Research subjects for the original study were 1,204 men and women aged 18 and over admitted to treatment between April 1994 and April 1996. Patients were offered the choice of accepting random assignment to day treatment or to the less intensive outpatient program. Those not agreeing to be randomized (i.e., self-selected into either program) were also followed and included in the study. Participants were recruited at intake by licensed master’s level research associates from the Division of Research (DOR). Interviews at 6 months, 1, 5, 7, 9, and 11 years after treatment intake were administered by telephone from the DOR in Oakland, CA. Breath and urinalysis were used to validate self-report.
