Geographic Variation in the Use of Gabapentinoids and Opioids for Pain in a Commercially Insured Adult Population in the United States
Background: Gabapentinoids have been prescribed off-label for almost all types of pain. The geographic variation in the use of gabapentinoids as analgesics remains unknown. Objective: To describe the geographic variation in gabapentinoids, opioids and concurrent use of both for pain by US state and metropolitan statistical area (MSA). Methods: We conducted a cross-sectional study on December 1, 2018, among commercially insured adults aged 18–64 years without epilepsy or opioid use disorders using IBM® MarketScan® Research Databases. We described the geographic variation in the analgesic regimens (gabapentinoids, opioids and concurrent use of both) by state and MSA, and assessed factors associated with the geographic variation using multilevel logistic regression. Results: We included 9,314,197 beneficiaries; 1.4% had gabapentinoids, 1.5% had opioids and 0.3% had concurrent use of both. The majority of gabapentinoid use lacked an FDA-approved indication. Use of the analgesic regimens varied across states (gabapentinoids (median (interquartile range)): 1.4% (1.2–1.7%); opioids: 1.5% (1.2–1.9%); both: 0.3% (0.2–0.4%)) and MSAs (gabapentinoids: 1.6% (1.3–2.0%); opioids: 1.8% (1.3–2.3%); both: 0.3% (0.2–0.5%)). Demographics explained the largest proportion of the between-state and between-MSA variation. The pattern of the geographic variation in gabapentinoids was similar to that of opioids across states and MSAs. Conclusion: Gabapentinoids were as commonly used as opioids for pain in a commercially insured population (mostly off-label). The geographic variation in gabapentinoids was similar to that of opioids, which suggests that gabapentinoids may be widely used as alternatives or adjuvants to opioids across the US.