Utility of the Standardized Assessment of Concussion (SAC) to Detect Insufficient Effort in Independent Medical Examinations and Civil Litigation Cases

Objective: The Standardized Assessment of Concussion (SAC) is a standardized mental status screening instrument initially developed for assessment and tracking of concussion symptoms in athletes. The purpose of the current study was to validate the utility of the SAC as an embedded screening measure for insufficient effort in independent medical examinations (IME) and personal injury cases. Method: A known-groups design was used to examine the SACs utility for the detection of insufficient effort in 75 de-identified private IME and civil litigation evaluations. Initial classifications of insufficient effort were made independently of SAC scores, on the basis of having two or more scores falling below established cut-offs on previously validated neuropsychological measures. Results: Results suggest that the total score on the SAC significantly distinguishes effortful respondents from those exhibiting insufficient effort. Empirically derived cut-off scores yielded adequate sensitivity (.62-.95) and negative predictive power (.93-.97). Conclusions: While optimal cut-off scores depend upon intended use, our data suggest that the SAC is useful as a potential screener for insufficient effort, after which one can employ additional measures to rule out false-positives. Further research is required before cut-off scores can be recommended for clinical use.