Coffee drinking and pancreatic cancer risk: A meta-analysis of cohort studies

Table 1 Summary characteristics of studies included in the meta-analysis

Study	Country	Follow-up period	Study subjects	No. of cases	Coffee consumption	Relative risk (95% CI)	Adjustments
Snowdon et al[12]	United States	1960-1980	23 912	71	< 1 cup/d	1.00 (reference)	Age, sex
			Aged ≥ 30 yr		1 cup/d	1.7 (0.9-3.3)
1984					≥ 2 cups/d	0.8 (0.4-1.6)
Jacobsen et al[13]	Norway	1967-1978	16 555	63	≤ 2 cups/d	1.00 (reference)	Sex, age and residence (men for cigarette smoking)
			13 664 male		3-4 cups/d	1.22 (0.66-2.35)
1986			2891 female		5-6 cups/d	0.53 (0.21-1.26)
					≥ 7 cups/d	0.62 (0.18-1.75)
Nomura et al[14]	Japan	1965-1983	7355 male	21	0 cup/d	1.00 (reference)	Age, years of smoking, number of cigarettes smoked per day, smoking status at exam, and past smoking status
					1-2 cups/d	0.83 (0.16-5.34)
1986					3-4 cups/d	1.39 (0.32-8.31)
					≥ 5 cups/d	1.27 (0.27-7.84)
Hiatt et al[15]	United States	1978-1984	122 894	49	< 1 cup/d	0.4 (0.1-4.3)	Age, sex, ethnic origin, blood glucose levels, consumption of alcohol, tea
1988					1-3 cups/d	1.2 (0.3-4.4)
					> 4 cups/d	0.8 (0.2-4.6)
Zheng et al[16]	United States	1966-1986	17 633 male	57	< 3 cups/d	1.00 (reference)	Age, smoking index, alcohol index
			Aged ≥ 35 yr		3-4 cups/d	0.6 (0.3-1.2)
1993					5-6 cups/d	0.7 (0.4-1.6)
					≥ 7 cups/d	0.9 (0.3-2.4)
Shibata et al[17]	United States	1981-1990	13 979	63	< 1 cup/d	1.00 (reference)	Sex, age and cigarette smoking
					1 cup/d	1.82 (0.75-4.43)
1994					2-3 cups/d	1.67 (0.74-3.77)
					≥ 4 cups/d	0.88 (0.28-2.80)
Stensvold et al[18]	Norway	1977-1990	42 973	41	≤ 2 cups/d	1.00 (reference)	Age, cigarette smoking, county of residence
			21 735 male	26 M	3-4 cups/d	2.76 (0.63-25.21)
1994			21 238 female	15 F	5-6 cups/d	3.09 (0.72-27.87)
			Aged 35-54 yr		≥ 7 cups/d	2.71 (0.59-25.15)
Zheng et al[19]	United States	1986-1993	35 369 female	66	Never/monthly	1.00 (reference)	Age, education, smoking status, pack-years of smoking, physical activity, all fruit and vegetable intake, total energy intake, waist/hip ratio, family history of cancer, prior history of blood transfusion
			Aged 55-69 yr		Weekly-3 cups/d	1.82 (0.87-3.82)
1996					≥ 4 cups/d	2.15 (1.01-4.07)
Michaud et al[20]	United	1986-1998	136 593	288	None	1.00 (reference)	Age in 5-yr categories, pack-years of smoking, bidy mass index, history of diabetes mellitus, history of cholecystectomy, energy intake, and period
	States	1980-1996	47 794 male	130 M	< 1 cup/d	0.94 (0.65-1.36)
2001			Aged 40-75 yr	158 F	1 cup/d	0.60 (0.38-0.94)
			88 799 female		2-3 cups/d	0.88 (0.65-1.21)
			Aged 30-55 yr		> 3 cups/d	0.62 (0.27-1.43)
Isaksson et al[21]	Sweden	1961-1997	21 884	131	0-2 cups/d	1.00 (reference)	Sex, age, cigarette smoking
			9680 male		3-6 cups/d	0.91 (0.60-1.38)
2002			12 204 female		≥ 7 cups/d	0.39 (0.17-0.89)
			Aged 36-75 yr
Lin et al[22]	Japan	1988-1997	99 527	225	Nondrinkers		Age, cigarette smoking in pack-years
2002			44 646 male		1-2 cups/mo
			54 881 female		1-4 cups/wk
			Aged 40-79 yr		1 cup/d
					2-3 cups/d
					≥ 4 cups/d
Stolzenberg-Solomon et al[23]	Finland	1985-1997	27 111 male	163	≤ 321.4 g/d	1.00 (reference)	Age, years of smoking
			Aged 50-69 yr		> 321.4- ≤ 450.0 g/d	1.48 (0.89-2.46)
					> 450.0- ≤ 624.9 g/d	1.12 (0.61-2.03)
2002					> 624.9- ≤ 878.6 g/d	1.72 (1.01-2.86)
					> 878.6 g/d	0.95 (0.54-1.68)
Khan et al[24]	Japan	1984-2002	3158	25	≤ several times/mo	1.00 (reference)	Age, sex, health education, health examination, health status, moking
2004			1524 male	12 M	≥ several times/wk	0.38 (0.01-1.05)
			1634 female	13 F
			Aged ≥ 40 yr
Luo et al[25]	Japan	1990-2003	102 137	233	Rarely	1.00 (reference)	Body mass index, frequency of sports, smoking status, alcohol intake, history of diabetes, history of cholelithiasis, study area, age and tea consumption
2007			48 783 male	135 M	1-2 cups/wk	1.0 (0.7-1.4)
			53 354 female	98 F	3-4 cups/wk	1.1 (0.7-1.7)
			Aged 40-69 yr		1-2 cups/d	0.9 (0.6-1.3)
					≥ 3 cups/d	0.8 (0.4-1.3)