[Skip to Navigation]
Comment & Response
October 22/29, 2019

FEV1:FVC Thresholds for Defining Chronic Obstructive Pulmonary Disease—Reply

Author Affiliations
  • 1Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham
  • 2Division of General Medicine, Columbia University Medical Center, New York, New York
JAMA. 2019;322(16):1611-1612. doi:10.1001/jama.2019.13960

In Reply We disagree with Drs Miller and Stanojevic that our results1 were mainly due to clinicians’ use of the fixed ratio of 0.70 for the diagnosis of COPD. Clinicians were blinded to study spirometry, and spirometry is substantially underutilized in clinical care. Furthermore, in the context of substantial debate on optimal spirometric criteria, it is unknown which threshold may have been selected by treating physicians. In a number of cases, it is possible that a clinical diagnosis of chronic bronchitis was made. A diagnostic threshold should have meaningful prognostic utility, and in the absence of a diagnostic biomarker for COPD, unlike troponin for acute myocardial infarction, hard clinical outcomes are a valid surrogate.