The NLAES featured a complex multistage design (Massey et al. 1989). Primary sampling units (PSU’s)1 were stratified according to sociodemographic criteria and were selected with probability proportional to size. Approximately 2,000 PSU’s were in the 1992 NLAES sample, 52 of which were self-representing—that is, selected with certainty. Within PSU’s, geographically defined secondary sampling units, referred to as segments, were selected systematically for each sample. Oversampling of the black population was accomplished at this stage of sample selection. The decision to oversample the black population was based on the higher observed rates of alcohol-related disease (i.e., liver cirrhosis) in this group.
