Table 11.

P values testing Hardy–Weinberg proportion and test for heterogeneity of studies included in the meta-analysis for TaqITT polymorphism respectively.

Study	Intervention	Controls	Odds ratio	95% CI	z	P
Chang 2000	142/157	233/248	0.609	0.289–1.284
Balazs Gyorffy 2002	44/107	42/103	1.014	0.585–1.759
Vaselin Scrabic 2003	54/134	48/132	1.181	0.720–1.938
J J San Pedro 2005	24/71	31/88	0.939	0.486–1.813
Diego Garcia 2007	115/216	121/203	0.772	0.524–1.137
C Panierakis 2009	10/100	34/96	0.203	0.0933–0.440
Greear R M 2013	18/55	26/50	0.449	0.204–0.990
Chung Cheon 2015	66/81	105/113	0.335	0.135–0.834
Total (fixed effects)	473/921	640/1033	0.713	0.580–0.876	−3.213	0.001
Total (random effects)	473/921	640/1033	0.644	0.440–0.942	−2.270	0.023
Q	20.6282
DF	7
Significance level	P = 0.0044
I2 (inconsistency)	66.07%
95% CI for I2	28.03–84.00

Bias indicators: Begg–Mazumdar: Kendall’s Tau = −0.642857 P = 0.0141 (low power); Egger: bias = −3.773452 (95% CI = −8.197852 to 0.650947) P = 0.0819; Harbord–Egger: bias = −3.522136 (92.5% CI = −8.048273 to 1.004) P = 0.1452.

DF, degree of freedom; Q, heterogeneity in meta analysis.