A method for assessing clinically relevant individual cognitive change in older adult populations

The evaluation of individual cognitive change has relied heavily upon the raw change score, defined simply as the difference between follow-up and baseline scores. However, raw changes scores are susceptible to the confounding effects of both regression-to-the-mean and practice effect. The clinical relevance of raw change scores for the older adult is also obscured by normal, age-related cognitive change. The present study illustrates the use of a standardized regression-based (SRB) methodology to generate an alternative to the raw change score; the SRB change score. SRB change scores provide a standardized alternative to the raw change score, allowing the clinician to evaluate the magnitude of change on one or more variables along a common metric that controls for practice effect, regression-to-the-mean, and normal cognitive decline. Case data illustrate how SRB change scores can identify clinically relevant cognitive change in the individual older adult patient.