Prevalence of Critical Errors and Insufficient Peak Inspiratory Flow in Patients Hospitalized with COPD in a Department of General Internal Medicine: A Cross-Sectional Study.

Background: The suboptimal use of inhalers in the treatment of patients with chronic obstructive pulmonary disease (COPD) is probably a major but poorly documented problem in hospitalized patients. We aimed to describe the prevalence of misused inhalers among patients hospitalized with COPD in a department of general internal medicine.

Methods: We conducted a monocentric cross-sectional study in consecutive patients with a diagnosis of COPD and hospitalized between August 2022 and April 2023 in the internal medicine division of Fribourg Hospital, Switzerland. Patients underwent an assessment of their inhaler technique and peak inspiratory flow (PIF) using the In-Check Dial G16^®. The primary outcome was the prevalence of misused inhalers, defined as an inhaler used with a critical error and/or insufficient PIF. Secondary outcomes included the prevalence of inhalers unsuitable to patients' characteristics and of patients using at least one misused inhaler.

Results: The study included 96 patients and 160 inhalers were assessed at admission. Among these inhalers, 111 (69.4%; 95% confidence interval [CI] 61.6-76.4) were misused; 105 (65.6%; 95% CI 57.7-72.9) due to the presence of a critical error in the inhalation technique and 22 (13.8%; 95% CI 8.8-20.1) due to insufficient PIF. Concerning the secondary outcome, 27 inhalers (16.9%) were unsuitable, and 79 patients (82.3%) used at least one misused inhaler.

Conclusion: Among patients hospitalized with a diagnosis of COPD, two-thirds of inhalers were misused. Suboptimal use was mainly due to the presence of critical errors, but also to the presence of an insufficient PIF and unsuitable inhalers.