pDPN) or postherpetic neuralgia (PHN) among patients in commercial health plans requiring prior authorization (PA) for pregabalin versus patients in plans without pregabalin PA policies.
Study design: Retrospective claims data were obtained for 2005 to 2007 from 6 health plans with pregabalin PA and 6 health plans without pregabalin PA. Differences in resource utilization and costs were compared between baseline and 1-year follow-up periods using a pre-post parallel-group design.
Methods: Adults diagnosed as having pDPN or PHN with at least 1 claim for pDPN- or PHN-specific pain medication were selected. Pharmacologic therapy, healthcare utilization, and expenditures were analyzed using bivariate statistics and generalized linear models via a difference-in-differences approach comparing cohorts year over year.
Results: The 2 cohorts included 2084 patients in PA plans and 1320 patients in non-PA plans. Compared with non-PA plans, plans requiring PA experienced a 5.0-percentage point lower increase in patients using pregabalin year over year (P <.001). Utilization in PA plans of other anticonvulsants was 3.7 percentage points higher (P = .03), while nonopioid analgesic use was 5.2 percentage points lower (P = .01). There were no significant differences in opioid, antidepressant, or other pDPN or PHN medication use or pDPNor PHN-related total healthcare costs.
Conclusion: A PA policy for pregabalin was associated with lower pregabalin utilization, but there was no statistically significant effect on pDPN- or PHN-specific medication or healthcare expenditures.