Performance validity tests (PVTs) provide a methodological approach to detecting credible neurocognitive performances. This proves invaluable to the diagnostic process, as it allows neuropsychologists to objectively determine if an evaluation reflects a patient’s true neurocognitive abilities or if external factors are impacting the results. However, their addition to a testing battery can increase an already lengthy evaluation. As such, there is a need for sensitive but less time intensive PVTs. The purpose of this study is to validate the Coin-in-Hand (CIH) procedure as a quick and effective PVT within a veteran population.

68 English-speaking patients were identified from an outpatient neuropsychological assessment dataset. Performances were correlated to the well- validated Reliable Digit Span (RDS), and several other soft indicators of task engagement including expanded COWAT, BVMT-False Alarms (FA), WCST Failure to Maintain Set (FTM), TOMM, and the RBANS Effort Index (EI). All participants attempted CIH and RDS, testing was discontinued if 2 or more PVTs were invalid. An AUC analysis was conducted to determine how well the CIH discriminated between valid and invalid performance and determine the tests optimal cut-off score (sensitivity > 0.90 while maintaining the highest possible specificity). Logistic Regression was conducted to determine how well the CIH predicted performance validity.

Subject mean(SD) age and education were 55.25 (16.06) and 13.41 (2.55) years, respectively. 17% female, 60% Caucasian, and 32% Black. Descriptive statistics for each of the other performance validity tests were gathered. The CIH demonstrated low diagnostic accuracy (AUC = .66; p >.05; CI = .51 -.81); a cut score of <8 resulted in a sensitivity of .96 and a specificty of .64. Logistic Regression showed that CIH performance significantly predicted performance validity (X2 = -0.93; df = 1; N = 68; p < .05), accounting for 18-28% of the variance in performance classification (Cox & Snell R2 = .18; Nagelkerke R2 = .28). It correctly classified 96% of valid performers, but only correctly classified 35% of invalid performers, with an overall correct prediction rate of 83%. A predicted chase in log odds (B= -.93) and odd ratio [Exp (B) =.40] indicated that every unit increase in CIH score was associated with a decrease probability of performance invalidity. Logistic regression was also used to calculate the probability of performance invalidity at each possible CIH score (Table 1).

Results suggests that poor performance on CIH does not necessarily equate to invalid performances, but instead, should act as a screener to cue neuropsychologists working with Veterans that additional PVTs should be considered. Overall, it was determined that CIH was able to correctly predict 35% of invalid performers and 96% of valid performers, with an overall correct prediction rate of 83%, suggesting the procedure may be too simple to be an effective standalone PVT for clinical use. These results also highlight that every correct response on the CIH was associated with a decreased probability of performance invalidity. Additionally, an AUC analysis determined the tests optimal cut off score to be <8, suggesting that shortening the procedure may be as effective as giving the full 10 trials.