Evaluation of Drug Abuse Treatment

The present study utilizes a repeated measures design to evaluate methadone maintenance (MM) treatment effects. The addiction history of MM clients was examined from the beginning of daily narcotic use to the date of interview and was aggregated into the following three time periods: (1) a relatively long pretreatment baseline, (2) all time periods while in treatment, and (3) all time periods not in treatment after the initial treatment entry. These three time periods reflect treatment statuses before, on, and off treatment, respectively. Multiple measures were taken during each treatment status for a sample of 720 MM clients with heterogeneous background characteristics. A repeated measures analysis of variance was conducted for each measure, treating treatment status as the repeated factor, or within-subject variable, and sex, ethnicity, and treatment duration ratio as three between-subject variables. Overall, compared to pretreatment measures, results showed significant improvement for both postadmission statuses: in treatment and not in treatment. Amount of improvement was affected by sex, ethnicity and treatment duration ratio. Findings suggest that MM treatment is an effective intervention, that retention needs to be improved for chronic heroin addicts, and that consideration must be given to client characteristics in assessing treatment effects.