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Informing America’s Policy on Illegal Drugs: What We Don’t Know Keeps Hurting Us
(Belenko, 1998; U.S. General Accounting Office, 1997). First, there are enormous variations in eligibility requirements and program characteristics. Second, the U.S. General Accounting Office found that a majority of programs tended to assess recidivism and not relapse or, less frequently, relapse but not recidivism. Third, most of the existing studies are uncontrolled comparisons involving before-after or nonrandomized comparison groups, with the kind of threats to internal validity discussed earlier in this chapter. While many of these studies report reductions in drug use or criminal recidivism, it is notable that neither result clearly emerged in a rigorous study using random assignment to either drug courts or standard probation (Deschenes et al., 1995).
A Proposed Example
There is a clear need for more rigorous experiments on the effects of drug treatment as an alternative or adjunct to criminal justice sanctions. In the committee’s judgment, such experiments are logistically feasible and can be designed to be ethically defensible. Here we offer an example of a possible experiment by way of illustration.
A population of prisoners incarcerated for drug-related crimes could be randomized prior to release from prison. They would be segregated first by drug use category (heroin addicts, cocaine addicts, cocaine/alcohol, cocaine/heroin, etc.). The specific treatments for each category would differ. Subject characteristics to be assessed prior to release would include Addiction Severity Index scores, educational level, prior employment history, marital status, and other risk factors for drug relapse.
Within each category, one group of subjects would be randomized to follow-up as usual by the parole system with no contact with either treatment or research. Evaluation data at each visit would be obtained by a parole officer. Prisoners would be randomly assigned to one of three groups: (1) standard parole; (2) Treatment A; (3) Treatment B. A patient assigned to Treatment A could refuse treatment and receive standard parole instead, but this patient would remain part of the Treatment A group. Similar procedures would be followed for Treatment B. This is Marvin Zelen’s (1979) randomized consent design.
It is likely that some subjects assigned to standard parole will enter treatment on their own, and some other assigned to groups A or B will refuse treatment; this fact would have to be considered in the data analysis.
Similarly, the predictor variables obtained prior to randomization would have to be assessed, to determine the comparability of the four groups and for use as covariates in analysis of outcome data.