The primary purpose of these programs is to use a court’s  authority to reduce crime by changing defendants’ substance abuse  behavior. Our  analysis of evaluations reporting recidivism data for 23 programs showed  that lower percentages of drug court program participants than  comparison group members were rearrested or reconvicted. Completion rates, which refer to the number of individuals who  successfully completed a drug court program as a percentage of the total  number admitted, in the programs we reviewed that assessed completion  ranged from 27 to 66 percent. No other program factor, such  as the severity of the sanction that would be invoked if participants failed  to complete the program and the manner in which judges conducted status  hearings, predicted participants’ program completion. A limited number of evaluations in our review discussed the costs and  benefits of adult drug court programs. Four evaluations of seven drug  court programs provided sufficient cost and benefit data to estimate their  net benefits (that is, the benefits minus costs). However, all seven programs  yielded positive net benefits, primarily from reductions in recidivism  affecting both judicial system costs and avoided costs to potential victims. Financial  cost savings for the criminal justice system (taking into account recidivism  reductions) were found in two of the seven programs. These results are consistent with those of past reviews  of drug court evaluations. Appendix I: Objectives, Scope, and Methodology

The 21st Century Department of Justice Appropriations Authorization Act  requires that we assess drug court program effectiveness. Our objectives  were to assess the results of methodologically sound, published empirical  evaluations of adult drug court programs, particularly relating to   (1) recidivism outcomes of participants and other comparable offenders,  (2) substance use relapse of participants and other comparable offenders,  (3) program completion of participants, and (4) costs and benefits of drug  court programs. The quasi-experiments used one of two types of comparison  groups:    historical comparison group—formed from individuals who received  conventional case processing during a period of time shortly before the  drug court program was implemented and   contemporaneous comparison group—formed from defendants (1) who  were eligible for drug court but received conventional case processing  during the same time period as the drug court program participants,   (2) who were from a district within a court’s jurisdiction from which  arrestees were not eligible to participate in the drug court program, or   (3) who had similar charges and were matched on characteristics. Appendix V: Drug Court Programs Are Associated with Recidivism Reductions

In most of the evaluations we reviewed, adult drug court programs led to  statistically significant recidivism reductions during periods of time that  generally corresponded to the length of the drug court program—that is,  within-program. In most of the programs that reported post-program data, recidivism  reductions occurred for some period of time after participants completed  the drug court program. The specific types of substance  abuse treatment provided to participants differ among programs. Appendix VI: Limited and Mixed Evidence on Drug Court Programs’ Impacts on Substance Use Relapse

Evidence about the effectiveness of drug court programs in reducing  participants’ substance use relapse is limited and mixed. Drug test results generally showed significant reductions in use  during participation in the program, while self-reported results generally  showed no significant reductions in use. All Seven Drug Court Programs Reported Positive Net Benefits

Although six of the seven drug court programs were more costly than  conventional case processing, the monetary value of the benefits from  reduced recidivism—to the justice system and potential victims—was  greater than the costs, producing positive net benefits in all seven  programs. 27, no. “A Systematic Review of  Drug Court Effects on Recidivism.” Forthcoming.
Why GAO Did This Study

Drug court programs, which were established in the late 1980s as a local response to increasing numbers of drug-related cases and expanding jail and prison populations, have become popular nationwide in the criminal justice system. These programs are designed to reduce defendants' repeated crime (that is, recidivism), and substance abuse behavior by engaging them in a judicially monitored substance abuse treatment. However, determining whether drug court programs are effective at reducing recidivism and substance use has been challenging because of a large amount of weak empirical evidence. he 21st Century Department of Justice Appropriations Authorization Act requires that GAO assess drug court program effectiveness. To meet this mandate, GAO conducted a systematic review of drug court program research, from which it selected 27 evaluations of 39 adult drug court programs that met its criteria for, among other things, methodological soundness. This report describes the results of that review of published evaluations of adult drug court programs, particularly relating to (1) recidivism outcomes, (2) substance use relapse, (3) program completion, and (4) the costs and benefits of drug court programs. DOJ reviewed a draft of this report and had no comments. Office of National Drug Control Policy reviewed a draft of this report and generally agreed with the findings.

What GAO Found

Most of the adult drug court programs assessed in the evaluations GAO reviewed led to recidivism reductions during periods of time that generally corresponded to the length of the drug court program. GAO's analysis of evaluations reporting these data for 23 programs showed the following: (1) lower percentages of drug court program participants than comparison group members were rearrested or reconvicted; (2) program participants had fewer recidivism events than comparison group members; (3) recidivism reductions occurred for participants who had committed different types of offenses; and (4) there was inconclusive evidence that specific drug court components, such as the behavior of the judge or the amount of treatment received, affected participants' recidivism while in the program. Recidivism reductions also occurred for some period of time after participants completed the drug court program in most of the programs reporting these data. Evidence about the effectiveness of adult drug court programs in reducing participants' substance use relapse is limited to data available from eight drug court programs. Evaluations of these eight drug court programs reported mixed results on substance use relapse. For example, drug test results generally showed significant reductions in use during participation in the program, while self-reported results generally showed no significant reductions in use. Completion rates, which refer to the percentage of individuals who successfully completed a program, in selected adult drug court programs ranged from 27 to 66 percent. Other than participants' compliance with drug court program procedures, no other program factor (such as the severity of the sanction that would be invoked if participants failed to complete the program) consistently predicted participants' program completion. A limited number of evaluations--four evaluations of seven adult drug court programs--provided sufficient cost and benefit data to estimate their net benefits. Although the cost of six of these programs was greater than the costs to provide criminal justice services to the comparison group, all seven programs yielded positive net benefits, primarily from reductions in recidivism affecting judicial system costs and avoided costs to potential victims. Financial cost savings for the criminal justice system (taking into account recidivism reductions) were found in two of the seven programs.