The classic fail-safe analysis showed that for the allelic analysis at least 8,512 assumed non-significant studies could bring the overall P(Z) value to > 0.05 for all the studies of AD and alcohol abuse (6,606 for the Asian studies and 62 for the European studies); for the dominant model at least 2,839 assumed non-significant studies could bring the P value to > 0.05 (2,466 for the Asian studies); and for the recessive model it needed at least 5,882 assumed non-significant studies (4,337 for the Asian studies and 64 for the European studies). The results further supported the strong associations detected in this meta-analysis. The funnel plots are shown for the allelic and genotypic analyses of all the studies of AD and alcohol abuse in Figures S3-S5 in Supplement 1. Figure S3 in Supplement 1 indicates the increase of effect size from the observed to adjusted values.
