Potential NESARC respondents were informed in writing about the nature of the survey, the statistical uses of survey data, the voluntary nature of participation, and federal laws protecting confidentiality of identifiable survey information. Respondents who consented to participate after receiving this information were interviewed in person by interviewers from the U.S. Census Bureau, who entered responses directly into laptop computers. The response rate was 81%, and a total of 43 093 respondents were interviewed. The research protocol, including informed-consent procedures, received full ethical review and approval from the U.S. Census Bureau and the U.S. Office of Management and Budget.
