Quantifying the shape of the maximal expiratory flow–volume curve in mild COPD

Abstract Maximal expiratory flow–volume (MEFV) curve evaluation using absolute and percent predicted values of flow and volume are used to diagnose respiratory disease, but the shape of the curve is rarely used. Three mathematical methods were used to quantify shape of MEFV curves in subjects with mild COPD ( n  = 19) and matched healthy controls ( n  = 15). Those with mild COPD had a significantly greater slope-ratio (SR) (1.90 ± 0.24 vs. 1.28 ± 0.32) and Beta-angle (160 ± 6.7 vs. 186 ± 15.0) compared to healthy individuals ( p  p