Cost-effectiveness of combination therapy for chronic obstructive pulmonary disease.

ABSTRACT

BACKGROUND: There is evidence that combination therapy (CT) in the form of long-acting beta(2)-agonists (LABAs) and inhaled corticosteroids can improve lung function for patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To determine the cost-effectiveness of using CT in none, all or a selected group of COPD patients. METHODS: A Markov model was designed to compare four treatment strategies no use of CT regardless of COPD severity (patients receive LABA only); use of CT in patients with stage 3 disease only (forced expiratory volume in 1 s [FEV(1)] less than 35% of predicted); use of CT in patients with stages 2 and 3 disease only (FEV(1) less than 50% of predicted); and use of CT in all patients regardless of severity of COPD. Estimates of mortality, exacerbation and disease progression rates, quality- adjusted life years (QALYs) and costs were derived from the literature. Three-year and lifetime time horizons were used. The analysis was conducted from a health systems perspective. RESULTS: CT was associated with a cost of $39,000 per QALY if given to patients with stage 3 disease, $47,500 per QALY if given to patients with stages 2 and 3 disease, and $450,333 per QALY if given to all COPD patients. Results were robust to various assumptions tested in a Monte Carlo simulation. CONCLUSION: Providing CT for COPD patients in stage 2 or 3 disease is cost-effective. The message to family physicians and specialists is that as FEV(1) worsens and reaches 50% of predicted values, CT is recommended.