Literature Review - Methadone Maintenance Treatment

8. Research and Evaluation

According to Bell (1998a, 161) there is a great disparity between research and practice in methadone maintenance treatment, and the major factor in this disparity is "profound disagreement over such basic issues as the nature of the problem being treated and the goals of treatment." Bell (1998a, 162) emphasizes the need for research and treatment to share a common "frame of reference" for making observations, generating hypotheses, and evaluating clinical practices. The lack of such a frame explains "why, despite extensive research validation, methadone maintenance continues to be referred to as 'controversial."

There are many important reasons for conducting more research on methadone maintenance treatment. For example, making methadone maintenance more client/patient-centred, and conducting research on outcomes that are priorities for clients/patients are key areas (Hall et al., 1998a, 3-4). Making substance use treatment "more attractive and acceptable to the general public, as well as to decision makers and funding agencies" (Stoller & Bigelow, 1999, 33) by evaluating the cost-effectiveness and benefits of treatment is an another important area of study.

Numerous research gaps were identified in the literature reviewed for this report. Examples include the need to assess methadone maintenance treatment's impact on the "containment" of HIV transmission, an area which has been "less investigated" than other outcomes such as the impact on illicit drug use, injection drug use and criminal acts (Hall and Mattick, 1998a, 3); and the need to determine methadone maintenance treatment's impact on improving the health and social well-being of people who are dependent on opioids (Hall, 1998a, 4). Relatively few studies have examined the extent to which methadone maintenance treatment plays a role in the prevention of hepatitis B and C (Ward et al., 1998g, 60) and this is another area where research is needed.

There is a valuable, but limited, body of research on delivering MMT programs to specific populations with diverse needs. In particular, more research is needed on effective strategies to address the needs of those who use multiple substances, women, pregnant women, people suffering from comorbid medical conditions (including those who have acquired HIV, HCV or other blood-borne pathogens) and/or mental health disorders. Implementing and evaluating the effectiveness of MMT delivery strategies within correctional settings remains another challenge.

Further investigation into economic aspects of MMT would also be valuable. For example, Ward and Sutton (1998, 92) suggest that: "Economic evaluations that look at both the cost and the consequences of intervening will prove to be more valuable in persuading those charged with the responsibility of determining the appropriate allocation of resources of the value of methadone maintenance treatment." They also note that cost-of-illness studies do not indicate whether or not there are interventions that can cost-effectively reduce the burden of illness identified (Ward and Sutton, 1998, 95). The National Consensus Development Panel on Effective Medical Treatment of Opiate Addiction, (1998, 1941) identified the need for further study of the economic costs of opioid dependence and the cost-effectiveness of methadone maintenance therapy.