Explaining abstinence rates following treatment for alcohol abuse: a quantitative synthesis of patient, research design and treatment effects.

We examined the relationships of treatment, patient and research design characteristics to treatment outcome (i.e. abstinence rates) in a sample of 150 treatment conditions drawn from 100 alcohol treatment outcome studies published between 1980 and 1992. Treatment characteristics were related to abstinence rates: more intensive treatments had higher abstinence rates than less intensive treatments, whereas treatments with an expressed goal other than abstinence had lower abstinence rates than treatments with an abstinence goal. When the public vs. private ownership status of the treatment facility was taken into account, the presence of behavioral elements in the treatment condition also was related to higher abstinence rates. Because of inconsistent reporting in primary studies, we assessed the effects of only one patient pre-treatment characteristic; treatment conditions with a higher proportion of socially stable patients had better outcomes. Research design characteristics were also related to abstinence rates. Treatment conditions with shorter follow-ups and treatments drawn from studies that did not use criteria to exclude more impaired subjects had better outcomes. We discuss possible reasons why our findings regarding the effects of treatment intensity and the use of exclusionary criteria differ from those in previous reviews.