. 2017 Aug 10;50(2):1602470. doi: 10.1183/13993003.02470-2016

TABLE 3.

Association between chronic bronchitis (CB⁺) and the frequent exacerbator phenotype

	Model 1		Model 2
	OR (95% CI)	p-value	OR (95% CI)	p-value
Subjects n	924		878
COPD CB⁺	4.13 (2.82–6.04)	<0.001	3.96 (2.67–5.88)	<0.001
Male COPD CB⁺	3.21 (1.90–5.42)	<0.001	3.11 (1.82–5.31)	<0.001
Female COPD CB⁺	5.16 (2.94–9.05)	<0.001	5.10 (2.83–9.20)	<0.001

Model 1: age and sex^# adjusted; model 2: adjusted for age, sex^# and pack-years of cigarette smoking. COPD: chronic obstructive pulmonary disease. ^#: unstratified analyses only.