The Effectiveness of Incarceration‐Based Drug Treatment on Criminal Behavior: A Systematic Review

This updated Campbell systematic review examines the effectiveness incarceration‐based drug treatment interventions in reducing postrelease recidivism and drug use. The review summarises findings from 74 studies, 65 of which were conducted in the United States, four in Canada, three in Australia, one in Taiwan and one in the United Kingdom. The main evidence presented in this review suggests that the effectiveness of treatment programs varies by the type of treatment. These findings most strongly support the effectiveness of therapeutic communities, as these programs produced relatively consistent reductions in recidivism and drug use. Boot camps have no effect on either outcome. These conclusions should be read with caution given the limited number of such evaluations and general methodological weakness. Therapeutic community programs were the only programs to consistently show modest reductions in recidivism and drug relapse however, there is evidence of publication bias that could have over‐estimated its effectiveness. Given all these shortcomings, further evidence regarding the effectiveness of this type of intervention is needed. Structured Abstract BACKGROUND Many, if not most, incarcerated offenders have substance abuse problems. Without effective treatment, these substance‐abusing offenders are likely to persist in non‐drug offending. The period of incarceration offers an opportunity to intervene in the cycle of drug abuse and crime. Although many types of incarceration‐based drug treatment programs are available (e.g., therapeutic communities and group counseling), the effectiveness of these programs is unclear. OBJECTIVES The objective of this research synthesis is to systematically review quasi‐experimental and experimental (RCT) evaluations of the effectiveness of incarceration‐based drug treatment programs in reducing post‐release recidivism and drug relapse. A secondary objective of this synthesis is to examine variation in effectiveness by programmatic, sample, and methodological features. In this update of the original 2006 review (see Mitchell, Wilson, and MacKenzie, 2006), studies made available since the original review were included in an effort to keep current with emerging research. SEARCH STRATEGY We searched bibliographic databases, hand searched select journals, and reviewed websites of several research organizations involved in drug treatment research to identify potentially eligible studies. SEARCH CRITERIA Eligible studies needed to assess the effectiveness of incarceration‐based (e.g., jail, prison) drug treatment programs, use experimental or quasi‐experimental comparison group research designs, measured a post‐release recidivism or drug use outcome, and be conducted between 1980 and 2011, inclusive. DATA COLLECTION AND ANALYSIS From each evaluation, we coded an effect size that quantified each program's effect on various measures of recidivism and/or drug relapse. We also coded features of the program, research methodology, and sample. We analyzed effect sizes using the random‐effects inverse‐variance weight method of meta‐analysis. MAIN RESULTS Seventy‐four evaluations met our eligibility criteria. The overall average effect of these programs was approximately a 15 to 17% reduction in recidivism and drug relapse. The effectiveness of such programs, however, varied by program type. Therapeutic communities had relatively consistent but modest reductions in recidivism and drug relapse. Counseling and narcotic maintenance programs had mixed effects. Specifically, counseling programs on average reduced recidivism but not drug relapse, narcotic maintenance programs had sizeable reductions in drug relapse but not recidivism, and boot camps had negligible effects on both recidivism and drug relapse. CONCLUSIONS This synthesis of evaluations of incarceration‐based drug treatment programs found that such programs are modestly effective in reducing recidivism. These findings most strongly support the effectiveness of therapeutic communities, as these programs produced relatively consistent reductions in recidivism and drug use. Both counseling and incarceration‐based narcotic maintenance programs had mixed effects. Counseling programs were associated with reductions in recidivism but not drug use; whereas, incarceration‐based narcotic maintenance programs were associated with reductions in drug use but not recidivism. Note that our findings regarding the effectiveness of incarceration‐based narcotic maintenance programs differ from a larger review of community‐based narcotic maintenance programs (see Egli, Pina, Christensen, Aebi, and Killias, 2009). Finally, boot camp programs for drug offenders had negligible effects on both recidivism and drug use. Plain Language Summary This research synthesized results from 74 evaluations of incarceration‐based drug treatment programs using meta‐analysis. Incarceration‐based drug treatment programs fell into four distinct types: therapeutic communities (TCs), group counseling, boot camps specifically for drug offenders, and narcotic maintenance programs. We examined the effectiveness of each of these types of programs in reducing post‐release offending and drug use, and we also examined whether differences in research findings can be explained by variations in methodology, sample, or program features. Our results consistently found support for the effectiveness of TC programs on both outcome measures, and this finding was robust to variations in method, sample, and program features. We also found support for the effectiveness of group counseling programs in reducing offending, but these programs' effects on drug use were negligible. The effect of narcotic maintenance programs was also mixed with reductions in drug use but not offending. Boot camps had no substantive effect on either outcome measure.