In the present study, no evidence of publication bias was found in either Asian or European populations (P(T) > 0.05) for either allelic or genotypic analyses. However, evidence of publication bias was found when all the populations were combined (Egger's regression P = 0.001 (1-tailed) for the allelic analysis and P = 0.002 (1-tailed) for the recessive model but not significant using Kendall's tau (Begg and Mazumdar rank correlation)(Begg and Mazumdar 1994) with P > 0.05). The Duval and Tweedie's trim and fill analysis showed that for the allelic analysis there might potentially be 10 missing studies, and the adjusted overall effect size was 1.28(1.11, 1.48), which was still significant (it was not significant for the recessive model).
