NSDUH defined seven mutually exclusive groups based on respondents’ self-reported race and ethnicity: non-Hispanic white, non-Hispanic black, non-Hispanic native-American (American Indian/Alaska-native), non-Hispanic native-Hawaiian/Pacific-Islander, non-Hispanic Asian-American, mixed-race (>1 race), and Hispanic. The public-use data did not distinguish between specific racial groups of mixed-race individuals. The US census data estimated that 83% of mixed-race individuals were white in combination with ≥1 other race (black, Asian-American, native-Hawaiian/Pacific-Islander, native-American, or other) (US Census Bureau, 2011). We examined respondents’ age group, sex, and educational level to describe their key demographic and to include them as control variables in the analysis of racial/ethnic differences in CU and CUD due their association with drug use (Hasin and Grant, 2015). Survey year also was included as a covariate.
