Accuracy of Accuhaler, Ellipta, and Turbuhaler Testers in Patients with Chronic Obstructive Pulmonary Disease

<b>Background</b>: Peak inspiratory flow rate (PIFR) measurement is an essential tool for assessing the effectiveness of inhaler therapy in chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the accuracy of three different inhaler testers compared to the In-Check DIAL^® device. <b>Methods</b>: A cross-sectional study was conducted in clinically stable COPD patients. Participants performed PIFR measurements using the In-Check DIAL^® device and three inhaler testers (Accuhaler, Ellipta, and Turbuhaler). Optimal PIFR was defined as ≥60 L/min. Minimum PIFR was defined as ≥30 L/min. <b>Results</b>: A total of 82 COPD patients (93.9% male) were included, with a mean age of 73.3 ± 8.8 years. Post-bronchodilator forced expiratory volume in one second was 69.2 ± 21.0%. The prevalence of optimal PIFR was 78%, 74%, and 52% for the Accuhaler, Ellipta, and Turbuhaler testers, respectively. For detecting optimal PIFR, the Accuhaler tester demonstrated an accuracy of 80.5%, sensitivity of 100%, and specificity of 11.1%. The Ellipta tester showed an accuracy of 78.1%, sensitivity of 100%, and specificity of 14.3%, while the Turbuhaler tester achieved an accuracy of 56.1%, sensitivity of 100%, and specificity of 7.7%. All devices showed excellent accuracy (>95%), sensitivity (>98%), and specificity (100% except for the Turbuhaler tester) in detecting minimum PIFR. <b>Conclusions</b>: The majority of COPD patients achieved optimal PIFR across the three different devices, with the highest prevalence observed for the Accuhaler tester. All three inhaler testers demonstrated excellent accuracy in assessing PIFR in COPD patients, suggesting their potential as reliable alternatives to the In-Check DIAL^® device in clinical practice.