Evaluation of critical inhalation technique errors in patients with COPD on Dry Powder Inhaler maintenance therapy based on their association with health status: findings from the PIFotal study.

Introduction: Inhalation technique errors are detrimental to effective treatment in patients with COPD as they might lead to failure to deliver (part) of the medication dose into the lungs. Based on their association with health status and exacerbations, we aimed to determine which Dry Powder Inhaler (DPI)-specific inhalation technique errors can be considered critical in patients with COPD.

Methods: The PIFotal COPD study is a cross-sectional multi-country observational real-world study including COPD patients using a DPI for maintenance therapy (n=1,434, 50.1% female, mean±SD: 69.2±9.3 yrs). Inhalation technique was recorded and evaluated based on standardized checklists, grouping errors into 10 distinct categories. Health status was assessed with the Clinical COPD Questionnaire (CCQ) and COPD Assessment Test (CAT) and 12-month exacerbation frequency was counted. Critical errors were identified through their association with health status, estimated with multilevel models adjusted for identified confounders. Results:Of all observed errors, errors ‘Breathe in’ (CCQ ß 0.16, 95% confidence interval [CI] [0.05,0.27]), ‘Hold breath’ (CCQ ß 0.14, 95%CI [0.01,0.28]), and ‘Breathe out calmly after inhalation’ (CCQ ß 0.27, 95%CI [0.02,0.52]) were associated with worse CCQ outcomes. Similar results were found for the CAT scores (Figure 1). Errors ‘Preparation’ (rate ratio [RR] 2.83, 95%CI [1.30,6.16]), ‘Hold inhaler in correct position during inhalation’ (RR 1.94, 95%CI [1.05,3.55]), ‘Breathe in’ (RR 1.85, 95%CI [>1.00,3.42]) were associated with more severe exacerbations (Figure 2). 81.3% of patients with COPD made ≥1 critical error while using a DPI. Discussion:This study demonstrates that generic inhalation errors associated with the breathing maneuvers are extremely common and associated with clinically relevant indicators of disease control; while other device-specific errors, such as ‘Preparation’ and ‘Hold inhaler in correct position during inhalation’, also require targeting. Prospective studies should establish the impact of addressing these critical inhalation technique errors on outcomes. *ß= average difference in CCQ-score between Yes’ and ‘No’ error.Figure 1.For continuous outcomes (CCQ / CAT) linear multilevel models were used, reporting the average difference in the absolute score (b) between the dichotomous predictors (‘Yes’, ‘No’ inhalation technique error).Figure 2.For the number of severe exacerbations in the last 12 months multilevel negative binomial regression models were used, reporting Rate Ratios between the dichotomous predictors (‘Yes’, ‘No’ inhalation technique error) Research Idea Abstract Service Development & Evaluation Abstract Declaration of Interest The study sponsor is the General Practitioners Research Institute; data collection and analysis were performed by General Practitioners Research Institute. Boehringer Ingelheim is the funding and scientific partner. References and Clinical Trial Registry Information NCT04532853