Table 1. Characteristics of cohort studies evaluating coffee consumption and colorectal cancer risk included in a meta-analysis.

	Study period	Sex	Coffee intake	RR (95% CI)	Reference category
Colon
Oba et al26	1992–2000	Men	1 cup/month–1 cup/day	1.13 (0.71, 1.81)	<1 cup/month
			>1 cup/day	0.81 (0.46, 1.42)
		Women	1 cup/month–1 cup/day	0.92 (0.59, 1.43)	<1 cup/month
			>1 cup/day	0.43 (0.22, 0.85)
Naganuma et al27	1990–2001	Men	Occasionally	1.20 (0.78, 1.85)	Never
			1–2 cups/day	1.06 (0.66, 1.72)
			>3 cups/day	0.91 (0.49, 1.69)
		Women	Occasionally	1.40 (0.83, 2.36)	Never
			1–2 cups/day	1.05 (0.56, 1.95)
			>3 cups/day	1.16 (0.47, 2.88)
Lee et al28	1990–2002	Men	<1 cup/day	1.12 (0.87, 1.42)	Almost never
			1–2 cups/day	0.94 (0.70, 1.25)
			>3 cups/day	1.15 (0.80, 1.66)
		Women	<1 cup/day	0.87 (0.64, 1.19)	Almost never
			1–2 cups/day	0.94 (0.67, 1.33)
			>3 cups/day	0.60 (0.31, 1.19)
Yamada et al29	1988–2009	Men	1 cup/day	1.06 (0.76, 1.47)	<1 cup/day
			2–3 cups/day	1.26 (0.93, 1.70)
			>4 cups/day	1.79 (1.01, 3.18)
		Women	1 cup/day	1.00 (0.72, 1.37)	<1 cup/day
			2–3 cups/day	0.86 (0.57, 1.30)
			>4 cups/day	2.02 (0.81, 5.03)
Rectum
Naganuma et al27	1990–2001	Men	Occasionally	1.07 (0.61, 1.87)	Never
			1–2 cups/day	0.93 (0.51, 1.71)
			>3 cups/day	0.92 (0.45, 1.90)
		Women	Occasionally	0.84 (0.44, 1.60)	Never
			1–2 cups/day	0.85 (0.42, 1.72)
			>3 cups/day	1.08 (0.42, 2.82)
Lee et al28	1990–2002	Men	<1 cup/day	0.69 (0.48, 0.99)	Almost never
			1–2 cups/day	0.94 (0.64, 1.36)
			>3 cups/day	1.01 (0.61, 1.66)
		Women	<1 cup/day	1.04 (0.67, 1.62)	Almost never
			1–2 cups/day	1.16 (0.72, 1.88)
			>3 cups/day	0.84 (0.36, 1.94)
Yamada et al29	1988–2009	Men	1 cup/day	1.19 (0.79, 1.80)	<1 cup/day
			2–3 cups/day	1.12 (0.75, 1.70)
			>4 cups/day	1.19 (0.48, 2.95)
		Women	1 cup/day	0.88 (0.48, 1.59)	<1 cup/day
			2–3 cups/day	1.55 (0.89, 2.69)

CI, confidence interval; RR, relative risk.