Table 3.

Subgroup analysis of whole grains intake and risk of gastric cancer

Subgroups	No. of studies	No. of Participants (Cases)	RR (95% CI)	P	Heterogeneity Test
					Chi-Square	I2	phet
All studies	11	1,021,955(8274)	0.64(0.53,0.79)	< 0.001	50.42	78.2%	< 0.001
Study design
Cohort	2	1,004,696(1518)	0.89(0.78,1.01)	0.070	3.43	41.7%	0.180
Case-control	9	17,259(6756)	0.55(0.41,0.74)	< 0.001	41.59	80.8%	< 0.001
Geographic locations
Europe	8	16,985(6619)	0.64(0.53,0.79)	< 0.001	50.42	78.2%	< 0.001
America	3	1,004,970(1655)	0.70(0.50,1.00)	0.051	9.92	69.8%	0.019
Sample size
≥ 500	10	1,021,681(8137)	0.67(0.54,0.82)	< 0.001	45.51	78.0%	< 0.001
< 500	1	274(137)	0.42(0.24,0.74)	0.003	N/A	N/A	N/A
Adjustment for energy
Yes	1	34,651(169)	0.61(0.34,0.81)	0.026	N/A	N/A	N/A
No	10	987,204(8105)	0.65(0.52,0.80)	< 0.001	49.03	79.6%	< 0.001

Abbreviations:N/A Not applicable