UKB is a population-based sample comprising 502 629 individuals resident in the United Kingdom between the age of 40 and 69 years.23 During the recruitment period from 2006 to 2010, individuals were recruited from 22 centres across the United Kingdom to reflect a broad socioeconomic demographic and mixture of urban and rural residents. During a self-completed touchscreen interview taken at baseline appointment, participants were asked about their current drinking status (never, previous, current, prefer not to say) and were asked to report their average weekly and monthly alcohol consumption of a range of drink types (red wine, white wine, champagne, spirits, beer/cider, fortified wine). These questions were accompanied by pictures providing an example of a single measure of each drink type. From these measures we derived an average intake of alcohol consumption in units per week. We excluded all former drinkers from the analysis and this left 112 117 individuals with data on both alcohol consumption and genome-wide genotype data. We also repeated our analyses with never drinkers excluded (N=108 309) and found the GWAS results to be consistent with the GWAS of the full sample.
