Cost-effectiveness analyses of salmeterol/fluticasone propionate combination product and fluticasone propionate in patients with asthma I: Introduction and overview

When a new drug therapy is introduced, it is important to consider the econ omic impact of the treatment. This is particularly relevant for a chronic d isease such as asthma. Despite an increased understanding of the physiology of asthma, this condition remains an important cause of morbidity and mort ality in many countries and places a large financial burden on healthcare s ystems. An economic analysis was performed to determine the cost effectiveness of 3 strengths of a new salmeterol/fluticasone propionate combination product ( SFC): 50/100, 50/250 and 50/500 mu g twice daily relative to the equivalent dose of fluticasone propionate (FP) alone (100, 250 or 500 mu\g twice dail y, respectively). The economic analysis was performed using 12-week data fr om 3 randomised controlled clinical trials in adults and adolescents with a sthma. The analysis was conducted from the perspective of the Swedish healt hcare system and only direct costs were considered. Data from daily diaries showed that all 3 strengths of SFC were associated with a significantly hi gher proportion of successfully treated weeks (defined as a greater than or equal to 5% improvement in predicted peak expiratory flow, compared with b aseline) than FP alone. The cost per successfully treated week was lower fo r all 3 strengths of the combination product than for the equivalent dose o f FP alone [SEK150.9 to 365.1 ($US18.31 to 44.30) vs SEK169.0 to 487.8 ($US 20.50 to 59.18)], despite higher drug costs associated with the former. The incremental cost-effectiveness ratios showed that the costs to achieve an additional successfully treated week with SFC were SEK133.4 ($US16.18), SEK 12.6 ($US1.53) and SEK192.1 ($US23.31) for the 50/100, 50/250 and 50/500 mu g strengths, respectively. Sensitivity analysis indicated that these resul ts were robust over a wide range of assumptions. Thus, in the Swedish healt hcare setting SFC 50/100, 50/250 and 50/500 mu g are more cost effective th an the equivalent doses of FP alone in patients with asthma.