Normative Versus Baseline Paradigms for Detecting Neuropsychological Impairment Following Sports-Related Concussion

Abstract

Objective: Obtaining baseline neuropsychological (NP) data to assist management of sports-related concussion has been considered the standard of care. The validity of this approach has been questioned, with suggestions that post-concussion testing alone will suffice. The present study compared the sensitivity of baseline and normative paradigms in the setting of sports-related concussion.Method: Baseline NP data were collected for 194 Australian rugby league athletes on a brief battery of paper-and-pencil NP tests. During competition, 27 athletes sustaining concussion referred from a sports physician were retested within two days of injury. Twenty-six uninjured controls were assessed at similar intervals. The baseline paradigm was assessed using a reliable change index for pre- and post-concussion scores. The normative paradigm was assessed comparing the post-concussion score to a normative mean.Results: The baseline paradigm was consistently more sensitive to negative change following concussion than the normative paradigm when using continuous data, despite reasonable agreement. However, when data were categorised as ‘impaired’ or ‘not-impaired’, using either 68% or 90% confidence intervals, the difference between paradigms failed to reach significance. Comparison of ROC curves for both paradigms found superior overall classification for one test and the composite score using baseline comparison data.Conclusions: Despite being a time and resource intensive process, the baseline paradigm as a repeated-measures design may be more sensitive than the between-subjects design of the normative paradigm for detecting changes following concussion. Further work is required to determine the validity of normative assessment in sports-related concussion.