Association between chronic bronchitis (CB+) and the risk of all-cause death in chronic obstructive pulmonary disease (COPD), additionally stratified according to sex

Model 1Model 2
HR (95% CI)p-valueHR (95% CI)p-value
Subjects n924878
COPD CB+1.45 (1.14–1.84)0.0021.33 (1.04–1.71)0.024
Male COPD CB+1.32 (0.98–1.78)0.0721.22 (0.89–1.65)0.212
Female COPD CB+1.69 (1.14–2.53)0.0101.57 (1.03–2.40)0.036

Model 1: age and sex# adjusted; model 2: adjusted for age, sex# and pack-years of cigarette smoking. HR: hazard ratio. #: unstratified analyses only.