Assessment of peak inspiratory flow in patients with chronic obstructive pulmonary disease: a multicentre, observational, prospective, real-life study

Introduction Patients with chronic obstructive pulmonary disease (COPD) use dry powder inhalers (DPIs) for disease management. DPI effectiveness relies on the patient’s peak inspiratory flow (PIF), which may not always be optimal. We conducted an observational multicentre, prospective, real-life cohort study to determine the prevalence of suboptimal PIF in patients with COPD. Methods 415 participants (11%, n=47women, mean age=70±8.7 years, mean forced expiratory volume in 1 s (predicted %)=48.1%) recruited from 17 international centres had baseline PIF recorded with an In-Check Dial device at three resistance levels: (1) low, (2) high and (3) the participant’s maintenance device. We also recorded PIF from participants as they would do at home to verify their proper inhalation technique. Participants underwent spirometry and completed questionnaires (COPD Assessment Test (CAT), Test of Adherence to Inhalers (TAI)-12). Results Of the 415 participants, 18% of DPI users (n=75) exhibited suboptimal values of PIF (as typical PIF