1. Abandoning FEV1/FVC <0.70 to Detect Airway Obstruction
Bas Robberts, MD, Tjard Schermer, PhD 
CHEST 
Volume 139, Issue 5, Pages (May 2011)
DOI: /chest
Copyright © 2011 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Association between FEV1/FVC and age in male symptomatic current and ex-smokers aged ≥ 50 years referred for spirometric testing by their primary care physician (n = 3,473). The horizontal red line indicates the fixed 0.70 FEV1/FVC cutoff point that is currently recommended by all major clinical COPD guidelines; the black diagonal line indicates the lower limit of normal for healthy nonsmoking men. Black circles = true negatives; green circles = true positives (unique subjects considered to have airflow obstruction according to both definitions); red circles = false positives (subjects in whom discordant conclusions regarding the presence of airflow obstruction are drawn, n = 558, 16% of all subjects). (Adapted with permission from Schermer et al.4)
CHEST  , DOI: ( /chest )
Copyright © 2011 The American College of Chest Physicians Terms and Conditions