Results from 23andMe were adjusted for variance inflation by multiplying the variance (i.e. square of the standard error) of each genetic effect estimate by the intercept of 1.0598 as calculated by LD score regression20. Meta-analysis with PGC was conducted by inverse-variance fixed effects meta-analysis on overlapping SNPs after adjusting the standard errors of each individual analysis for its own lambda (LD score regression intercept in PGC was 1.0243). Final results from the meta-analysis were further adjusted for the overall LD score regression intercept of 1.0025 (for more details on LD score regression methods see section on LD score regression).
