Using logistic regression, screening classification, gender, age group, education group, and ethnicity were tested for associations with each type of treatment service received, whether the subject reported a current (12-month) alcohol or drug use disorder at the 15-year follow-up; and whether they reported DOL within the 3 months before the 15-year follow-up. The CIDI, which bases diagnoses on the DSM-IV criteria, was used to determine retrospectively which subjects met criteria for a SUD at screening and at the 15-year follow-up.
