S Lippa

Postconcussive symptoms after blast and nonblast-related mild traumatic brain injuries in Afghanistan and Iraq war veterans.

Blast injury is common in current warfare, but little is known about the effects of blast-related mild traumatic brain injury (mTBI). Profile analyses were conducted investigating differences in self-reported postconcussive (PC) symptoms in 339 veteran outpatients with mTBI histories reporting current symptoms based on mechanism of injury (blast only, nonblast only, or both blast and nonblast), number of blast injuries, and distance from the blast. Veterans with any blast-related mTBI history were younger and reported higher posttraumatic stress symptoms than veterans with nonblast-related mTBI histories, with a marginally significant difference in posttraumatic stress symptom report between veterans reporting blast-related mTBI only and those reporting nonblast-related mTBI. The groups did not differ in terms of PC symptom severity or PC symptom cluster profiles. Among veterans with blast-related mTBI histories, PC symptom report did not vary by number of blast-related mTBIs or proximity to blast. Overall, posttraumatic stress symptoms accounted for a substantial portion of variance in PC symptom report. In veteran outpatients with remote mTBI histories who have enduring symptom complaints related to the mTBI, mechanism of injury did not clearly contribute to differential PC symptom severity or PC symptom cluster profile. Proximal rather than distal factors may be important intervention targets in returning symptomatic veterans with mTBI histories.

Clinical utility of the Neurobehavioral Symptom Inventory validity scales to screen for symptom exaggeration following traumatic brain injury.

The purpose of this study was to examine the clinical utility of three recently developed validity scales (Validity-10, NIM5, and LOW6) designed to screen for symptom exaggeration using the Neurobehavioral Symptom Inventory (NSI). Participants were 272 U.S. military service members who sustained a mild, moderate, severe, or penetrating traumatic brain injury (TBI) and who were evaluated by the neuropsychology service at Walter Reed Army Medical Center within 199 weeks post injury. Participants were divided into two groups based on the Negative Impression Management scale of the Personality Assessment Inventory: (a) those who failed symptom validity testing (SVT-fail; n = 27) and (b) those who passed symptom validity testing (SVT-pass; n = 245). Participants in the SVT-fail group had significantly higher scores (p<.001) on the Validity-10, NIM5, LOW6, NSI total, and Personality Assessment Inventory (PAI) clinical scales (range: d = 0.76 to 2.34). Similarly high sensitivity, specificity, positive predictive power (PPP), and negative predictive (NPP) values were found when using all three validity scales to differentiate SVT-fail versus SVT-pass groups. However, the Validity-10 scale consistently had the highest overall values. The optimal cutoff score for the Validity-10 scale to identify possible symptom exaggeration was ≥19 (sensitivity = .59, specificity = .89, PPP = .74, NPP = .80). For the majority of people, these findings provide support for the use of the Validity-10 scale as a screening tool for possible symptom exaggeration. When scores on the Validity-10 exceed the cutoff score, it is recommended that (a) researchers and clinicians do not interpret responses on the NSI, and (b) clinicians follow up with a more detailed evaluation, using well-validated symptom validity measures (e.g., Minnesota Multiphasic Personality Inventory–2 Restructured Form, MMPI–2–RF, validity scales), to seek confirmatory evidence to support an hypothesis of symptom exaggeration.

Clinical utility of embedded performance validity tests on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) following mild traumatic brain injury

ABSTRACT 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.

Female Service Members and Symptom Reporting after Combat and Non-Combat-Related Mild Traumatic Brain Injury

