Frailty, Specialized Care, and Sociodemographic Factors: Disparities in Oral Pharmacotherapy Class Utilization Among Medicare Part D Beneficiaries With Overactive Bladder in the United States

Abstract

Objective: To describe the prevalence of frailty among Medicare beneficiaries with overactive bladder (OAB), analyze oral therapy patterns, and examine potential disparities in treatment.

Methods: This retrospective cohort study utilized the 20% Research Identifiable File Medicare Part D prescription claims dataset (2013-2018). Using the Claims-Based Frailty Index (CFI), Medicare beneficiaries ≥65 years old with OAB were categorized as not frail (CFI <0.15), prefrail (0.15 ≤CFI<0.25), and frail (CFI >0.25). Logistic regression models assessed associations between frailty and pharmacotherapy utilization.

Results: Among 111,761 patients (15.8% of the OAB cohort) receiving oral pharmacotherapy (anticholinergic oral medications or mirabegron), 71% were women, 83% were White, and 11.9% were frail. After controlling for age, copayments and dual eligibility status, frail status (OR 1.16; 95% CI [1.09-1.24]), urology (OR 2.05; 95% CI [1.94-2.16]) or gynecology (OR 1.74; 95% CI [1.6-1.9]) prescribers and residing in the Southern United States (OR 1.53; CI [1.49-1.61]) were associated with higher likelihood of mirabegron utilization. Black (OR 0.79; 95% CI [0.74-0.85]) and American Indian/Alaska Native (OR 0.54; 95% CI [0.39-0.74]) patients were less likely to utilize Mirabegron than White beneficiaries.

Conclusion: Frail beneficiaries and those with urology and gynecology prescribers showed higher likelihoods of beta-3 agonist utilization. Despite adjustments, Black and American Indian/Alaskan Native patients were less likely to fill mirabegron prescriptions, suggesting disparities in treatment. Our findings highlight the need for policies, interventions, and initiatives to promote equitable OAB oral therapy utilization in vulnerable populations.