Consistent with our previous work (14), a Heaviness of Drinking [HOD] factor score was derived, using four items: lifetime Max Drinks, and 3 heaviest period measures of frequency of heavy drinking, frequency of drinking to intoxication, and log-transformed average weekly consumption (derived as the product of frequency of use and drinks per drinking day measures). MaxDrinks was log-transformed and, for males only, winsorized in the left tail at 3 standard deviations below the mean, based on mean and standard deviation for the BIGSIB series. For the alcohol use disorder factor score, we included both DSM-IV dependence and DSM-IV abuse items (excluding recurrent legal problems) (AUD-FS), consistent with the perfect genetic correlation between Abuse and Dependence previously reported (14), and the anticipated operationalization of alcohol dependence in DSM-V. For comparison, an alcohol dependence factor (AD-FS) limited to dependence items was also estimated. Factor analyses were conducted separately for the OZALC-NAG and Cohorts 1 and 2 datasets; for the former, factor scoring coeffiecients were generated using the BIGSIB sample, by gender, and then applied to the combined OZALC-NAG data-set. Factor loadings were
