A 12-Year Retrospective Study of the Prevalence of Anticholinergic Polypharmacy and Associated Outcomes Among Medicare Patients with Overactive Bladder in the USA

Abstract

Background and objective: Antimuscarinics, drugs with anticholinergic properties, are frequently prescribed for overactive bladder, and anticholinergic burden is associated with adverse events. The "Polypharmacy: Use of Multiple Anticholinergic Medications in Older Adults" (Poly-ACH) measure was developed by the Pharmacy Quality Alliance and is used by the Centers for Medicare and Medicaid Services. Using the Poly-ACH measure, we assessed the prevalence of anticholinergic polypharmacy among Medicare patients in the USA with overactive bladder and determined associations between polypharmacy and medical conditions, care, and spending. Methods: This was a retrospective cohort study of Medicare beneficiaries with overactive bladder (coverage period: 2006-2017). Anticholinergic polypharmacy, measured by the Poly-ACH, was defined as concurrent use of two or more anticholinergics, each with two or more prescription claims on different dates of service for ≥ 30 cumulative days. Change in annual frequency of anticholinergic polypharmacy was assessed using logistic regression. Associations between anticholinergic polypharmacy over 3 years and falls, fractures, mental status, and medical care spending were assessed with longitudinal regression models. Results: In total, 226,712 patients contributed 940,201 person-years of follow-up after overactive bladder diagnosis. The share of patients meeting the Poly-ACH definition was 3.3% in 2006 and 1.7% in 2017. Women and nursing home residents had higher risks of anticholinergic polypharmacy. Having 1 year or more of positive Poly-ACH status in the 3 years prior was associated with higher rates of all outcomes. Conclusions: Anticholinergic polypharmacy was uncommon among older adults with overactive bladder. Prevalence was higher among women and nursing home residents, and it was associated with negative outcomes, highlighting potential longitudinal implications of anticholinergic burden.