Long‐term risk of benign prostatic hyperplasia‐related surgery and acute urinary retention in men treated with 5‐alpha reductase inhibitor versus alpha‐blocker monotherapy in routine clinical care

OBJECTIVES: To assess the risk of benign prostatic hyperplasia (BPH)-related surgery and acute urinary retention (AUR) in men treated with 5-alpha-reductase inhibitor (5-ARI) versus alpha-blocker monotherapy in routine clinical care over 15 years of follow-up. METHODS: Using population-based Danish Health registries, we identified all new-users of 5-ARI or alpha-blocker monotherapy in Denmark, 1997-2017. We defined an index date 180 days after the date of first prescription and included men who redeemed at least one additional prescription before the index date. We used multiple imputation to replace missing prostate-specific antigen values. We performed propensity score-weighted Cox regression to estimate weighted hazard ratios (wHRs) and cumulative incidence function to estimate weighted cumulative risks of BPH-related surgery and AUR in intention to treat (ITT) and per protocol (PP) analyses. RESULTS: We included 18,421 and 95,984 men treated with 5-ARI and alpha-blocker monotherapy, respectively. Overall, treatment with 5-ARI monotherapy was associated with a reduced risk of BPH-related surgery (ITT wHR = 0.73 (95% confidence interval [CI]: 0.68-0.78), PP wHR = 0.77 (95% CI: 0.70-0.84) and AUR (ITT wHR = 0.73 (95% CI: 0.67-0.78), PP wHR = 0.75 (95% CI: 0.66-0.84). The 15-year risk of BPH-related surgery in men treated with 5-ARI versus alpha-blocker monotherapy was 14.8% (95% CI: 14.1%-15.5%) versus 19.1% (95% CI: 18.7%-19.5%) in the ITT analysis and 13.8% (95% CI: 12.6%-14.9%) versus 17.5% (95% CI: 16.9%-18.0%) in the PP analysis. The 15-year risk of AUR in men treated with 5-ARI versus alpha-blocker was 13.0% (95% CI: 12.3%-13.6%) versus 16.6% (95% CI: 16.3%-17.0%) in the ITT analysis and 12.6% (95%: 11.3%-14.0%) versus 16.9% (95% CI: 16.3%-17.6%) in the PP analysis. CONCLUSION: Treatment with 5-ARI versus alpha-blocker monotherapy in routine clinical care was associated with a reduced risk of BPH-related surgery and AUR for up to 15 years of follow-up. After 15 years of follow-up, the relative risk reduction was 21%-25% and the absolute risk reduction was 4%.