Simpson, D. D., & Flynn, P. M. (2008).   Drug Abuse Treatment Outcome Studies (DATOS): A national evaluation of treatment effectiveness.   In G. Fisher & N. Roget, (Eds.), Encyclopedia of Substance Abuse Prevention, Treatment, and Recovery (pp. 303-307). Thousand Oaks, CA: Sage Publishing.

Abstract:   The DATOS findings illustrate consistent behavioral and psychological improvements for adults and adolescents during residential and outpatient treatments and following discharge across the domains of alcohol and drug use, criminality, social performance, and psychological functioning.  Improvements during treatment and first year after discharge also were largely sustained in the 5-year follow-up results.  Poorer outcomes were associated with lack of engagement in treatment and inadequate retention, especially for clients reporting more serious drug use histories and related problems at admission.  More intensive and sustained services are therefore indicated for drug users with greater needs, and this type of systematic adaptation of therapeutic care to client needs can optimize cost effectiveness of treatment.  However, there were program variations in client engagement and retention that reflect variations in quality of services in practice.  Thus, organizational-level factors that influence treatment quality and efforts to adopt and sustain innovations deserve special attention in future studies of treatment effectiveness.