Background: Efficacy and safety data from clinical trials of inhalers have been pooled and reported in previous studies. However, data on the patient acceptability of delivery devices were not fully reported. Acceptability of inhaler devices may be an important factor in patient compliance with regular maintenance therapy.Objective: The purpose of this retrospective, combined analysis was to assess acceptability data as an outcome variable in 3 double-blind, double-dummy studies comparing a dry powder inhaler (DPI) with a metered-dose inhaler (MDI) for delivery of beclomethasone dipropionate (BDP) to adult and pediatric patients with asthma.Methods: Studies used in this analysis were conducted in adult and pediatric patients with asthma to assess the efficacy, safety, and acceptability of either DPI or MDI (with a spacer if considered appropriate by the investigator) as a BDP delivery method after an open-label run-in period of 2 to 4 weeks, during which all patients received BDP by MDI.Results: End-of-study questionnaires were completed by 94% of randomized patients (339/362). All 3 studies demonstrated statistical therapeutic equivalence and tolerability of the 2 devices. Patients assessed the acceptability of the DPI and the MDI after =<12 weeks of clinical use. Overall, significantly more patients found the DPI (67%) easier to use compared with the MDI (22%; P < 0.01). The DPI dose counter was rated useful by 82% of patients, and significantly more patients preferred the DPI (63%) to the MDI (28%; P < 0.01).Conclusions: This analysis of combined study data demonstrates that different delivery formats may have a marked effect on patient acceptability, and that patients in these studies preferred the delivery format of the DPI to that of the MDI, making compliance more likely.