Development of a Scoring System to Predict Suboptimal Peak Inspiratory Flow in Patients With Chronic Obstructive Pulmonary Disease.

Background: Peak inspiratory flow rate (PIFR) is a critical indicator for the successful use of dry powder inhalers (DPIs). However, resource constraints often limit the practicality of measuring PIFR prior to DPI prescription.

Methods: A cross-sectional observational study was conducted across seven hospitals in Korea, including patients with chronic obstructive pulmonary disease (COPD). To develop a scoring system to predict suboptimal PIFR without direct measurement, variables were selected through a literature review and logistic regression model, considering practicality in clinical settings.

Results: The study involved 436 patients and was divided into training and test datasets with a 7:3 ratio. Age (≥ 80 years), weight (≤ 60 kg), modified Medical Research Council score (≥ 2), and post-bronchodilator forced vital capacity (≤ 80%pred) were selected to develop the scoring system. The developed scoring system, ranging from 0 to 4 points with a 2-points threshold for predicting suboptimal PIFR, demonstrated acceptable predictive ability for suboptimal PIFR in training (area under the receiver operating characteristic [AUROC], 0.724; 95% confidence interval [CI], 0.660-0.789) and test datasets (AUROC, 0.686; 95% CI, 0.591-0.781).

Conclusion: Our developed scoring system demonstrated an acceptable predictive ability for suboptimal PIFR in COPD patients, utilizing variables that are easily applicable in clinical practice.