The cost effectiveness of chlorofluorocarbon-free beclomethasone dipropionate in the treatment of chronic asthma: a cost model based on a 1-year pragmatic, randomised clinical study.

Abstract

To compare the cost effectiveness of hydrofluoroalkane 134a-beclomethasone dipropionate (HFA-BDP; Qvar) [corrected] with chlorofluorocarbon-beclomethasone dipropionate (CFC-BDP) in patients with chronic stable asthma previously receiving CFC-BDP, from the perspective of a healthcare provider. Cost-effectiveness analysis based on a 12-month pragmatic, randomised, parallel group, open-label clinical trial assessing safety and efficacy of HFA-BDP at approximately half the dose of CFC-BDP in patients with stable asthma. International, multicentre study at 57 study sites in the US, UK, The Netherlands, and Belgium. Healthcare costs were calculated for UK-based healthcare [in 1999 as pounds (pounds sterling)]. Patients (n = 473) > or =12 years of age with currently stable asthma that had been stable (i.e. no exacerbations requiring oral corticosteroid use in the last 4 weeks) for at least the preceding month. Average and incremental cost-effectiveness ratios based upon symptom-free days, improvement in health-related quality of life, and total and drug-only direct healthcare costs. Patients in the HFA-BDP group experienced a significantly higher percentage of symptom-free days than patients in the CFC-BDP group by the end of the study period (42.4 vs 20.0%; p = 0.006). A greater percentage of patients in the HFA-BDP group had a clinically significant improvement in health-related quality of life than in the CFC-BDP group [35.3 (n = 116/329) vs 16.1% (n = 18/112)]. Total per patient healthcare costs were similar between the two groups. The average cost per symptom-free day per patient was 1.36 pounds sterling for HFA-BDP and 1.81 pounds sterling for CFC-BDP based on total healthcare costs. The incremental cost per symptom-free day for using HFA-BDP instead of CFC-BDP was negative, indicating that HFA-BDP is a dominant strategy and may be a cost-saving intervention compared with CFC-BDP. A sensitivity analysis varying both cost and outcome parameters further supported this finding for most scenarios tested. The cost to achieve a clinically significant improvement in health-related quality of life over the study period was 13.24 pounds sterling per improved patient per week for HFA-BDP and 29.38 pounds sterling per patient per week for CFC-BDP. These findings indicate that HFA-BDP is a cost-effective intervention when compared with CFC-BDP in this group of patients with stable asthma. In the majority of scenarios HFA-BDP provides more effective asthma control at a similar cost to CFC-BDP.