In Table 1, characteristics of the sample at each assessment wave are displayed. (In Supplemental Table 2, data are presented by age at assessment.) Of those eligible for the 8 year follow-up, 73% were interviewed. Female participants comprised a somewhat greater proportion at each successive wave. As expected, use of alcohol, tobacco and cannabis increased across the waves as the sample became older. Ever use of cannabis was more prevalent than ever use of cigarettes, consistent with the latest data from the Monitoring the Future study (Johnston et al, 2016). Overall, the data revealed maintenance of the high risk nature of the sample over time.
