The credibility estimates follow from applying Bayes’ Rule to calculate either the probability that the SNP is non-null (an event denoted C) given only the first-stage estimate, P(C|β̂1), or the probability that the SNP is non-null conditional on the results of both the first-stage GWAS and the quasi-replication analysis, P(C|β̂1, β̂2). Credibility estimates for our lead SNPs are in Supplementary Table 14.