Risk Factors Associated with Misuse of Soft Mist Inhaler in Patients with Chronic Obstructive Pulmonary Disease

Purpose: The use of inhaled bronchodilators is the mainstay of treatment for patients with chronic obstructive pulmonary disease (COPD). Although the soft mist inhaler (SMI) was developed to overcome the disadvantages of pressurized metered dose and drug powder inhalers, misuse during handling has been frequently observed in many studies. However, few studies have focused on SMI misuse among patients with COPD. Thus, we aimed to assess and identify the risk factors associated with SMI misuse among patients with COPD. Patient and Methods: In this prospective, observational, cross-sectional study, we enrolled patients with COPD who were undergoing SMI treatment between January 2018 and March 2020. An advanced nurse practitioner assessed the participants' handling of the device by using a check list. Results: Among 159 participants, 136 (85.5%) reported inhaler misuse. Duration of COPD and COPD assessment test (CAT) scores were positively associated with inhaler misuse; adherence and education level were negatively associated with inhaler misuse. In the multivariable analysis, a low educational level (less than high school), high CAT score (≥ 10), and short duration of COPD (≤ 2 years) were identified as risk factors for SMI misuse. Conclusion: SMI misuse remains common among patients with COPD. Therefore, clinicians should pay close attention to their patients using SMIs, especially in the early period after the diagnosis of COPD. Keywords: chronic obstructive pulmonary disease, bronchodilators, misuse, soft mist inhaler