Patient perception and acceptability of multidose dry powder inhalers:: A Randomized crossover comparison of Diskus/Accuhaler with Turbuhaler

This study was designed to provide information on correct use and preference to features and device handling of two multidose dry powder inhalers, the Diskus/Accuhaler(R) and the Turbuhaler(R). A total of 169 powder-naive patients (mean age 40 years) with asthma or chronic obstructive pulmonary disease (COPD) were enrolled in a randomized crossover comparison of both inhalers. An effective use of either inhaler was assessed before (leaflet only) and after inhaler education. Ease of use especially during an attack and the presence of a dose counter were regarded as the most important features for an ideal inhaler. The percentage of correct handling maneuvers and the percentage of patients achieving 100% of correct maneuvers increased significantly (p < 0.001) after inhaler education in both devices, but percentage of correct use after the intervention was significantly higher for the Diskus/Accuhaler (92.6%) than for the Turbuhaler (89.8%; P = 0.036). Overall 60% of patients thought the Diskus/Accuhaler was preferable to the Turbuhaler (p < 0.001). The main reasons given were presence of a dose counter, perceived ease of use including ease of learning to use, design, and attached cover. Among those who preferred the Turbuhaler device, the main reason cited was small size, discreetness, and ease of holding. In the multivariate analysis, inhaler education (p = 0.005) and education level (p = 0.009) were significantly associated with the percentage of correct maneuvers. Age, sex, or tested inhaler showed no effect on appropriateness of the inhalation technique.