Comparing Clinical and Economic Outcomes Associated with Early Initiation of Combination Therapy of an Alpha Blocker and Dutasteride or Finasteride in Men with Benign Prostatic Hyperplasia in the United States

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common disease in men that is characterized by lower urinary tract symptoms. Pharmacologic treatment with alpha blockers (ABs) and 5-alpha reductase inhibitors (5AR1s) is recommended to alleviate symptoms, prevent disease progression that can lead to complications, and reduce health care costs. OBJECTIVE: To compare clinical, economic, and health care resource utilization outcomes among BPH patients treated with early continuous combination AB and 5ARI therapy (dutasteride vs. finasteride) using administrative claims data from the United States. METHODS: A retrospective analysis of administrative claims data from 2003-2013 was conducted to compare outcomes between patients with claims for early combination therapy with dutasteride +AB and patients with claims for early finasteride +AB. The study population included males aged older than 50 years with at least 1 medical claim with a diagnosis of BPH and pharmacy dispensing for AB and 5ARI therapies. Outcomes included acute urinary retention (AUR), prostate-related surgery, clinical progression, medical and pharmacy costs, and health care resource utilization. Inverse probability of treatment (IPT) weighted Cox proportional hazards, linear, and Poisson regression models were used to assess the association between outcomes and early combination therapy as appropriate. RESULTS: A total of 2,778 patients were included in the early finasteride + AB treatment cohort, and 4,125 patients were included in the early dutasteride +AB cohort. Dutasteride users were younger than finasteride users (mean age: 64.8 vs. 67.5 years, P<0.001) and had a greater mean number of urologist visits (10.7 vs. 7.9, P<0.001) during baseline. After adjusting for confounding using IPT weighting, no statistically significant difference was observed between dutasteride and finasteride for AUR (hazard ratio [HR] =0.845, 95% CI = 0.660-1.070, P = 0.1643), prostate-related surgery (HR=0.806, 95% CI = 0.568-1.171, P=0.2525), and clinical progression (HR =0.834, 95% C1=0.663-1.043, P=0.1122). While dutasteride was associated with higher pharmacy costs per month (adjusted monthly cost difference=$79, 95% CI =$45-$105), total all-cause medical costs were not significantly different between the 2 cohorts (adjusted monthly cost difference = -$44, 95% C1=-$110-$22). CONCLUSIONS: Clinical and economic outcomes were similar between the early dutasteride +AB and early finasteride +AB cohorts, with no statistically significant differences detected. Copyright (C) 2016, Academy of Managed Care Pharmacy. All rights reserved.