A randomized crossover study assessing critical errors and preferences of two commonly used multi-dose dry-powder inhalers

<bold>Background:</bold> The effectiveness of inhaled medications in asthma and COPD is significantly impacted by compliance to prescribed regimens. The design of the inhalation device plays a crucial role. The [NEXThaler], with its triple feedback mechanism, enables users to verify correct inhalation technique, compared to a low-feedback inhaler [Turbuhaler]. <bold>Methods:</bold> In this open-label, randomised cross-over study, the proportions of asthma and COPD patients making critical errors were compared between the [NEXThaler] and [Turbuhaler] after 4 weeks of clinical use. All patients were thoroughly instructed in the use of the inhalers. Also, preference was investigated. <bold>Results:</bold> 90 asthma and 49 COPD patients were included. After 4 weeks of use, no significant difference (p=0.73) was found in critical error rates between the two inhalers (Table). However, more patients preferred the NEXThaler (57.6%) over the Turbuhaler (34.5%) with 7.9% indicating no preference (p=0.006). Also, on most sub-items, NEXThaler was preferred. See figure. <table-wrap><object-id>erj;64/suppl_68/PA746/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td>Turbuhaler >=1 critical error</td><td>Turbuhaler no critical error</td></tr><tr><td>NEXThaler >=1 critical error</td><td>0</td><td>3</td></tr><tr><td>NEXThaler no critical error</td><td>5</td><td>131</td></tr></tbody></table></table-wrap> <fig><object-id>erj;64/suppl_68/PA746/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusions:</bold> Following a thorough instruction, very few errors were made, highlighting the importance of dedicating sufficient time to instruct patients in correct inhalation technique. The [NEXThaler] was generally preferred over [Turbuhaler].