Table 2.

Cross-classification and κ Coefficient of the FFQ and the 24HDR Categories^a of Daily Caffeine, Coffee, Coffee Drinks/Cocoa, Tea, and Soda Intakes (n = 249) in the BioCycle Study, 2005–2007

	Same Category		Adjacent Category		Extreme Category		Weighted κ	95% CI
	No.	%	No.	%	No.	%
Caffeine, mg/day	124	50	99	40	5	2	0.51	0.43, 0.58
Coffee, cups/dayb,c	177	71	63	25	1	0.004	0.74	0.68, 0.80
Coffee drinks/cocoa, cups/dayd	103	41	53	21	34	14	0.17	0.10, 0.24
Tea, cups/day	123	49	75	30	7	3	0.43	0.35, 0.52
Soda, cups/day	132	53	87	35	1	0.004	0.53	0.46, 0.61

Abbreviations: CI, confidence interval; FFQ, food frequency questionnaire; 24HDR, 24-hour dietary recall.

^a Caffeine intake is divided into 4 categories on the basis of quartiles; intake of caffeinated beverages is divided into 4 categories: nonconsumers and tertiles.

^b Coffee is all types but “not lattes or mochas.”

^c 1 cup = 237 mL.

^d Coffee drinks/cocoa includes “latte, cappuccino, mocha, or hot chocolate.”