Females are often excluded from military-related mild traumatic brain injury (mTBI) research because of its relatively low prevalence in this population. The purpose of this study was to focus on outcome from mTBI in female service members, compared with males. Participants were 172 United States military service members selected from a larger sample that had sustained an mTBI, and were evaluated within 24 months of injury (Age: mean = 28.9, SD = 8.1) at one of six military medical centers. Eighty-six women were matched to 86 men on nine key variables: TBI severity, mechanism of injury, bodily injury severity, days post-injury, age, number of deployments, theater where wounded, branch of service, and rank. Participants completed the Neurobehavioral Symptom Inventory (NSI) and the Posttraumatic Stress Disorder Checklist (PCL-C). There were no meaningful gender differences across all demographic and injury-related variables (p > 0.05). There were significant group differences and medium effect sizes for the NSI total score and all four NSI cluster scores. Symptoms most affected related to nausea, sensitivity to light, change in taste/smell, change in appetite, fatigue, and poor sleep. There were significant group differences and small-medium effect sizes for the PCL-C total score and two of the three PCL-C cluster scores. Symptoms most affected related to poor concentration, trouble remembering a stressful event, and disturbing memories/thoughts/images. Females consistently experienced more symptoms than males. As females become more active in combat-related deployments, it is critical that future studies place more emphasis on this important military population.

Clinical utility of the mBIAS and NSI validity-10 to detect symptom over-reporting following mild TBI: A multicenter investigation with military service members

ABSTRACT Self-report measures are commonly relied upon in military healthcare environments to assess service members following a mild traumatic brain injury (mTBI). However, such instruments are susceptible to over-reporting and rarely include validity scales. This study evaluated the utility of the mild Brain Injury Atypical Symptoms scale (mBIAS) and the Neurobehavioral Symptom Inventory Validity-10 scale to detect symptom over-reporting. A total of 359 service members with a reported history of mTBI were separated into two symptom reporting groups based on MMPI-2-RF validity scales (i.e., non-over-reporting versus symptom over-reporting). The clinical utility of the mBIAS and Validity-10 as diagnostic indicators and screens of symptom over-reporting were evaluated by calculating sensitivity, specificity, positive test rate, positive predictive power (PPP), and negative predictive power (NPP) values. An mBIAS cut score of ≥10 was optimal as a diagnostic indicator, which resulted in high specificity and PPP; however, sensitivity was low. The utility of the mBIAS as a screening instrument was limited. A Validity-10 cut score of ≥33 was optimal as a diagnostic indicator. This resulted in very high specificity and PPP, but low sensitivity. A Validity-10 cut score of ≥7 was considered optimal as a screener, which resulted in moderate sensitivity, specificity, NPP, but relatively low PPP. Owing to low sensitivity, the current data suggests that both the mBIAS and Validity-10 are insufficient as stand-alone measures of symptom over-reporting. However, Validity-10 scores above the identified cut-off of ≥7should be taken as an indication that further evaluation to rule out symptom over-reporting is necessary.

Performance Validity, Neurocognitive Disorder, and Post-concussion Symptom Reporting in Service Members with a History of Mild Traumatic Brain Injury

Objective To examine the influence of different performance validity test (PVT) cutoffs on neuropsychological performance, post-concussion symptoms, and rates of neurocognitive disorder and postconcussional syndrome following mild traumatic brain injury (MTBI) in active duty service members. Method Participants were 164 service members (Age: M = 28.1 years [SD = 7.3]) evaluated on average 4.1 months (SD = 5.0) following injury. Participants were divided into three mutually exclusive groups using original and alternative cutoff scores on the Test of Memory Malingering (TOMM) and the Effort Index (EI) from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): (a) PVT-Pass, n = 85; (b) Alternative PVT-Fail, n = 53; and (c) Original PVT-Fail, n = 26. Participants also completed the Neurobehavioral Symptom Inventory. Results The PVT-Pass group performed better on cognitive testing and reported fewer symptoms than the two PVT-Fail groups. The Original PVT-Fail group performed more poorly on cognitive testing and reported more symptoms than the Alternative PVT-Fail group. Both PVT-Fail groups were more likely to meet DSM-5 Category A criteria for mild and major neurocognitive disorder and symptom reporting criteria for postconcussional syndrome than the PVT-Pass group. When alternative PVT cutoffs were used instead of original PVT cutoffs, the number of participants with valid data meeting cognitive testing criteria for neurocognitive disorder or postconcussional syndrome decreased dramatically. Conclusion PVT performance is significantly and meaningfully related to overall neuropsychological outcome. By using only original cutoffs, clinicians and researchers may miss people with invalid performances.

