. Author manuscript; available in PMC: 2008 May 12.

Published in final edited form as: Am J Epidemiol. 2007 Dec 5;167(5):570–578. doi: 10.1093/aje/kwm343

Table 5.

Adjusted ORs for COPD across quintiles of energy adjusted intake of total fiber, stratified by sex, ethnicity, and smoking status ^*

	No. of subjects/cases	Quintiles of energy-adjusted intake of total fiber					p value for trend^†	p value for interaction^‡
	No. of subjects/cases	1(lowest)	2	3	4	5	p value for trend^†	p value for interaction^‡
Sex
Female	6,799/756	1	1.01 (0.77, 1.33)	0.90 (0.68,1.19)	0.84 (0.62,1.13)	0.92 (0.67,1.28)	0.455	0.429
Male	5,098/997	1	1.01 (0.80,1.26)	0.90 (0.71,1.15)	0.83 (0.63,1.07)	0.77 (0.57,1.03)	0.041	0.429
Ethnicity
Black	2,798/307	1	1.00 (0.68,1.47)	1.18 (0.79,1.75)	1.00 (0.63,1.58)	1.32 (0.81,2.15)	0.300	0.003
White	9,099/1,446	1	1.01 (0.84,1.23)	0.85 (0.70,1.05)	0.81 (0.65,1.00)	0.79 (0.62,1.00)	0.016	0.003
Smoking status
Never	5,174/291	1	1.17 (0.76,1.80)	0.97 (0.62,1.50)	1.02 (0.65,1.59)	1.13 (0.70,1.84)	0.772	0.275
Current/past	6,723/1,462	1	0.99 (0.82,1.19)	0.90 (0.73,1.10)	0.79 (0.63,0.98)	0.78 (0.61,0.99)	0.013	0.275

COPD defined by either chronic bronchitis (n=669) or spirometry-defined COPD (n=1,321) or both (n=1,753). Covariates included age, sex, study center, ethnicity, smoking status (current smoker, former smoker with ETS, former smoker without ETS, never smoker with ETS, never smoker without ETS), pack years, BMI, occupation, education, diabetes status, traffic density, total energy intake, glycemic index, micronutrients (carotenoids, vitamins C, D, E, and omega-3 polyunsaturated fatty acids) from both food and supplements, and cured meat.

^†

Tests for linear trends across increasing quintiles of fiber intake used the median values in each quintile.

^‡

Likelihood ratio test for interaction (effect modification) by sex, ethnicity, and smoking status.