Prebronchodilator FEV1% predicted			Postbronchodilator FEV1% predicted
	OR (95% CI)	P value	AIC	OR (95% CI)	P value	AIC
Chronic bronchitis	0.98 (0.98 to 0.99)	<0.001	8833	0.98 (0.98 to 0.99)	<0.001	8833