High Real-World Medication Adherence and Durable Clinical Benefit in Medicare Patients Treated with 5-Alpha Reductase Inhibitors for Benign Prostatic Hyperplasia.

Abstract

Although clinical trials demonstrate 5-alpha reductase inhibitors are efficacious treatments for benign prostatic hyperplasia, they have low reported medication adherence outside of clinical trials. We evaluated real-world drug adherence and clinical outcomes in Medicare patients with lower urinary tract symptoms from benign prostatic hyperplasia managed with 5-alpha reductase inhibitor therapy. Using health care and pharmacy claims from Partners Healthcare Medicare Accountable Care Organization enrollees (January 2009 to July 2018), we identified men initiating a 5-alpha reductase inhibitor for benign prostatic hyperplasia with more than 1 medication dispensation. Adherence was calculated as an 80% or greater proportion of days covered. A Cox proportional hazards model was used to evaluate the primary outcome of treatment failure, defined as any benign prostatic hyperplasia related surgery. Among 3,107 men initiating 5-alpha reductase inhibitor therapy for benign prostatic hyperplasia and filling at least 2 prescriptions, 74.9% had high medication adherence during the first year. Patients with low adherence had 29% higher hazards of undergoing surgical intervention (95% CI 1.02-1.59, p=0.036) after adjusting for age, benign prostatic hyperplasia severity, presence of hematuria, bladder stones and type of 5-alpha reductase inhibitors. The presence of bladder stones (HR 1.70, 95% CI 1.02-2.86, p=0.04) and finasteride vs dutasteride use (HR 1.41, 95% CI 1.01-1.98, p=0.05) were also risk factors for surgical intervention. Among Medicare patients 5-alpha reductase inhibitor treatment adherence was high and associated with lower hazards of surgical intervention. 5-Alpha reductase inhibitor therapy may be more feasible for older men with benign prostatic hyperplasia than previously reported and demonstrates modest clinical benefit.