quantity and frequency of use among users may differ in important ways from trajectories of any use. For example, previous research has demonstrated that Black young adults have different drinking patterns compared with Whites, including different beverage preferences and premise utilization patterns (Zapolski et al., 2014). Examination of such variation in quantity and frequency is critical, as adverse physical health outcomes secondary to substance use, both in young adulthood and through the lifecourse, are only exhibited at high and chronic levels of consumption (Connor, 2006). Further, existing studies in these data have not controlled for important socio-economic differences across groups; a full accounting is critical in inferring the extent to which racial/ethnic differences persist over and above socio-economic circumstances.
