At 12 months post-release, Wexler, De Leon, Thomas, Kressel, and Peters (1999) found the no-treatment control group had significantly greater levels of reincarceration than the intent-to-treat group (49.7 percent versus 33.9 percent, respectively). The reincarceration rate was higher for the control group, and the rate decreased consistently across the four treatment study groups. Within the intent-to-treat group, inmates who completed both the prison and aftercare therapeutic community (TC) showed the lowest rate of reincarceration (8.2 percent).
This potential confounding effect of residential status is less of a factor in the 24-month follow-up period. At 24 months post-release, the no-treatment control group had significantly greater levels of recidivism than the intent-to-treat group (67.1 percent versus 42.2 percent, respectively). The aftercare TC dropouts showed an increase in reincarceration rates, but it was a non-significant reversal, and the group still maintained a success rate that was 7 percent better than the no-treatment control group. The inmates who completed both the prison and aftercare TC programs had a low reincarceration rate of 14 percent at 24 months, which was more than 12 months after completing aftercare TC treatment.
Multivariate analysis showed that 12 months after release from prison, the intent-to-treat group had a significantly lower reincarceration rate. Compared to the control group, inmates who had any level of participation in the prison TC treatment program were 48 percent less likely to be reincarcerated within 12 months after release to the community. At 24 months post-release, inmates who participated in TC treatment were 37 percent less likely to be reincarcerated following release from prison.
Days Until Reincarceration
Compared to the intent-to-treat group, the no-treatment control group had significantly fewer days until reincarceration. After 12 months at risk following release from prison, the control group had an average of 172 days until return to prison, compared to an average of 192 days for the intent-to-treat group. The greatest difference in days until reincarceration was found for the group that completed aftercare TC treatment compared to the no-treatment control group (274 mean days versus 172 mean days, respectively). Again, this result could be confounded by the fact that aftercare TC completers were in residential treatment for most of the 12 month post-release period.
As with the examination of the reincarceration rates, however, this factor is less of an issue over the 24-month period of risk. At 24 months, the aftercare TC completers had an average of 391 days until reincarceration, while the control group had an average of 216 days until reincarceration.
Overall, the reincarceration rates and days until reincarceration show a similar pattern of positive results. The full intent-to-treat group showed significantly more positive effects than the no-treatment control group. Within the intent-to-treat group, the post-release outcomes are generally related to increased involvement in treatment. The most favorable outcomes occurred for inmates who completed both the prison TC and the aftercare TC program.
Wexler, Melnick, Lowe, and Peters (1999) found that at 36 months, the intent-to-treat group showed lower rates of reincarceration than the control group; however, the difference was not statistically significant. A significant difference does emerge when looking at the intent-to-treat subgroups. Only 27 percent of the aftercare completers were reincarcerated, in contrast to more than three fourths of the prison TC completers (with no aftercare), prison dropouts, and controls.
The study also found that when controlling for background variables (including age and the number of previous incarcerations), aftercare completers were 6.2 times less likely than the program completers and 4.3 times less likely than the program dropouts to return to prison. There was no significant difference in the likelihood of returning to prison between the prison TC dropouts and prison TC completers.
Days Until Reincarceration
Overall, the results showed that the number of days to reincarceration increased significantly across the intent-to-treat subgroups, indicating that increased amounts of treatment resulted in a greater number of days to reincarceration. It took significantly longer for the aftercare completers to recidivate than either the program dropouts or program completers. The aftercare completers took an average number of 578 days to return to prison, while program completers had an average number of 386 days and program dropouts had an average number of 305 days. By comparison, the control group had an average number of 295 days to reincarceration.
When controlling for background variables, there was a significant relationship between increasing the amount of treatment and the amount of time until reincarceration. Thus, the longer the treatment duration, the longer the inmate remained on parole prior to a first return to prison.
Although Prendergast and colleagues (2004) found some significant differences between the groups when examining the outcomes of reincarceration using bivariate analysis, multivariate analysis did not find significant differences. Instead, other factors (age and postrelease treatment) became significant predictors of reincarnation. Also, there were no significant differences on measurements of heavy drug use and employment over the 5-year follow-up period. There were some significant differences on employment and reincarceration rates when looking at the subgroups, but no significant differences on heavy drug use.
There was a significantly smaller percentage of the treatment group that was reincarcerated compared to the control group. For the treatment group, 75.7 percent had at least one reincarceration over the 5 years, compared to 83.4 percent of the control group. The survival analysis, looking at the number of days from release to reincarceration, also showed a significant difference between groups. The treatment group spent an average of 6 months longer on the street following release than did those in the control group (809 and 634 days, respectively).
However, the Cox regression analysis found that group status (treatment group or control group) was not significantly associated with time to reincarceration. The two factors that predicted delayed incarceration were being older and the number of months attending treatment since release. The survival curves, after controlling for certain variables, for the treatment and control groups began to merge after approximately 2 years.
Heavy Drug Use
The percentage of treatment group and control group members who reported using drugs heavily during the year before the interview was not significantly different and nearly identical (24.93 percent for the treatment group and 22.55 percent for the control group).
Self-reported employment in the year before the interview was also not significantly different between the two groups (54.84 percent for the treatment group and 52.34 percent for the control group).
The prison program dropouts and the prison program completers had similar percentages of return to custody (87 percent and 86 percent, respectively). The VISTA dropouts had a slightly lower reincarceration rate (81 percent) but those who completed the continuum of treatment had a significantly lower reincarceration rate of 42 percent. The survival analysis found that Vista completers took 1,369 days to return to prison, compared to 618 days for the prison TC dropouts, 636 days for the prison TC completers, and 795 days for the Vista dropouts.
The results for drug use showed that participants in the four treatment subgroups reported using drugs heavily in the past year, although at relatively low rates. Over the 5-year period, 24.7 percent of the TC dropouts, 27.7 percent of the TC completers, 19.2 percent of the Vista dropouts, and 21.5 percent of the Vista completers reported heavy drug use in the past year. The differences were not significant. The differences between the groups were significant for employment. Seventy-two percent of the Vista completers, 40 percent of the prison TC dropouts, 56 percent of the TC completers, and 38 percent of the Vista dropouts reported having been employed.