and involved more than 11,000 patients in 41 programs between 1979 and 1981.
Longitudinal, non-experimental analyses of the cost-effectiveness of substance abuse treatment programs in both the DARP and TOPS studies showed that substance abuse treatment programs (long-term residential, out-patient drug-free, and methadone maintenance) were effective in reducing illicit drug use during and after treatment. The analyses of data collected in these earlier studies focused on relating patient histories of illicit drug use and participation in treatment to their observed illicit drug use and criminal activities in the follow-up period. While the TOPS study obtained more program-level data than DARP, information collected about treatment programs or organizations was limited in focus to the types of services delivered and program environments.
In the early 1980s, federal funding for substance abuse treatment was significantly reduced, while new problems emerged — different patterns of drug use (e.g., crack cocaine use), AIDS, and inadequate resources for treatment, along with changes in the organizational structure of the treatment system — that limited the applicability of previous study findings. The 1981 Omnibus Budget Reconciliation Act not only decreased funding for these programs by 25 percent, but it also converted public monies for substance abuse treatment into state block grants.
In an effort to address some of the more complex questions about substance abuse treatment effectiveness, additional, large-scale studies were subsequently initiated in the mid- to late 1980s: the Outpatient Drug Abuse Treatment Systems (ODATS) study and the Drug Abuse Treatment Outcomes Study (DATOS). ODATS, which is ongoing, surveys unit directors and supervisors in substance abuse treatment programs to obtain extensive organization-level data on the characteristics of substance abuse treatment programs, their environments, and their patients. ODATS has progressed through four waves of data collection from a total of more than 600