Purpose: To evaluate and compare real world cost-effectiveness of inhaled corticosteroids (ICS) administered by metered dose inhaler (MDI), breath-actuated MDI (BAI), or dry powder inhaler (DPI) in asthma.
Patients and methods: This retrospective database study analyzed the direct health care costs and proportion of patients (aged 5-60 years) achieving asthma control over 1 year in two population groups: those starting ICS (initiation population) and those receiving a first increase in ICS dose (step-up population). Asthma control was defined as no unplanned asthma visits, oral corticosteroids, or antibiotics for lower respiratory infection; outcomes were adjusted for confounding variables. Cost-effectiveness of BAI and DPI were compared with MDI.
Results: For the initiation population (n = 56,347), average annual health care costs per person (adjusted results), as compared with MDIs, were £9 higher (95% CI: -1.65 to 19.71) for BAIs and £32 higher (95% CI: 19.51 to 43.66) for DPIs. The probability of BAIs being the dominant strategy (more effective and less costly than MDIs) was 5% and of BAIs being more effective and more costly than MDIs was 94%. DPIs were consistently more effective and more costly than MDIs, with an incremental cost-effectiveness ratio of £1711 (95% CI: 760 to 3,576) per additional controlled patient per year. For the step-up population (n = 9169), mean total health care costs per person, (adjusted) as compared with MDIs, were £1 higher (95% CI: -27.28 to 31.55) for BAIs and £73 higher (95% CI: 44.48 to 103.29) for DPIs. The probability of BAIs being dominant was 48% and of BAIs being more effective but more costly than MDIs was 52%; the probability of DPIs being more effective but more costly than MDIs was 96%.
Conclusion: The real world effectiveness of ICS inhalers may vary, and inhaler device selection for patients with asthma should take into consideration not only initial device cost but also the subsequent health care resource costs.
Keywords: asthma control; breath-actuated inhaler; dry powder inhaler; incremental cost-effectiveness ratio; metered dose inhaler.