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 |