A Pharmacoeconomic Analysis of Patients with Symptoms of Benign Prostatic Hyperplasia

Abstract

A pharmacoeconomic analysis of therapies for patients with benign prostatic hyperplasia (BPH) was conducted. The therapies compared were androgenic hormone inhibition (finasteride) and alpha-blockade (doxazosin, prazosin and terazosin). This was a cost-effectiveness analysis from the perspective of the US military. The 36-month decision-tree model considered the aforementioned drugs as initial therapy for BPH following an unsuccessful period of watchful waiting. Therapy was continued toward a successful response. All patients who did not respond to therapy received secondary interventions, including transurethral resection of the prostate (TURP). The main outcome measures were clinical effectiveness and incurred costs. A Monte Carlo sensitivity analysis was performed on all cost-effectiveness ratios. The model and sensitivity analysis supported prazosin as the most cost effective alpha-blocker over finasteride: the mean difference was $US381.65 (1994 values) per successfully treated patient, with a range of $US57.83 to $US675.53, in favour of prazosin. If prazosin was used as initial drug therapy after watchful waiting for a man over 50 years of age with classical symptoms of prostatism and no other severe or confounding comorbid conditions, a cost of $US578.15 per treatment could be expected, with clinical effectiveness of 70.3%. Patients who cannot tolerate prazosin should be considered for terazosin therapy before moving on from alpha-blockers. Subsequent treatment with finasteride would cost $US1426.53, with an additional clinical effectiveness of 9.9%. For the small number of patients who fail both therapies, the cost effectiveness of a first TURP as 'third-line' intervention [$US4321.36 for an additional effectiveness of 8.62% and a repeat TURP as 'fourth-line' ($US7650.54 for 0.59%) interventional] was calculated in a similar manner. Costs were cumulative, and effectiveness was derived from the total number of patients who started prazosin therapy. Pharmacological therapy was more cost effective than surgical intervention, and alpha-blockers were more cost effective than finasteride. Among the alpha-blockers, prazosin was by far the most cost effective followed by terazosin, then doxazosin.

Cost-Effectiveness of Tamsulosin, Doxazosin, and Terazosin in the Treatment of Benign Prostatic Hyperplasia

“…If the new therapy is successful at the end of a 12-month period, the patient remains on the new therapy. This 12-month (versus 6-month) window follows Cockrum et al 13 and is based on the slower onset of effect for finasteride compared with α-blockers. If the new (monotherapy or combination) drug therapy fails, the patient then progresses to TURP.…”

“…13 In the model, patients were started on drug therapy only after failing an initial period of watchful waiting. Patients who failed the initial medical therapy were assumed to switch to an alternative medication with up to 2 TURP procedures as needed to maintain treatment success.…”

“…Patients who initiate therapy with doxazosin are assumed to begin with 4 mg for 10 days and then go to 8 mg per day thereafter. These titration schedules are more rapid and entail fewer steps than in most previously published models (e.g., Cockrum et al 13 ), as these less conservative titration schedules are more likely to be consistent with usual practice (based on clinical judgment [Chrischilles and Kreder]). In contrast, patients initiating therapy with tamsulosin are assumed to take 0.4 mg once daily with no titration in the base-case model.…”

“…Estimates of unit costs for various resources used in the treatment of BPH were obtained from the literature, primarily as summarized by Cockrum et al 13 and Ackerman et al 24 Estimates of rates of complications for TURP were obtained from several sources, 12,[25][26][27][28] as noted in Table 1. The estimated cost for TURP used in the base case is an incidence-rate weighted average of costs associated with various surgical complications of TURP.…”

Photoselective vaporization of the prostate. Review of cost implementation to BPH treatment

“…17,18 However, surgery has been shown to be more cost effective than pharmaceuticals in the longterm because of the annual maintenance costs of oral medication. 19,20 In the short term, minimally invasive surgical therapies such as TUMT have been shown to be less expensive and as effective or less effective than TURP.…”