Overactive bladder medication: Anticholinergics versus mirabegron by specialty.

Purpose: The primary aim of this study was to identify high prescribing specialties of overactive bladder (OAB) medications for Medicare Part D beneficiaries, and describe prescribing trends by specialty from 2013 to 2017. The secondary aim was to compare the proportion of medication claims by medication class in each specialty.
Methods: We used the Medicare Part D Provider Public Use File to identify the four highest prescribing specialties from 2013 to 2017. We then compared patterns of OAB medication prescription for beneficiaries over 65 years of age between specialties. The number of medication claims, cost, and region were considered. OAB medications were classified as anticholinergic or mirabegron for additional comparison. The primary outcome was the number of OAB medication claims, and the secondary outcome was the proportion of mirabegron claims of all medication claims.
Results: Primary care providers (PCPs), urology, obstetrics and gynecology (OB/GYNs), and other specialties prescribed the most OAB medications. Total claims increased from 4.06 million in 2013 to 4.51 million in 2017. Mirabegron increased from 65,520 to 892,996 claims. PCPs prescribed the most OAB medications. Urologists had the highest proportion of mirabegron prescribing (19.6%), with an increased odds of mirabegron prescribing compared to OBGYNs (aOR 1.18, 95% CI 1.16-1.19). Compared to OBGYNs, PCPs, and other specialties demonstrated decreased odds of prescribing mirabegron (aOR 0.92 with 95% CI 0.91-0.93, and aOR 0.90 with 95% CI 0.88-0.91, respectively).
Conclusion: In Medicare Part D beneficiaries, PCPs prescribed the most OAB medications between 2013 and 2017. Urologists were most likely to prescribe mirabegron.