Assessment of differential neurocognitive performance based on the number of performance validity tests failures: A cross-validation study across multiple mixed clinical samples.

This cross-sectional study examined the effect of number of Performance Validity Test (PVT) failures on neuropsychological test performance among a demographically diverse Veteran (VA) sample ( = 76) and academic medical sample (AMC;  = 128). A secondary goal was to investigate the psychometric implications of including versus excluding those with one PVT failure when cross-validating a series of embedded PVTs. All patients completed the same six criterion PVTs, with the AMC sample completing three additional embedded PVTs. Neurocognitive test performance differences were examined based on number of PVT failures (0, 1, 2+) for both samples, and effect of number of criterion failures on embedded PVT performance was analyzed among the AMC sample. Both groups with 0 or 1 PVT failures performed better than those with ≥2 PVT failures across most cognitive tests. There were nonsignificant differences between those with 0 or 1 PVT failures except for one test in the AMC sample. Receiver operator characteristic curve analyses found no differences in optimal cut score based on number of PVT failures when retaining/excluding one PVT failure. Findings support the use of ≥2 PVT failures as indicative of performance invalidity. These findings strongly support including those with one PVT failure with those with zero PVT failures in diagnostic accuracy studies, given that their inclusion reflects actual clinical practice, does not reduce sample sizes, and does not artificially deflate neurocognitive test results or inflate PVT classification accuracy statistics.