The Ratio of FEV1 to FVC as a Basis for Establishing Chronic Obstructive Pulmonary Disease

摘要

Rationale: The lambda-mu-sigma (LMS) method is a novel approach that defines the lower limit of normal (LLN) for the ratio of FEV1/FVC as the fifth percentile of the distribution of Z scores. The clinical validity of this threshold as a basis for establishing chronic obstructive pulmonary disease is unknown.