The results highlight the importance of selection bias – the distortion of a statistical analysis by self-selection of participants. Individuals who come forward to take part in trials such as Project MATCH might be more likely to have positive outcomes. "Alcoholics who decide to enter treatment are likely to reduce drinking. Those who decrease their drinking are more likely to remain in treatment", explain Robert Cutler and David Fishbain from the department of psychiatry and behavioural sciences at the University of Miami, the authors of the study.
A fundamental principle underlying the treatment of alcoholism, and other addictions, is that psychosocial therapy - therapy involving both group meetings and personalised sessions with psychologists - is effective.
Cutler and Fishbain re-examined data from Project MATCH – a large trial carried out in the late 1990's, which concluded that therapy for alcoholism produced excellent outcomes, although the results were controversial and inconclusive.
Project MATCH assessed the effectiveness of three different therapies: Cognitive Behavioural Therapy (CBT), Motivational Enhancement Therapy (MET) and Twelve Step Facilitation (TSF). Cutler and Fishbain investigated the relationship between the number of therapy sessions attended and how successful project MATCH participants had been at reducing and abstaining from drinking. For all patients, drinking outcome was measured in two ways, percent days abstinent (PDA) and drinks per drinking day (DDD).
In one analysis, the participants of the study were divided into three groups: those who had attended either none, one, or all twelve of the treatment sessions. Overall, Cutler and Fishbain's data showed that participants who attended all twelve sessions had better outcomes, but there was only a very slight improvement over participants who attended no sessions. For participants who attended the twelve treatment sessions, PDA increased by 60% almost immediately, at week one, but increased by only a further four percent during the following 11 weeks of treatment. The researchers also found that participants who dropped out before the program even began had significantly better outcomes at the end of the program than those who dropped out after one session. In the long-term, the number of treatment sessions attended had a poor correlation with the outcome.
From the data, the authors conclude that "current psychosocial treatments for alcoholism are not particularly effective", and that "most of the improvement which is interpreted as treatment effect is not due to treatment". The authors attribute their findings to the importance of 'self-selection'; i.e., that patients who reduce their alcohol consumption are more likely to enter or remain in treatment, and those who are drinking are more likely to drop out of treatment. According to the authors if these patient characteristics are more important than attendance at therapy, then this "would have a profound influence on alcoholism treatment because it would shift focus away from treatment components and toward patient characteristics".
This press release is based on the article:
Are alcoholism treatments effective? The project MATCH data
Robert B Cutler and David A Fishbain
BMC Public Health 2005, 5:75 (14 July 2005)
This article is available free of charge, according to BMC Public Health's Open Access policy at:
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