A challenge in a large-scale study is the ability to identify a valid AD phenotype efficiently. Because alcohol dependence is a complex trait and comparatively small samples of alcohol dependent subjects have been studied to date using GWAS, it is not surprising that few specific variants have been implicated consistently (Hart and Kranzler, 2015). Electronic health record (EHR) data are a potentially important source of phenotypic information. As MVP investigators, we sought to develop an EHR-based approach that went beyond administrative diagnostic codes for alcohol use disorder, which can be insensitive (McGinnis et al., 2010, McGinnis et al., 2013). Alcohol screening questionnaires, which are increasingly used in routine clinical care, could provide an alternative. One such instrument is the Alcohol Use Disorders Identification Test (Saunders et al., 1993) or AUDIT, a 10-question, self-report screening test for harmful alcohol use. The AUDIT-C, which includes only the first three (quantity and frequency) questions of the AUDIT, is a practical, valid, primary care screening test for heavy drinking and/or active alcohol abuse or dependence. Developed using questionnaire and telephone interview data from 243
