Device type and real-world effectiveness of asthma combination therapy: An observational study

Background: Selection of inhaler device type appears to influence real-world effectiveness of inhaled corticosteroids (ICS), but data are lacking on the role of inhaler device in ICS and long-acting beta 2-agonist (LABA) combination therapy for asthma. Methods: This retrospective matched cohort study compared 1-year asthma outcomes for UK patients initiating fixed-dose combination (FDC) fluticasone salmeterol delivered by pressurised metered-dose inhaler (pMDI) versus dry powder inhaler (DPI). Patients with asthma aged 4-80 years receiving a first prescription for FDC fluticasone salmeterol by pMDI or DPI were matched on baseline demographic and asthma severity measures. Co-primary outcomes were asthma control (a composite measure comprising no recorded hospital attendance for asthma, oral corticosteroids, or antibiotics for lower respiratory infection) and exacerbation rate. Results: Compared with the DPI cohort (n = 1567), patients in the pMDI cohort (n = 1567) had significantly greater odds of achieving asthma control during the outcome year (odds ratio [OR] 1.19; 95% confidence interval [CL] 1.01 to 1.40). Exacerbation rate was lower but not significantly in the pMDI cohort (adjusted rate ratio for pMDI cohort, 0.82; 95% CL 0.66 to 1.00). The odds of treatment success (defined as no exacerbations and no change in asthma therapy) was significantly greater in the pMDI cohort (OR 1.23; 95% Cl, 1.07 to 1.42). Conclusions: For UK primary care patients, pMDIs appear to achieve better asthma control outcomes than DPIs for delivery of FDC fluticasone salmeterol. Pragmatic trials are needed to further investigate real-world outcomes with different inhaler devices for combination therapy. (C) 2011 Elsevier Ltd. All rights reserved.