Table 2.

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

Study	Intervention	Controls	Odds ratio	95% CI	z	P
T J Chang 2000	16/157	13/248	2.051	0.958–4.391
Balazs Gyorffy 2002	33/107	23/103	1.551	0.835–2.881
Vaselin Scrabic 2003	66/134	51/132	1.542	0.947–2.509
J J San Pedro 2005	15/71	28/88	0.574	0.278–1.185
Diego Garcia 2007	54/216	43/203	1.240	0.786–1.957
C Panierakis 2009	23/100	37/96	0.476	0.256–0.886
Greear R M 2013	15/55	12/50	1.187	0.493–2.861
Chung Cheon 2015	5/81	9/113	0.760	0.245–2.359
Total (fixed effects)	227/921	216/1033	1.113	0.893–1.388	0.954	0.340
Total (random effects)	227/921	216/1033	1.081	0.755–1.547	0.425	0.671
Q	16.3471
DF	7
Significance level	P = 0.0221
I2 (inconsistency)	57.18%
95% CI for I2	5.93–80.51

Bias indicators: Begg–Mazumdar: Kendall’s Tau = −0.142857 P = 0.5484 (low power); Egger: bias = −1.369742 (95% CI = −6.646958 to 3.907474) P = 0.5488; Harbord–Egger: bias = −1.179831 (92.5% CI = −5.949539 to 3.589877) P = 0.6138.

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