Clinically significant change: practical indicators for evaluating psychotherapy outcome.
Tingey, Lambert, Burlingame, and Hansen (1996) argue that although there are benefits and utility of clinical significance, extensions to the concept proposed a decade ago (Jacobson, Follette, & Revenstorf, 1984a) are necessary. The criticisms of the original paper and subsequent extensions are problematic and fail to appreciate the underlying principle of clinical significance, namely defining for whom and for what purpose significant change would be identified. This paper responds to several of the criticisms outlined in Tingey et al. with regard to operationalizing a comparison group, the perceived limitations of using two distributions, and the problems with their approach of specifying a method for determining whether groups are distinct. We then propose that there is a principle that underlies the concept of clinical significance that should be appreciated. We conclude by describing under what conditions "functional" distributions may be supplemented by including information to allow comparisons of outcomes with the current best available treatment alternative, but offer a cautionary statement about the potential risks run by extensions such as Tingey et al.'s that can obscure the concept of clinical significance to the point that researchers are no longer discussing change in terms meaningful to the client.