Assessing clinical significance: does it matter which method we use?

Measures of clinical significance are frequently used to evaluate client change during therapy. Several alternatives to the original method devised by N. S. Jacobson, W. C. Follette, & D. Revenstorf (1984) have been proposed, each purporting to increase accuracy. However, researchers have had little systematic guidance in choosing among alternatives. In this simulation study, the authors systematically explored data parameters (e.g., reliability of measurement, pre-post effect size, and pre-post correlation) that might yield differing results among the most widely considered clinical significance methods. Results indicated that classification across methods was far more similar than different, especially at greater levels of reliability. As such, the existing methods of clinical significance appear highly comparable; future directions for clinical significance use and research are discussed.