Chronic obstructive pulmonary disease (COPD) is one of the most common diseases in the United States, and it has a significant medical and financial impact on the health care system. Current projections show that COPD-related morbidity and mortality will increase rapidly over the next 20 years. The results of multiple studies show that inhaled corticosteroids have a positive influence on airway responsiveness, reduce exacerbations, and slow the normal decline in health status for patients with COPD. Sin and associates evaluated the cost effectiveness of inhaled corticosteroids in patients with COPD to determine which patient groups should receive this class of medication.

The study design was a cost analysis using an established model that reviewed the effectiveness of four strategies for the use of inhaled corticosteroids in the treatment of COPD. These four strategies included: (1) no use in all stages of disease, (2) use in all stages, (3) use in patients with stage 2 or 3 disease, and (4) use only in those with stage 3 disease. Stage 2 disease is defined as a forced expiratory volume in one second (FEV₁) of 35 to 50 percent of predicted, while stage 3 is anFEV₁ of less than 35 percent of predicted. The authors used published data to estimate mortality, exacerbations, and disease progression rates using the four strategies and examined the cost associated with care of COPD patients and quality-adjusted life-years (QALYs). They used a time model that evaluated this feature over a three-year time period.

The sample of patients used in the model had a mean age of 61; 21 percent were women, 87 percent were white, 97 percent were current or former smokers, 40 percent were current smokers, and there was a total of 54 pack-years of smoking. The total marginal cost over three years of inhaled corticosteroids if given only to patients in stage 2 or 3 of the disease would be $922 per person. If inhaled corticosteroids were given to all patients with COPD, the cost would be $3,612 per person. If corticosteroids were given only to those with stage 3 disease, the total marginal cost would be $774.

If corticosteroids were given only to those with stage 2 or 3 disease, the cost was $17,000 per QALY gained. If this treatment was reserved for those in stage 3 disease, the cost was $11,100 per QALY gained. If inhaled corticosteroids were given to all patients with COPD, regardless of disease severity, the cost was $46,200 per QALY gained. Using a benchmark of $50,000 per QALY gained, there would be a 57 percent probability that the strategy to provide this therapy to all patients with COPD would be effective. Using the same benchmark, the probability increased to 95 percent in patients with stage 2 or 3 disease and to 84 percent in those with stage 3 disease.

The authors conclude that using inhaled corticosteroids in patients with COPD patients at stages 2 and 3 is cost effective, and the cost is similar to that of other common treatments. They add that patients with increased disease severity may benefit from this treatment strategy.