Supplementary Figure 8: QQ plots for tests of heterogeneity between study designs.
QQ plot of p-values for (A) the 1 degree of freedom test of heterogeneity between simple family-based EU cohorts tested using the GEE model (ncase=2,107, ncontrol=12,353) and complex family-based EU cohorts tested using the logistic mixed model (ncase=2,897, ncontrol=5,565); (B) the 1 degree of freedom test of heterogeneity between genotyped family-based EU cohorts (ncase=5,004, ncontrol=17,918) and genotyped unrelated case/control EU cohorts (ncase=4,844, ncontrol=8,873); and (C) the 1 degree of freedom test of heterogeneity between genotyped EU cohorts (ncase=9,848, ncontrol=26,791) and EU cohorts included with summary statistics only (ncase=1,721, ncontrol=8,208). Heterogeneity is tested with respect to a fixed effects model for meta-analysis of p-values with effective sample size-based weights. Little deviation is observed from the expected null distribution, suggesting limited heterogeneity between study designs.
