Interviews were conducted by professional interviewers from the US Census Bureau. On average, the interviewers had 5 years of experience working on census and other health-related national surveys. Training was standardized under the direction of the National Institute on Alcohol Abuse and Alcoholism Alcohol (NIAAA). All procedures, including informed consent, received full ethical review and approval from the U.S. Census Bureau and U.S. Office of Management and Budget.
