Cost-Effectiveness Analysis of Formoterol Versus Salmeterol in Patients with Asthma
Objective: The aim of this study was to determine the relative economic consequences of treating asthmatics with twice daily dry powder formoterol 12µg as compared with salmeterol 50µg from a societal perspective. Design and Setting: A randomised, 6-month, open-label study including 482 patients with asthma was conducted in Italy, Spain, France, Switzerland, the UK and Sweden. Medical costs included the costs of medications, physician services, emergency room visits, hospital admissions and lung function and other tests. Travel costs and costs of production loss were also calculated. Unit prices were estimated from external sources. To pool the costs of the 6 countries, European currencies were converted to US dollars using 1995 exchange rates. Outcome measures were the number of episode-free days (EFDs) and the number of patients reaching a clinically relevant improvement in quality of life as measured using the St. Georges Respiratory Questionnaire. Main outcome measures and results: There were no significant differences between the 2 treatment arms in the frequency of emergency room visits, hospital admissions, use of rescue medication or contacts with general practitioners (GPs), specialists or nurses. Median medical costs over 6 months were $US828 per patient with formoterol and $US850 with salmeterol. This difference was not statistically significant. In both groups, about 60% of all days were episode-free. Average costs per EFD were about $US9 for both treatments. The average cost per patient reaching a clinically relevant improvement in quality of life was between $US1300 and $US1400. Incremental cost-effectiveness ratios were not calculated because both costs and outcomes were not significantly different. Asthma-related absenteeism ranged between 3 days and 6 months per patient in both groups. Conclusions: There was no evidence to suggest that either treatment was more cost effective than the other.