Comparison between an Alternative and the Classic Definition of Chronic Bronchitis in COPDGene

摘要

Rationale: Previous studies on chronic bronchitis (CB) have used varying definitions.Objectives: We sought to compare an alternative CB definition, using the St. George's Respiratory Questionnaire (SGRQ), a commonly used assessment tool, with the classic definition and to investigate if it had independent or additive value.Methods: We analyzed data from 4,513 subjects from Global Initiative for Chronic Obstructive Lung Disease groups 1 to 4 in the COPDGene cohort. We compared the classic definition of CB with the SGRQ definition, defined by their answers to the questions about both cough and phlegm. We compared the Classic CB+ versus CB- groups, and the SGRQ CB+ and CB-groups. We also analyzed the cohort split into four groups: Classic CB+/SGRQ CB+, Classic CB+/SGRQ CB-, Classic CB-/SGRQ CB+, Classic CB-/SGRQ CB-.