Table 2. Stratification for the test of heterogeneity on IL-8 -251 AA vs TA based on a codominant model.

	Q-test			OR(95%CI)	P value
	chi-squared	d.f.	p
Overall	35.96	17	0.005	1.17(0.98–1.40)	0.092
Large sample	23.18	9	0.006	1.12 (0.90–1.40)	0.305
Small-and-moderate sample	11.75	7	0.109	1.25 (0.98–1.59)	0.067
High quality	17.88	10	0.057	1.25 (1.03–1.51)	0.023
Low-and-moderate quality	14.28	6	0.027	1.03 (0.71–1.49)	0.892
Publication before or in 2005	17.20	5	0.004	1.23(0.82–1.85)	0.326
Publication after 2005	18.40	11	0.073	1.13 (0.93–1.37)	0.222
Caucasians	0.98	3	0.806	0.93 (0.76–1.13)*	0.453#
Asians	27.54	12	0.006	1.31 (1.04–1.66)	0.024
Non-cardia type	4.56	7	0.714	0.85 (0.70–1.04)*	0.122#
Cardia type	4.77	4	0.311	1.22 (0.97–1.55)*	0.092#
Intestinal type	4.96	6	0.549	1.08 (0.83–1.40)*	0.583#
Diffuse type	6.42	3	0.093	0.89 (0.52–1.53)	0.672
Hp positive	14.11	3	0.003	1.22 (0.62–2.43)	0.564
Hp negative	2.43	2	0.297	0.88 (0.57–1.38)	0.589
PCR-RFLP genotyping	12.46	6	0.052	1.07 (0.82–1.41)	0.607
Other genotyping	23.23	10	0.010	1.25 (0.97–1.61)	0.084

*: M-H ORs (95% CI), otherwise D+L ORs (95% CI).

^#: P values of M-H estimates, otherwise P values of D+L estimates.