Drug Courts' Effects on Criminal Offending for Juveniles and Adults

This Campbell systematic review assesses the effectiveness of drug courts in reducing criminal or drug‐use behaviour recidivism. The review summarises findings from 154 studies, all of which report evidence from adult drug courts, drunk driving (DWI) drug courts, and juvenile courts. All but eight of the studies are of drug courts in the USA. There is a large, significant mean average effect from both adult and DWI drug courts. Overall, recidivism rates were just over one third (38%) for programme participants, compared to half (50%) for comparable non‐participants. This effect endures for at least three years. There is a smaller effect from juvenile drug courts. Program participation reduces recidivism from 50% to 44%. The effects of drug court participation are highly variable. Programs with fewer high‐risk offenders are more effective in reducing reoffending rates. This finding may help explain why juvenile courts are less effective, as they deal with a greater proportion of high‐risk offenders. Variation in intensity of programs is not related to effectiveness. Courts that required more than the standard number of phases or drug tests were no more effective than other courts. The highest quality evidence from three experimental evaluations confirms the impact from adult courts on recidivism, though there was some inconsistency in durability of the effects over time. For DWI drug courts three of the four experimental evaluations produced similar results as the adult drug courts, but one high quality study found negative effects. Abstract BACKGROUND Drug courts are specialized courts in which court actors collaboratively use the legal and moral authority of the court to monitor drug‐involved offenders' abstinence from drug use via frequent drug testing and compliance with individualized drug treatment programs. Drug courts have proliferated across the United States in the past 20 years and been adopted in countries outside the United States. Drug courts also have expanded to non‐traditional populations (juvenile and DWI offenders). OBJECTIVES The objective of this review is to systematically review quasi‐experimental and experimental (RCT) evaluations of the effectiveness of drug courts in reducing recidivism, including drug courts for juvenile and DWI offenders. This systematic review critically assesses drug courts' effects on recidivism in the short‐ and long‐term, the methodological soundness of the existing evidence, and the relationship between drug court features and effectiveness. SEARCH STRATEGY We used a multi‐pronged search strategy to identify eligible studies. We searched bibliographic databases, websites of several research organizations involved in drug court research, and the references of eligible evaluations and prior reviews. SEARCH CRITERIA Evaluations eligible for inclusion in this review were evaluations of drug courts that used an experimental and quasi‐experimental comparison group design. Studies must also have had an outcome that examined criminal or drug‐use behavior (recidivism). DATA COLLECTION AND ANALYSIS From each evaluation, we coded an effect size that quantified each court's effect on various measures of recidivism (general recidivism, drug‐related recidivism, and drug use). We also coded features of the drug court program, research methodology, and sample. We analyzed effect sizes using the random‐effects inverse‐variance weight method of meta‐analysis. MAIN RESULTS One hundred fifty‐four independent evaluations of drug courts met our eligibility criteria; 92 of these assessed adult drug courts, 34 examined juvenile drug courts, and 28 investigated DWI drug courts. If all of the evaluations are considered, the evidence suggests that adult and DWI drug courts reduce general and drug‐related recidivism; in fact, the mean effect size for both adult and DWI drug courts is analogous to a drop in recidivism from 50% for non‐participants to approximately 38% for participants. Moreover, the effects of adult drug courts appear to persist for at least three years. If only the three experimental evaluations of adult drug courts are considered, the evidence still supports the effectiveness of adult drug courts, as all three experimental evaluations find sizeable reductions in recidivism, although there was inconsistency in the durability of the effects over time. Three of the four experimental evaluations of DWI drug courts find sizeable reductions in recidivism; however, one experimental evaluation found a negative effect. Thus, the evidence is suggestive of effectiveness of DWI drug courts but this conclusion is not definitive. For juvenile drug courts we find considerably smaller effects on recidivism. The mean effect size for these courts is analogous to a drop in recidivism from 50% for non‐participants to roughly 43.5% for participants. CONCLUSIONS These findings support the effectiveness of drug courts in reducing recidivism, but the strength of this evidence varies by court type. The evidence finds strong, consistent recidivism reductions in evaluations of adult drug courts. DWI drug courts appear to be strong but this evidence is less consistent, especially in experimental evaluations. More experimental researching assessing the effects of DWI drug courts is clearly needed. For juvenile drug courts, the evidence generally finds small reductions in recidivism. More evaluations of juvenile drug courts, especially experimental and strong quasi‐experimental evaluations, are needed. PLAIN LANGUAGE SUMMARY Drug courts are specialized courts in which court actors collaboratively use the legal and moral authority of the court to monitor drug‐involved offenders' abstinence from drug use via frequent drug testing and compliance with individualized drug treatment programs. The objective of this review was to systematically review quasi‐experimental and experimental evaluations of the effectiveness of drug courts in reducing future offending and drug use. The systematic search identified 154 independent, eligible evaluations, 92 evaluations of adult drug courts, 34 of juvenile drug courts, and 28 of drunk‐driving (DWI) drug courts. The findings most strongly support the effectiveness of adult drug courts, as even the most rigorous evaluations consistently find reductions in recidivism and these effects generally persist for at least three years. The magnitude of this effect is analogous to a drop in general and drug‐related recidivism from 50% for non‐participants to approximately 38% for participants. The evidence also suggests that DWI drug courts are effective in reducing recidivism and their effect on recidivism is very similar in magnitude to that of adult drug courts (i.e., a reduction in recidivism of approximately 12 percentage points); yet, some caution is warranted, as the few available experimental evaluations of DWI drug courts do not uniformly support their effectiveness. For juvenile drug courts we find considerably smaller effects on recidivism. The mean effect size for these courts is analogous to a drop in recidivism from 50% for non‐participants to roughly 43.5% for participants