TREATMENT RETENTION AND FOLLOW-UP OUTCOMES IN THE DRUG-ABUSE TREATMENT OUTCOME STUDY (DATOS)

Clients in the national Drug Abuse Treatment Outcome Study reported si gnificant overall improvements in drug use and related measures during a 12-month follow-up period. A quasi-experimental design was used to examine the relationship of treatment duration with outcomes in each o f the 3 major modalities represented. Client subsamples with longer re tention in long-term residential programs and in outpatient methadone treatment had significantly better outcomes than those with shorter le ngths of stay (results were inconclusive for outpatient drug-free prog rams because of sample limitations). This study used several methodolo gical enhancements and showed general continuity of findings on retent ion effects from previous national evaluations of treatment effectiven ess. It supports the need for more careful study of treatment process in relation to outcomes.