An economic evaluation of doxazosin, finasteride and combination therapy in the treatment of benign prostatic hyperplasia.
The Proscar Long-Term Efficacy and Safety Study (PLESS) and the Medical Therapy of Prostatic Symptoms (MTOPS) study provide new evidence regarding the benefits of finasteride in the treatment of benign prostatic hyperplasia (BPH). The objective of this study was to utilize data from the PLESS and MTOPS studies to assess the cost-utility of finasteride and finasteride in combination with doxazosin, compared to doxazosin alone in men with moderate to severe BPH symptoms. A semi-Markov decision analytic model was constructed to estimate the clinical consequences, costs and cost-utility of doxazosin, finasteride, and combination therapy. Analyses were conducted for a 15-year time frame from the perspective of the Ontario Ministry of Health and Long Term Care (MOHLTC). Results are reported stratified by baseline serum prostate-specific antigen (PSA) level according to all baseline serum PSA levels, patients with baseline serum PSA > 1.3 ng/ml, and patients with baseline serum PSA > 3.2 ng/ml. Compared to doxazosin alone, combination therapy was more expensive but more effective. Cost-utility ratios ranged from 27,823 dollars/QALY for patients with PSA > 3.2 ng/ml to 34,085 dollars/QALY for all patients. Finasteride, although dominated by doxazosin, may be cost-effective compared to watchful waiting in patients who fail doxazosin and do not choose to proceed to surgery. Compared to watchful waiting, cost-utility ratios for finasteride ranged from 35016 dollars/QALY for patients with PSA > 3.2 ng/ml to 44,336 dollars/QALY for all patients. Results were robust across a wide range of sensitivity analyses. Combination therapy is cost-effective compared to doxazosin with cost-utility ratios under 40,000 dollars/QALY across a wide range of scenarios. The cost-effectiveness of combination therapy increases as serum PSA level increases.