Sex as an effect modifier in the association between alcohol intake and gastric cancer risk

Table 1 Summary of previous systematic reviews for evaluating the association between alcohol intake and gastric cancer risk

Ref.	Searching	Selected studies (Cohort)	Group	Summary relative risk (95% confidence interval)	I2 (%)
Han et al[7], 2017	Dec-16	23	Both, HLL	1.17 (1.00-1.34)	79.6
		7	Men, HLL	1.18 (1.06-1.30)	0
		1	Women, HLL	1.13 (0.79-2.25)	0
Wang et al[9], 2017	Dec-16	17	Both, HLL	1.19 (1.06-1.34)	37.6
		34	Men, HLL	1.21 (1.06-1.37)	68.2
		12	Women, HLL	1.18 (0.95-1.47)	26.2
He et al[8], 2017	Apr-17	22	Both, HLL	1.03 (0.99-1.08)	21.9
			Men, heavy	1.13 (1.06-1.22)	28.1
			Women, heavy	1.33 (0.79-2.24)	2.4

HLL: Highest versus lowest level.

Table 2 Subgroup analysis by potential confounders¹

		Men	Women	Both
All		1.18 (1.06-1.32) [13]	1.07 (0.95-1.19) [7]	1.13 (1.04-1.23) [27]
Region
	Asia	1.22 (1.09-1.36) [8]	1.09 (0.91-1.29) [3]	1.43 (1.02-1.28) [13]
	Non-Asia	1.12 (0.83-1.50) [5]	1.07 (0.83-1.38) [4]	1.11 (0.99-1.24) [14]
Level of adjustment of smoking status
	Low	1.14 (0.91-1.41) [7]	1.07 (0.95-1.20) [5]	1.16 (1.06-1.27) [10]
	High	1.19 (1.08-1.31) [6]	1.09 (0.84-1.43) [2]	1.12 (0.98-1.27) [17]
Adjustment of body mass index
	No	1.05 (0.83-1.34) [5]	1.48 (0.93-2.36) [2]	1.12 (0.92-1.36) [8]
	Yes	1.22 (1.08-1.37) [8]	1.05 (0.96-1.17) [5]	1.13 (1.03-1.24) [19]
Year of publication
	Approximately 2005	1.08 (0.88-1.33) [4]	[0]	1.08 (0.89-1.33) [5]
	2006-2010	1.07 (0.81-1.41) [3]	1.48 (0.93-2.36) [2]	1.14 (0.98-1.32) [8]
	2011-	1.26 (1.02-1.56) [6]	1.05 (0.95-1.17) [5]	1.14 (1.00-1.29) [14]
Site
	Cardia	1.07 (0.79-1.44) [1]	1.30 (0.43-3.90) [1]	1.05 (0.81-1.35) [3]
	Non-cardia	0.75 (0.53-1.06) [1]	0.66 (0.24-1.82) [1]	0.84 (0.65-1.08) [3]

¹Summary relative risk (95% confidence interval) [number of cohorts].