The analyses by Martin, Butzin, and Inciardi (1995) showed that the KEY–Crest and Crest–only groups were significantly more likely to be drug-free and arrest-free at follow-up than the KEY–only and the no-treatment groups. The differences between the KEY–only group and the comparison group on both measures were not statistically significant, however.
Drug Use and Arrest Status
To account for differences between the study groups that may affect measures of drug use and arrest, a second analysis controlled for other predictors of arrest and drug use, such as criminal history, prior drug use, and time in treatment. The outcome measures for drug use and arrest showed that participating in KEY–Crest and Crest still resulted in significantly better outcomes relative to the comparison group. However, for both outcome measures, the KEY group was not statistically different from the comparison group. The results suggest that TC treatment without a transitional work release or aftercare component is not as effective.
The rate of injection drug use was significantly reduced for the Crest–only group. Although the rate of injection drug use was also substantially reduced for the KEY–Crest group, the effect was not statistically significant. There was no apparent benefit for the KEY–only group.
For condom use, both the KEY–only and KEY–Crest groups showed a significantly higher use. The Crest–only group showed a higher use rate then the comparison group, but it was not statistically significant.
Drug Use and Arrest Status, Original Grouping
When looking at the original four study groups (KEY–only, KEY–Crest, Crest–only, and the comparison group), Martin and colleagues (1999) found that the KEY group was not significantly different from the comparison group in measures of arrest-free and drug-free status. For arrest-free status, there is a small but insignificant benefit of TC treatment versus the comparison group, but there were no differences among the three TC groups. For drug-free status, TC treatment in each of the three groups does produce a significant increase in the probability of being drug-free, as opposed to the comparison group. However, among the TC groups, there are no differences in the likelihood of being drug-free. The results would suggest there are modest benefits for some TC treatment as compared to no TC treatment, but there’s no indication that the probability of remaining drug-free and arrest-free increases with more stages of TC treatment. This is in contrast to results from the previous study, which found TC treatment with work release and aftercare components to be more beneficial to program participants than just TC treatment.
Drug Use and Arrest Status, New Grouping
When looking at the new grouping of study participants (Crest dropouts, Crest graduates with aftercare, and Crest graduates without aftercare), the results are somewhat different. Crest dropouts are just as likely to be arrested on a new charge as the comparison group. However, those who complete Crest do much better, and those who complete Crest and receive aftercare are the least likely to have a new arrest. For drug-free status, Crest dropouts are more than three times as likely to be drug-free, Crest completers more than five times as likely, and Crest completers with aftercare are seven times more likely to be drug-free versus the comparison group.
Drug Use and Arrest Status at 42 Months
Inciardi, Martin, and Butzin (2004) found that participation in the transitional treatment program more than quadrupled the odds of remaining drug-free at 42 months. Treatment participation was also a significant predictor of criminal recidivism. There was a 70 percent reduction in the odds of a new arrest for those assigned to treatment.
Drug Use and Arrest Status at 60 Months
The results for drug use and rearrests at 60 months were similar to the results at 42 months. Participation in the transitional treatment program still more than tripled the odds of remaining drug-free. Additionally, study participants with no previous treatment were more likely to relapse, while those who received treatment were significant less likely to relapse. Treatment participation was also a significant predictor of no new arrests at 60 months.
Drug Use and Arrest Status, All Treatment Group
A second analysis broke out the All Treatment Group into three separate groups: dropouts, graduates without aftercare, and graduates with aftercare, and compared the outcomes to the control group that did not receive treatment. The results showed consistent effects through the follow-up periods. Study participants who completed TC treatment with or without aftercare had significantly greater probabilities of remaining both arrest-free and drug-free at both time points than did those without treatment. Those program participants who did complete treatment and attended aftercare were the least likely to have a new arrest or to have relapsed into drug use. Just under half of those who completed treatment and then attended aftercare would be expected to have a new arrest, compared to more than 75 percent of the group without treatment. Those in the treated groups were 15 to 20 times more likely to be drug-free compared to the group without treatment.