analyzed as a single cohort while the remaining contributing consortia (ADGC [Alzheimer’s Disease Genetics Consortium], CHARGE [Cohorts for Heart and Aging Research in Genomic Epidemiology], and EADI [European Alzheimer’s Disease Initiative]) reflected meta-analyzed summary statistics obtained from individual cohorts. Thus, a single EffN was calculated for GERAD while EffN was calculated for each of the contributing cohorts for the other consortia prior to summing them all together to produce a single ∑EffNk for ALZ. For all traits, the liability-scale heritability was then calculated using either our proposed approach of inputting ∑EffNk or the field standard approach of using vTotal. For ∑EffNk, the SNP-specific sum of effective sample sizes was used when available. Similarly, when using vTotal, the SNP-specific total sample size was used when this information was available. Bias was calculated here as the proportion of the ∑EffNk estimate captured by vTotal: (15) hl2EstimateforvTotalhl2estimatefor∑EffNk−1
