ISAP Research Projects
Name of Project: Evaluating Voucher-based Contingencies
in a Drug Court
Principal Investigator: Michael Prendergast,
Ph. D.
Co-Principal Investigator/Project Director:
John Roll, Ph. D.
Funding Agency: National Institute on Drug Abuse
(NIDA)
Funding Period: September 1999-August 2004
Scope of Project: Drug court defendants who agree
to participate in the Evaluating Voucher-based Contingencies in
a Drug Court study are randomly assigned to one of four groups
shortly after admission to the drug court treatment program, with
60 participants in each group. The standard treatment program
serves as a “platform” for the evaluation of the two
contingency management approaches as supplemental interventions.
The two variables being evaluated are contingent vouchers for
drug-free urine samples (drug-testing variable) and contingent
vouchers for completion of assigned treatment plan tasks (treatment
plan variable). The resulting four conditions are: (1) standard
drug court treatment, no vouchers (Standard Group); (2) standard
drug court treatment plusvouchers contingent upon testing negative
for illicit drugs (Drug-Testing Group); (3) standard drug court
treatment plus vouchers contingent upon completing specific, verifiable
treatment tasks designed to promote abstinence and recovery (not
including negative drug tests) (Treatment Plan Group); and (4)
a combined group that receives standard drug court treatment plus
vouchers contingent upon testing negative for drugs and/or completing
treatment plan tasks (Combined Group). These interventions will
be in effect during the first 6 months of a 12-month drug court
treatment program that has been operated by Matrix Institute since
July 1998. The study will obtain baseline data at intake and will
assess the impact of vouchers on program retention, drug use,
crime, and other behaviors at three assessment points.
For more information, contact Michael Prendergast.
Last updated - 07/23/2003
Last reviewed - 07/22/2003