title: Cost-effectiveness of dutasteride-tamsulosin combination therapy for the treatment of symptomatic benign prostatic hyperplasia: A Canadian model based on the CombAT trial.
abstract: BACKGROUND
  Benign prostatic hyperplasia (BPH) is common in men 50 years old and older. The main treatment options are alpha-blockers (such as tamsulosin), which reduce symptoms, and 5-alpha reductase inhibitors (such as dutasteride), which reduce symptoms and slow disease progression. Clinical studies have demonstrated that dutasteride-tamsulosin combination therapy is more effective than either monotherapy to treat symptomatic BPH. We studied the cost-effectiveness in Canada of the dutasteride (0.5 mg/day) and tamsulosin (0.4 mg/day) combination compared with tamsulosin or dutasteride monotherapy.
  
  
  METHODS
  A Markov model was developed which follows a cohort of male BPH patients ≥50 with moderate to severe lower urinary tract symptoms (LUTS). The model estimates costs to the Canadian health care system and outcomes (in terms of quality adjusted life years [QALYs]) at 10 years and over a patient's lifetime. The dutasteride-tamsulosin combination was compared to each of tamsulosin monotherapy and dutasteride monotherapy.
  
  
  RESULTS
  Compared with tamsulosin, the combination was more costly and produced better patient outcomes. Over a lifetime, the incremental cost-effectiveness ratio was CAN$25 437 per QALY gained. At a willingness to pay CAN$50 000 per QALY, the probability of combination therapy being cost-effective was 99.6%. Compared with dutasteride, the combination therapy was the dominant option from year 2, offering improved patient outcomes at lower cost. The probability that combination therapy is more cost-effective than dutasteride was 99.8%.
  
  
  CONCLUSIONS
  Combination therapy offers important clinical benefits for patients with symptomatic BPH, and there is a high probability that it is cost-effective in the Canadian health care system relative to either monotherapy.
authors.affiliation: Medical Affairs, GlaxoSmithKline Canada, Mississauga, ON; ; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON;
authors.forename: Afisi
authors.initials: A
authors.lastname: Ismaila
authors.forename: Anna
authors.initials: A
authors.lastname: Walker
authors.forename: Amyn
authors.initials: A
authors.lastname: Sayani
authors.forename: Bruno
authors.initials: B
authors.lastname: Laroche
authors.forename: J Curtis
authors.initials: JC
authors.lastname: Nickel
authors.forename: John
authors.initials: J
authors.lastname: Posnett
authors.forename: Zhen
authors.initials: Z
authors.lastname: Su