Detecting Sandbagging Performance on CNS Vital Signs Concussion Baseline Testing

Abstract

Abstract Purpose To determine CNS Vital Signs validity indicator accuracy in detecting coached suboptimal performance (i.e. sandbagging) on neurocognitive testing. Methods Fifty college-aged students (age=20.8–1.1 years, range 18–25) were randomly assigned to two groups of 25. We compared neurocognitive test performance for two groups completing CNS Vital Signs instructed through verbal scripts to either (1) try their best (control) or (2) purposely sandbag. Participants rated their effort after completing neurocognitive testing on a Visual Analog Scale (0mm=no effort, 100mm=maximum effort). A one-way MANOVA was used to determine domain score differences between the control and sandbagging groups (alpha=0.05) and percent flagged as invalid. A series of ANOVA’s was used to post-hoc the MANOVA. Results Significant raw domain score group differences were identified (V=0.67, F=7.13, p<0.001) such that the sandbagging group performed significantly worse on visual memory, psychomotor speed, reaction time, complex attention, cognitive flexibility, processing speed, executive function, and motor speed compared to the control group. Built-in CNS Vital Signs invalidity indicators successfully identified approximately 70% (17/25) of coached sandbaggers. Approximately 12% of control group participants (3/25) fell below the validity cutoff for simple attention despite instructions to perform their best. All participants on average reported less than optimal effort (mean= 6.8–2.5). Conclusion Built-in CNS Vital Signs validity indicators do an overall good job at identifying those attempting to purposefully sandbag the test. Given that 30% of intentional sandbaggers went undetected, clinicians should consider additional safeguards beyond test algorithms to detect these individuals at baseline.