Resource use, costs, and utility estimates for patients with cystic fibrosis with mild impairment in lung function: analysis of data collected alongside a 48-week multicenter clinical trial.

OBJECTIVES

Transport of ions to generate epithelial rehydration (TIGER)-1 was a randomized trial conducted to evaluate the safety and efficacy of denufosol versus placebo in patients with cystic fibrosis with mild impairment in lung function. The trial met its primary end point at 24 weeks, but a subsequent trial did not show a sustained effect of denufosol at 48 weeks. By using the 48-week data, we characterized resource use, direct medical costs, indirect costs, and utility estimates.

METHODS

Data on medications, outpatient and emergency visits, hospital admissions, tests, procedures, and home nursing were captured on study case report forms. Sources for unit costs included the Medicare Physician Fee Schedule, the Nationwide Inpatient Sample, and the Red Book. Health utilities were derived from the Health Utilities Index Mark 2/3. We used multivariable regression to evaluate the impact of baseline covariates on costs.

RESULTS

Characteristics of the 352 participants at enrollment included mean age of 14.6 years, history of Pseudomonas aeruginosa colonization in 45.2%, use of dornase alfa in 77.0%, and long-term use of inhaled antibiotics in 37.2%. Over 48 weeks, 22.4% of participants were hospitalized and, on average, participants missed 7.4 days of school or work. Mean total costs (excluding denufosol) were $39,673 (SD $26,842), of which 85% were attributable to medications. Female sex and P. aeruginosa colonization were independently associated with higher costs.

CONCLUSIONS

Prospective economic data collection alongside a clinical trial allows for robust estimates of cost of illness. The mean annual cost of care for patients with cystic fibrosis with mild impairment in lung function exceeds $43,000 and is driven by medication costs.