Meta-analysis combining results from all four samples was done using METAL (http://www.sph.umich.edu/csg/abecasis/metal/) by calculating a Z-statistic that was a weighted average of sample-level statistics, where the weights were proportional to the square root of the number of individuals examined in each sample, and selected so that the squared weights summed to 1. The weight for QIMR reflected only independent individuals. The direction of effect in each study was taken into account in calculating the average. There were 1 252 222 SNPs common to all four data cohorts and scales. The number of individuals analyzed varied by phenotype: HA: 11 597, NS: 11 612, RD: 11 590, P: 11 610.
