"As shown in Table 4-3.4, offenders in the drug court used drugs significantly less often than did offenders in the comparison group during the initial six-month tracking period. Overall, 40 percent of drug court participants as compared with 55 percent of comparison offenders reported that they had used at least one of the eight measured substances (p < .05). Drug court offenders also averaged fewer days of drug use per month (1.5 vs. 3.7 days; p < .01) and fewer days of serious use per month (1.0 vs. 2.2 days, p < .05).3 Regarding specific illegal substances, 13 percent of the drug court sample had used marijuana versus 26 percent of the comparison group (p < .05). One- third (32 percent) of the drug court sample reported drinking alcohol compared to more than half (52 percent) of the comparison group (p < .05). A significantly lower percentage of drug court offenders also reported illegal prescription drug use (6 percent versus 10 percent; p < .05). Analogous findings were detected when isolating drug use in just the most recent month prior to the six-month survey. Finally, drug court and comparison offenders had, on average, similar six-month scores on the Addiction Severity Index (5.4 versus 5.0; non-significant) and experienced similar reductions between baseline and six months (-4.0 vs. -3.7; n.s.)."

Source

Rossman, Shelli B., et al., "Final Report, Volume 4: The Multi-Site Adult Drug Court Evaluation: The Impact of Drug Courts" (Washington, DC: Urban Institute, June 2011), p. 33.
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