Although clinical trials demonstrate 5 alpha-reductase inhibitors (5ARIs) are efficacious treatments for benign prostatic hyperplasia (BPH), 5ARIs have low reported medication adherence outside of clinical trials. We evaluate real-world drug adherence and clinical outcomes in Medicare patients with lower urinary tract symptoms from BPH managed with 5ARI therapy.
Using healthcare and pharmacy claims from Partners Healthcare Medicare Accountable Care Organization enrollees (January 2009 – July 2018), we identify men initiating a 5ARI for BPH with more than one medication dispensation. Adherence was calculated as ≥80% proportion of days covered. A Cox proportional hazards model was used to evaluate the primary outcome of treatment failure, defined as any BPH-related surgery.
Among 3,107 men initiating 5ARI therapy for BPH and filling at least two prescriptions, 74.9% had high medication adherence over the first year. Patients with low adherence had 29% higher hazards of undergoing surgical intervention (95% confidence interval [CI]: 1.02–1.59, p = 0.036) after adjusting for age, BPH severity, the presence of hematuria, bladder stones, and type of 5ARIs. The presence of bladder stones (hazard ratio [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, 5ARI treatment adherence was high and associated with lower hazards of surgical intervention. 5ARI therapy may be more feasible for older men with BPH than previously reported and demonstrates modest clinical benefit.