In a 2003 report, New York's Center for Court Innovation examined eleven different adult drug courts in New York state. They found that "Relapse and noncompliance are common, even among those who ultimately succeed. In seven of eight courts examined, at least half of all graduates had at least one positive drug test, and many had several positives - usually in the earlier stages of participation. This highlights the value of drug courts according multiple chances to participants experiencing early problems."

Source

Rempel, Michael, Dana Fox-Kralstein, Amanda Cissner, Robyn Cohen, Melissa Labriola, Donald Farole, Ann Bader and Michael Magnani, "The New York State Adult Drug Court Evaluation: Policies, Participants and Impacts" (New York, NY: Center for Court Innovation, Oct. 2003), p. xiv.
http://www.courtinnovation.or…