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.

Annual Baseline King-Devick Oculomotor Function Testing Is Needed Due to Scores Varying by Age

“…Normative data have been utilised extensively in other fields where baseline and pre-injury testing are not feasible [32]. This may be due to limited resources available, the facilities utilised and time factors imposed for the assessment to be conducted [33].…”

“…It has been reported [43] that factors such age, sex, and history of concussion may be risk factors for influencing the results of the K-D test but there is a paucity of studies reporting on the other aspects identified that could also influence the results of the K-D test. As a concussed athlete's post-injury performance would be below the normative values, any retesting results will likely see practice effects on subsequent retesting, necessitating retest normative data to be established [32]. Therefore, although the use of normative data for post-injury evaluation is attractive as it less time and resource intensive, in terms of concussion it does not have the research base established for its use in the field of concussion assessment and management [32].…”

“…As a concussed athlete's post-injury performance would be below the normative values, any retesting results will likely see practice effects on subsequent retesting, necessitating retest normative data to be established [32]. Therefore, although the use of normative data for post-injury evaluation is attractive as it less time and resource intensive, in terms of concussion it does not have the research base established for its use in the field of concussion assessment and management [32].…”

Influence of Test Environment, Age, Sex, and Sport on Baseline Computerized Neurocognitive Test Performance

“…Baseline neurocognitive testing provides clinicians with a preinjury evaluation of neurocognitive performance for comparison with after the injury. Baseline measurements provide better diagnostic accuracy, 13,18 with fewer false-positive results, 23 than normative data. Therefore, it is important for clinicians and researchers to identify factors such as testing environment 17,20 that might negatively affect the accuracy and validity of baseline performance.…”

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

“…In contrast, decline on one SCAT5 test at the 0.95 CI (12.9% of sample) or two or more tests at the 0.80 CI (8.3% of sample) is sufficiently rare to warrant clinical concern supporting possible concussion diagnosis. Documented methods for improving the reliability/accuracy of cognitive measures in sports included: use of multiple baselines74 75; development of cognitive composite scores76–79; use of tests that minimise test ceiling/floor effects; and incorporating measures/procedures to ensure performance validity at baseline 80–85…”