Table II.

Combined analysis under all genetic models.

			Heterogeneity
Genetic modela	OR (95% CI)	PZ	PQ	I2 (%)
C vs. G	0.77 (0.43–1.40)	0.40	0.01	63.5
CC vs. GG	0.52 (0.20–1.35)	0.18	0.51	0.0
GC vs. GG	0.73 (0.38–1.40)	0.34	0.01	65.7
CC vs. GG+GC	0.64 (0.24–1.71)	0.37	0.74	0.0
CC+GC vs. GG	0.73 (0.38–1.41)	0.35	0.01	66.2

^aCertain studies had to be excluded in some genetic comparison models for 915G/C, as they contained no individuals carrying these genotypes. For C vs. G, GC vs. GG and CC+GC vs. GG, the study by Suzuki et al (21) was excluded; for CC vs. GG and CC vs. GG+GC, Suzuki et al (21), Zein et al (20) and Wang et al (19) were excluded.

OR, odds ratio; 95% CI, 95% confidence interval; P_Z, P-value of Z test; P_Q, P-value of Cochran’s Q statistic; I², value of I² statistic.