INTRODUCTION AND OBJECTIVES: Overactive bladder (OAB) affects up to 40-50% of older men and women. OAB diminishes quality of life through its impact on daily living and emotional well-being, even in the absence of urine loss. The economic costs of treating patients with OAB are projected to exceed $80 billion annually by 2020, more than half incurred by Medicare beneficiaries. Despite this burden of disease, no prior study has examined pharmacotherapy prescribing patterns in the Medicare population. Our objective was to describe variation in initial drug treatment of OAB symptoms among Medicare Part D beneficiaries.METHODS: We performed a cross-sectional analysis of beneficiaries using the Medicare 5% sample. Between 2007-2013, we identified beneficiaries with an outpatient encounter consistent with OAB symptoms and a Medicare Part D drug claim for a first generation (pre-2000 FDA approval: oxybutynin, tolterodine) or a second generation (post-2000 FDA approval: darifenacin, fesoterodine, mirabegron, solifenacin, trospium) agent. Subjects with urinary tract infection within 30 days, neurogenic bladder, and prostate cancer diagnoses were excluded. No subject had a prior OAB drug claim. We used a multivariable log-binomial regression model to estimate the relative probability of receipt of an initial 2nd generation agent, controlling for beneficiary demographics, comorbidity, provider specialty, and geographic variation.RESULTS: During the study period, 17,944 beneficiaries had an initial drug claim. The average subject was aged 78 AE 7.5 years, 80% were female, and 89% were white. Beneficiaries dually eligible for Medicaid constituted 26% of the cohort. In multivariable models, black beneficiaries and dual-eligibles were slightly less likely to receive 2nd generation agents as first line therapy (black: RR 0.91, p¼0.015; Medicaid: RR 0.95, p¼0.012). Urologists and gynecologists were substantially more likely than generalists to prescribe 2nd generation drugs (urology: RR 1.49, p<0.001; gynecology: RR 1.30, p<0.001). Subjects with dementia were 13% (95% CI 6%-19%) more likely to receive a 2nd generation agent.CONCLUSIONS: Medicare beneficiaries initially treated by specialists are substantially more likely to receive 2nd generation OAB agents as first line therapy. While side effect profiles may differ, current guidelines do not support substantial efficacy differences among these agents. Further investigation is required to understand differences in outcomes and costs associated with these disparate prescribing patterns.Source of Funding: NIH/NIA GEMSSTAR program (R03AG048130) and American Geriatric Society Dennis W. Jahnigen Career Development Award (Scales).
