Clinical versus reliable and significant change

Sheldrick, Kendall, and Heimberg have illustrated and compared the use of the reliable change index (RCI) and normative comparisons procedures for assessing the clinical meaningfulness of research findings. Their presentation illustrates how the method of normative comparisons, combined with a reliability of change index such as that offered by Jacobson and colleagues can be used to assess the clinical meaningfulness of treatments. Their comparisons of treatments that have been previously identified as empirically supported reveal that a definition of worth, based on statistical significance, fails to identify the power (or lack thereof) of the intervention. Reliable change and clinical meaningful change estimates add substantially to the interpretation of statistical significance. However, they are complementary, not equivalent methods. The RCI can only indicate whether the change noted exceeds what can be expected because of the unreliability of the instrument used. Although estimates of clinical utility should be routine in research reports of treatment effects wherever possible, there are still situations in which procedures for estimating clinical significance are lacking, and new methods are needed in these instances.