per stratum, with probability proportional to the size of the estimated 1996 population of the stratum. At the second stage, housing units and group quarter units (converted to housing unit equivalents) were systematically selected within the PSUs. Non-Hispanic Black and Hispanic housing units were selected at higher rates than other housing units. At the third stage, within each household, one person was selected randomly from a roster of people living in the household. Within group quarters, respondents were selected based upon the position of their name on the list obtained by interviewers. Young adults ages 18–24 were sampled at a rate of 2.25 times that of other members of the household. The household response rate for the NESARC was 89 percent, and the person response rate was 93 percent, yielding an overall response rate of 81 percent, and resulting in a final sample of 43,093. The weighted data were then adjusted to represent the US civilian population based on the 2000 census.
