Reviewing the evidence, we conclude that the randomized controlled trial has not yet been used to full advantage in treatment evaluation research. Other reviews have stressed the clear value of non-experimental observational studies to evaluate treatment. Without gainsaying the value of these studies, this committee’s emphasis is different. Some very informative randomized control trials have been completed, but more trials are needed to fill gaps in evidence that cannot be filled definitively with nonexperimental studies. This chapter reviews the research literature with special emphasis on this important gap.
We begin with three observations about the kinds of information that policy makers need.
First, there is no single entity or process called “drug treatment.” Rather, there are a plethora of therapies, modalities, and delivery systems: public and private, in-patient and outpatient, voluntary and coerced, talk-based and psychopharmacological, individual and group, cognitive and behavioral, and so on. Clients, family members, and practitioners need guidance as to the most effective strategies for a given client and setting, at an affordable cost. Policy makers and treatment funders need guidance as to the most cost-effective strategies or combinations of strategies.
Second, a very large fraction of the most heavily involved drug users come into contact with the criminal justice system, and many are incarcerated or under the supervision of probation or parole officers. For example, in 1996, 24 percent of jail inmates reported using cocaine or crack in the month before their most recent offense; 9 percent reported heroin or opiate use, and 10 percent reported stimulant use (Sourcebook of Criminal Justice Statistics, 1998, Table 6.33, http://www.albany.edu/sourcebook/1995/pdf/t633.pdf). Policy makers need better information on the benefits of drug treatment as an adjunct to, or an alternative to, traditional criminal justice sanctions.
Third, somewhere between 3.5 and 6.7 million people in the United States are in need of effective drug treatment (see Woodward et al., 1997; Epstein and Gfroerer, 1995). Only a minority of those who need drug treatment are currently receiving it—somewhere between 20 percent (Lamb et al., 1998) and 48 percent (Woodward et al., 1997). Fewer than 200,000 individuals currently receive methadone maintenance,1 yet it is believed that there are 600,000 to 1,000,000 heroin addicts in the United