Is it sandbagging or is it just apathy? Baseline ImPACT and external validity indicators in collegiate athletes

Objective Baseline cognitive testing is important for sport concussion management. Assessing performance validity during baseline testing is vital to ensure an athlete provides best effort. Stand-alone performance validity tests and embedded validity indicators (collectively called “effort measures” hereafter) are commonly used. This study further investigates efficient ways to assess variable effort in baseline cognitive testing. Methods 231 NCAA athletes completed baseline assessment with ImPACT and one of two stand-alone effort measures: Medical Symptom Validity Test or Rey Dot Counting Test. The relationship between effort and cognitive performance, symptoms, and sleep was assessed. Results Athletes who failed two or more effort measures performed worse on the Visual Motor Speed Composite while athletes failing three or more measures performed worse on the Reaction Time Composite. Those athletes who failed effort measures and also reported poor sleep performed worse on both composites. Self-reported symptoms and hours of sleep were not independently associated with failing effort measures. Lastly, athletes with ADHD and/or LD were more likely to fail two+ indicators (46% versus 27% of neurotypical athletes). Conclusions Consistent with previous research, ImPACT Baseline++ only identified 1.7% of our sample as poor effort despite 4.8% failing a combination of stand-alone/embedded effort measures and an additional 42.9% failing at least one embedded measure alone. Results suggest that assessing effort on a continuum and using multiple effort measures may be useful to identify suboptimal effort for non-intentional reasons. Public Significance Statement Baseline ImPACT testing is common and often mandated prior to sport participation, however, valid baselines require athletes to provide their best effort. This study adds to the growing body of literature demonstrating that athletes frequently do not provide best effort on baseline testing. Additionally it suggests that athletes may not be intentionally underperforming, as stand-alone performance validity tests miss a significant number of athletes who have other indicators of poor effort within their ImPACT baselines. ### Competing Interest Statement The authors have declared no competing interest.