The measure for lifetime maximum number of alcoholic drinks consumed in 24 hour period (maxdrinks) in both the COGA and SAGE datasets was derived from the SSAGA interview (Bucholz et al. 1994). The specific question asked to assess maxdrinks was “What is the largest number of drinks you have ever had in a 24-hour period”? A standard drink of alcohol was defined as a 4 oz. glass of wine, a 12 oz. bottle of beer, or a 1.5 oz. shot glass of 80 proof liquor. The average maxdrinks in the COGA sample and the SAGE samples were similar, with average maxdrinks=25 and maxdrinks=13 in men and women, respectively (Table 1). Phenotypic distributions for both the COGA and SAGE datasets are presented in Supplementary figure 1. Extreme values of maxdrinks (greater than 100) were set at 100. Individuals who did not consume alcohol were classified as unknown and were removed from subsequent analyses. Prior to association analysis, maxdrinks in both datasets were natural log-transformed to acquire a normal distribution (Supplementary figure 1).
