Lower Limit of Normal Is Better Than 70% or 80%

摘要

Congratulations to Miller and colleagues1 for their excellent contribution in this issue of CHEST (see page 52) that points out some of the flaws in defining abnormal lung function by using fixed thresholds of <70% FEV1/FVC to define airway obstruction and an FEV1 <80% predicted to define abnormalities for spirometry, lung volumes, and diffusing capacity of the lung for carbon monoxide (Dlco). These authors reviewed the pulmonary function tests of > 11,000 consecutive white adult patients seen at medical centers in Birmingham, England; St. Louis, Missouri; and Christchurch, New Zealand. The reference equations and methods used at these sites differed only in minor ways.