The prediction of Change: Normative neuropsychological trajectories

Abstract

While the application of normative standards is vital to the practice of clinical neuropsychology, data regarding normative change remains scarce despite the frequency of serial assessments. Based on 285 normal individuals, we provide co-normed baseline data with demographic adjustments and test-retest standardized regression based (SRB) models for three time points for several measures. These models delineate normal, expected change across time, and yield standardized z-scores that are comparable across tests. Using a new approach, performance on any previous trial was accounted for in the subsequent models of change, yielding serial normative formulas that model change trajectories rather than simple change from point to point. These equations provide indices of deviation from expected baseline and change for use in clinical or research settings.

Keywords:

• Change
• Trajectory
• Normal change.

Acknowledgments

We wish to acknowledge the considerable work of the many researchers involved in the collection of these data. In particular we thank Paula Bell and Steve Hutton of the University of North Carolina-Chapel Hill (UNC-CH). We would also like to thank Drs. David Savitz, Christine Moe, David Weber, and Paul Stewart, also from the UNC-CH research team when the data were collected and analyzed for the parent study. We would also like to thank Dr. Elizabeth Turf of the Virginia Commonwealth University. Finally, we thank Dr. Carl Pieper of Duke University Medical Center for his invaluable insights during the completion of this project.