The second quantity measure inquired directly about the number of joints usually smoked in a single day during the past 12 months. The quantity-frequency measure derived from these two variables and assessed in this study was smoking at least one joint per week, on average, in the last 12 months. All respondents who met this criterion were coded 1 or positive for this criterion, with the remaining respondents coded 2 or negative for this cannabis use criterion. Similar to all general population surveys, the distribution of cannabis use was relatively restricted, precluding the examination and comparison of a range of cannabis use measures differing in both frequency and quantity. For the purposes of this study, all statistical analyses were conducted on all respondents who had used cannabis during the year preceding the interview.