Sensitivity and specificity should never be interpreted in isolation without consideration of other clinical utility metrics

Abstract Objective: The purpose of this paper is to highlight the risks and pitfalls of interpreting sensitivity and specificity in isolation when evaluating the clinical utility of a new test/measure to predict a target behavior, disease, or condition. Method: This paper (a) provides a primer for a set of metrics that can be used to appropriately examine the clinical utility of a test/measure (i.e. test operating characteristics – TOC), and (b) provides a discussion regarding various interpretative considerations when using TOCs that supports the tenet of this paper. Conclusions: There are two primary conclusions. First, sensitivity and specificity should never be interpreted in isolation as a means for evaluating the clinical utility of a test/measure. When sensitivity and specificity are used in this manner, more often than not, this will result in erroneous and/or incomplete conclusions regarding the clinical utility of a new test/measure. Second, sensitivity and specificity values are important, but they must be interpreted in conjunction with other more relevant clinical utility metrics (e.g. positive predictive power and negative predictive power).

Utility of the Validity-10 scale across the recovery trajectory following traumatic brain injury.

The Validity-10 scale was recently developed to screen for symptom exaggeration in patients following traumatic brain injury (TBI). However, it has only been validated on patients with TBI largely in the chronic phase of recovery. The influence of time since injury on the Validity-10 scale was investigated in 2,661 male servicemembers with TBI presenting to six U.S. Defense and Veterans Brain Injury Centers. Participants completed the Neurobehavioral Symptom Inventory (NSI). The Validity-10 scale and NSI total score were both weakly statistically significantly (1) positively correlated with time since injury, (2) negatively correlated with bodily injury severity, and (3) higher in participants undergoing medical board evaluations than in participants who returned to duty or were still hospitalized. Participants were statistically more likely to screen positive for possible symptom exaggeration on the Validity-10 scale as time since injury increased. However, the Validity-10 scale was only weakly related to time since injury, TBI severity, bodily injury severity, disposition, age, and return to duty status. That false positives are not increased in the acute phase of recovery and that the Validity-10 scale is not strongly related to clinical factors support the use of the Validity-10 scale in the acute recovery phase and across the TBI recovery trajectory.

The Mild Brain Injury Atypical Symptoms (mBIAS) scale in a mixed clinical sample

ABSTRACT Introduction: 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. Method: 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). Results: 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. Conclusions: 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.

Elevated rates of memory impairment in military service-members and veterans with posttraumatic stress disorder

ABSTRACT Introduction: Studies investigating the neurocognitive effects of posttraumatic stress disorder (PTSD) routinely find “deficits” in various cognitive domains. However, the rate of cognitive impairment in individuals with PTSD remains unclear, as studies have focused on null hypothesis testing (NHT) and inferring patterns of impairment rather than empirically determining the rate of cognitive impairment in this sample. Method: This study examined rates of cognitive impairment using a domain-specific approach in non-treatment-seeking Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn service members and veterans with (n = 92) and without (n = 79) PTSD and without substance abuse/dependence who passed a performance validity measure and were matched on age, education, estimated IQ, and ethnicity. Chi-square analyses were used to compare the rate of cognitive impairment across groups based on normative scores using three cutoffs (−1, −1.5, and −2 SDs). NHT was also used to compare performances across groups. Results: Individuals with PTSD showed higher rates of impairment in memory (−1-SD cutoff) than controls, but equivalent rates of impairment in attention, processing speed, and executive functioning; no significant differences were found on NHT. Impairment in any domain was also more prevalent in PTSD (−1-, −1.5-, and −2-SD cutoffs). No differences were found on NHT or rates of impairment in individuals with PTSD with (n = 34) and without (n = 58) depression. Conclusions: Patients with PTSD were more likely to meet criteria for memory impairment and to show impairment in any domain than controls. Patients with PTSD and comorbid depression were no more likely to be impaired in any cognitive domain or to have lower scores on individual cognitive tasks than patients with PTSD alone. Clinicians noting cognitive impairment in individuals with PTSD should exercise caution before ascribing that impairment to another etiology if deficits are limited to memory.