A review of factors affecting treatment outcomes: Expected Treatment Outcome Scale

The Expected Treatment Outcome Scales was developed to gather information on clients who abuse drugs or alcohol, to assess their severity of illness, and to evaluate the effectiveness of drug treatment in nonrandomized clinical studies. The scale is based upon a multiattribute value model reflecting the opinions of an expert panel. The experts identified 25 variables, or predictors of relapse, from which 48 questions were constructed. Answers to the questions are individually scored. These scores are summed to produce an overall Expected Treatment Outcome score. This paper focuses on the development and preliminary validation of the Expected Treatment Outcome Scale. Results of our analysis show a correlation of .89 between the experts' average ratings of hypothetical clients and scores based on our scale. This finding suggests that the Expected Treatment Outcome Scale has face validity and accurately simulates the experts' judgments regarding treatment outcome. Further research is necessary to assess the reliability as well as the concurrent and predictive validity of our instrument.