2006 Volume 29 Issue 3 Pages 33-38
There has been a paradigm shift from an “experimenting society,” which is guided by evidence produced by successive implementation of primary studies, such as random controlled trials (RCTs), to an “evidence-based society,” which is enlightened by evidence accumulated by secondary studies, such as systematic reviews (SRs). This shift is facilitated by the recognition that SRs can provide evidence with a stronger external, construct, and statistical conclusion validity than single RCTs can. The Campbell Collaboration, an international project that is intended to produce evidence by SRs, is expected to play an important role in this movement toward an evidence-based society.
Two approaches to evidence utilization have thus far been developed in the U.S. In the first approach, practitioners are directed to adopt model programs selected by experts on the basis of the results of RCTs and/or SRs. In the second approach, practitioners are expected to design their programs based on a combination of elements found to be effective by SRs. Since the evidence that is disseminated by the second approach is more robust in various contexts, this appears to be more promising. Finally, the power of policy-makers and the media to influence a practitioner's decision to utilize evidence has been highlighted.