PubMed | a Defense and Veterans Brain Injury Center
Type: Journal Article | Journal: Journal of clinical and experimental neuropsychology | Year: 2016
The Mild Brain Injury Atypical Symptoms (mBIAS) scale was developed as a symptom validity test (SVT) for use with patients following mild traumatic brain injury. This study was the first to examine the clinical utility of the mBIAS in a mixed clinical sample presenting to a Department of Veterans Affairs (VA) neuropsychology clinic.Participants were 117 patients with mixed etiologies (85.5% male; age: M = 39.2 years, SD = 11.6) from a VA neuropsychology clinic. Participants were divided into pass/fail groups using two different SVT criteria, based on select validity scales from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2): first, Infrequency Scale (F) scores: (a) MMPI-F-Fail (n = 21) and (b) MMPI-F-Pass (n = 96); and, second, Symptom Validity Scale (FBS) scores: (a) MMPI-FBS-Fail (n = 36) and (b) MMPI-FBS-Pass (n = 81).The mBIAS demonstrated good internal consistency, and each item contributed meaningfully to the total score. At a symptom exaggeration base rate of 35%, an mBIAS cutoff of 11 was optimal for screening symptom exaggeration when groups were classified using both F and FBS scales. This cutoff score resulted in very high specificity (.89 to .94); moderate-high positive predictive power (.71 to .75) and negative predictive power (.72 to .79); and low-moderate sensitivity (.31 to .57). At all base rates of probable somatic exaggeration, a cutoff of 16 resulted in perfect specificity and positive predictive power, but very low sensitivity.The mBIAS has potential for use in samples outside of mild traumatic brain injury. In settings where the symptom exaggeration base rate is 35%, a cutoff of 11 may be used as a red flag for further evaluation, but should not be relied on for clinical decision making. At all base rates of probable somatic exaggeration, psychologists with patients who score 16 can be confident that those patients were exaggerating. Importantly, however, this cutoff may fail to identify a large proportion of patients who are exaggerating.
PubMed | a Defense and Veterans Brain Injury Center
Type: Journal Article | Journal: Journal of clinical and experimental neuropsychology | Year: 2015
The purpose of this study was to examine the clinical utility of two validity scales designed for use with the Neurobehavioral Symptom Inventory (NSI) and the PTSD Checklist-Civilian Version (PCL-C); the Mild Brain Injury Atypical Symptoms Scale (mBIAS) and Validity-10 scale.Participants were 63 U.S. military service members (age: M = 31.9 years, SD = 12.5; 90.5% male) who sustained a mild traumatic brain injury (MTBI) and were prospectively enrolled from Walter Reed National Military Medical Center. Participants were divided into two groups based on the validity scales of the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF): (a) symptom validity test (SVT)-Fail (n = 24) and (b) SVT-Pass (n = 39). Participants were evaluated on average 19.4 months postinjury (SD = 27.6).Participants in the SVT-Fail group had significantly higher scores (p < .05) on the mBIAS (d = 0.85), Validity-10 (d = 1.89), NSI (d = 2.23), and PCL-C (d = 2.47), and the vast majority of the MMPI-2-RF scales (d = 0.69 to d = 2.47). Sensitivity, specificity, and predictive power values were calculated across the range of mBIAS and Validity-10 scores to determine the optimal cutoff to detect symptom exaggeration. For the mBIAS, a cutoff score of 8 was considered optimal, which resulted in low sensitivity (.17), high specificity (1.0), high positive predictive power (1.0), and moderate negative predictive power (.69). For the Validity-10 scale, a cutoff score of 13 was considered optimal, which resulted in moderate-high sensitivity (.63), high specificity (.97), and high positive (.93) and negative predictive power (.83).These findings provide strong support for the use of the Validity-10 as a tool to screen for symptom exaggeration when administering the NSI and PCL-C. The mBIAS, however, was not a reliable tool for this purpose and failed to identify the vast majority of people who exaggerated symptoms.
PubMed | a Defense and Veterans Brain Injury Center and U.S. National Institutes of Health
Type: Journal Article | Journal: Applied neuropsychology. Adult | Year: 2016
This study evaluated the clinical utility of two embedded performance validity tests (PVTs) developed for the Repeatable Battery for the Assessment of Neuropsychological Status: the Effort Index (EI) and the Effort Scale (ES) in mild traumatic brain injury (TBI) patients. Participants were 250 military service members (94.0% male; Age: M=28.4, SD=7.6) evaluated following mild TBI on average 7.4 months (SD=15.6) post-injury. Participants were divided into two groups based on their performance on the Test of Memory Malingering: PVT-Pass, n=193; PVT-Fail, n=57. For the EI, recommended cut-offs for extremely probable, highly probable, and probable poor effort were established. A cut-off score of >3 resulted in low sensitivity (.14), high specificity (.99) and positive predictive power (.94), and moderate negative predictive power (.68) and is recommended for identifying highly probable poor effort. For both the EI and ES, cut-offs for probable poor effort were identified; however, classification accuracy was not much improved relative to simply using the sum of the List Recognition and Digit Span raw scores to classify poor effort. It is acknowledged that the use of a different criterion would likely have resulted in different findings. Nevertheless, findings support the use of the EI and the ES as a red flag for possible poor effort in mild TBI patients, but suggest that, in most cases, additional PVTs would be required to accurately rule poor effort in or out.