Hubbard, R. L., Craddock, S. G., Flynn, P. M., Anderson, J., & Etheridge, R. M. (1997). Overview of 1-year follow-up outcomes in the Drug Abuse Treatment Outcome Study (DATOS). Psychology of Addictive Behaviors, 11(4), 261-278.

Abstract:  The Drug Abuse Treatment Outcome Study (DATOS) collected 1-year follow-up outcomes for 2,966 clients in outpatient methadone (OMT), long-term residential (LTR), outpatient drug-free (ODF), and short-term inpatient (STI) programs in 1991-1993. LTR, STI, and ODF clients reported 50% less weekly or daily cocaine use in the follow-up year than in the preadmission year. Reductions were greater (p < .01) for clients treated for 3 months or more. Clients still in OMT reported less weekly or daily heroin use than clients who left OMT. Multivariate analysis confirmed that 6 months or more in ODF and LTR and enrollment in OMT were associated with the reductions. Reductions of 50% in illegal activity and 10% increases in full-time employment for LTR clients were related (p < .01) to treatment stays of 6 months or longer. The results replicated findings from 1979-1981 for heroin use in OMT and illegal activity and employment for LTR but not for illegal activity in OMT and ODF.