From the general to the specific. Using meta-analytic reports in clinical decision making

The purpose of this article is to describe how health practitioners can interpret the results from published meta-analytic reports of intervention effectiveness and efficacy studies, and then communicate those results, in a manner that helps patients make critical clinical and life decisions. The problem of using research evidence in clinical decision making is one of moving from generalized findings about intervention effectiveness to a prediction for a specific patient. To move toward a reasonable prediction, practitioners need information from a meta-analytic report that enables them to identify and understand the distribution of outcome results that are most applicable to a specific patient. Relevancy, effectiveness, and interpretation forms of information are discussed in this article. The focus is on the interpretation of the effect size statistics d and r for understanding the variation in responses that the patient might experience with an intervention.