Misuse of inhalers among COPD patients in a community hospital in Taiwan.

Purpose: Respiratory inhalers, which directly deliver medication to the airway, are important for controlling symptoms and preventing exacerbations of chronic obstructive pulmonary disease (COPD). The inhaler misuse rate of patients with COPD in Taiwan is unclear. In this study, the inhaler techniques and patient characteristics associated with incorrect inhaler techniques among patients with COPD were evaluated.

Patients and methods: This cross-sectional study enrolled 298 patients with COPD (mean age 72.10 years) who used at least one inhaler device. The following five types of inhalers were included: metered-dose inhaler (MDI) with spacer, Diskus® , Turbuhaler® , Respimat® , and Breezhaler® . The inhaler technique was evaluated step by step. Misuse of an individual inhaler was defined as an error in at least one step. The sociodemographic characteristics, vision, hearing ability, type and number of inhalers, and inhaler-related knowledge of these patients were recorded.

Results: The misuse rates of the five types of inhalers ranged from 65.00% to 87.89%. The Respimat inhaler was the most likely to be assembled incorrectly. The steps that were most commonly performed incorrectly were "breathing out fully" and "holding breath". In the logistic regression analysis, poor hearing was related to misuse of the MDI with spacer (adjusted odds ratio [aOR] 9.85; 95% CI 1.40-69.30); the number of acute exacerbations was related to misuse of Breezhaler (aOR 4.07; 95% CI 1.50-11.08). Incorrect inhaler-related knowledge was significantly associated with misuse in handling the MDI with spacer (aOR 9.58; 95% CI 2.14-42.80), Respimat (aOR 5.14; 95% CI 2.07-12.76), and Breezhaler (aOR 6.98; 95% CI 1.95-25.08).

Conclusion: The misuse rates were high for all five types of inhaler. Poor hearing and the number of acute exacerbations were device-specific factors related to the misuse of inhalers. Inhaler-related knowledge was significantly associated with misuse, emphasizing the importance of inhaler education.