Validity of neuropsychological test results in disability evaluations

Assessment of feigned cognitive impairment in severe traumatic brain injury patients with the Forced-choice Graphics Memory Test

INTRODUCTION

The Forced-choice Graphics Memory Test (FGMT) is a newly developed measure to assess feigned cognitive impairment. This study investigated the ability and reliability of FGMT for identification of malingering in patients with traumatic brain injury (TBI).

METHODS

The FGMT was administered to 40 healthy volunteers instructed to respond validly (Healthy Control, H-C), 40 healthy volunteers instructed to feign cognitive impairment (Healthy Malingering, H-M), 40 severe TBI patients who responded validly (TBI control, TBI-C), and 30 severe TBI patients who evidenced invalid performance (TBI malingering, TBI-M).

RESULTS

Both malingering groups (H-M and TBI-M) performed much more poorly than the nonmalingering groups (H-C and TBI-C). The FGMT overall total score, score on easy items, and score on hard items differed significantly across the four groups. The total score showed the highest classification accuracy in differentiating malingering from nonmalingering. A cutoff of less than 18 (total items) successfully identified 95% of TBI-C and 93.3% of TBI-M participants. The FGMT also demonstrated high test-retest reliability and internal consistency. FGMT scores were not affected by TBI patients' education, gender, age, or intelligence.

CONCLUSION

Our results suggest that the FGMT can be used as a fast and reliable tool for identification of feigned cognitive impairment in patients with TBI.

Portland Digit Recognition Test Performance by Brain Dysfunction Patients without Financial Incentives

The Portland Digit Recognition Test (PDRT) is a neuropsychological measure of motivation. In an extension of previous work, we report PDRT data on 120 patients with brain dysfunction who had no financial incentives for their performance. Percentile distributions, sensitivity and specificity data, and cognitive and demographic correlates are reported. Age, race, and etiology of brain dysfunction (traumatic or nontraumatic) were unrelated to PDRT performance. Education level was significantly related to PDRT scores. Although IQ and verbal memory performance were related to PDRT scores, the PDRT cutoff scores appear valid for brain dysfunction patients with severe cognitive dysfunction.

Malingering in the medical setting

Malingering of mental illness has been studied extensively; however, malingered medical illness has been examined much less avidly. While in theory any ailment can be fabricated or self-induced, pain--including lower back pain, cervical pain, and fibromyalgia--and cognitive deficits associated with mild head trauma or toxic exposure are feigned most frequently, especially in situations where there are financial incentives to malinger. Structured assessments have been developed to help detect both types of malingering; however, in daily practice, the physician should generally suspect malingering when there are tangible incentives and when reported symptoms do not match the physical examination or no organic basis for the physical complaints is found.

Evaluating malingering in contested injury or illness

An interdisciplinary task force of physicians and neuropsychologists with advanced training in impairment and disability assessment provided a review of the literature on malingering in chronic pain, medical disorders, and mental/cognitive disorders. Our review suggests that treating health care providers often do not consider malingering, even in cases of delayed recovery involving work injuries or other personal injuries, where there may be a significant incentive to feign or embellish symptoms or delay recovery. This report discusses the implications of this issue and offers recommendations to evaluating physicians and other health care professionals.

Performance and quality measurement in occupational health services: current status and agenda for further research

BACKGROUND

There is growing interest in evaluating the impact and effectiveness of occupational healthcare services (OHS). Managed care networks, case and disease management, worker health promotion, and utilization review services have proliferated in OHS, usually without scientifically based, objective measures of their impact on the quality of care, outcomes, or costs. Performance and quality improvement (QI) efforts in OHS are different from those in general health care because the population, range of conditions, setting of care, and primary outcomes of interest differ considerably. However, scientific knowledge resulting from the application of QI in general health care can provide a useful framework for the development of measures in OHS.

METHODS

We describe the development, selection, and evaluation of OHS performance and quality measures, and propose a research agenda.

CONCLUSIONS

Quality and performance measures in OHS should address common work-related conditions with high costs, suboptimal outcomes, or unclear parameters for ideal practices. They should reflect stakeholder priorities. Measures should be precise and quantifiable, clearly specified, reliable, valid, and sensitive to important changes. They should be based upon data that can be collected and analyzed at a reasonable cost and effort. The focus of measurement should be on situations where improvement can be achieved by those directly involved in OHS delivery, through defined approaches. Appropriate severity and case-mix adjustment may be especially problematic in OHS. Confidentiality, regulatory concerns, and appropriate use of results must be considered in the development and use of OHS measures. Research is needed to identify, develop, and validate OHS-specific measures, to establish risk adjustment methods, and to test the utility of this information in improving OHS.

The no-fault flavor of disability syndromes

There are many controversial disability syndromes, representing medicolegal and social dilemmas for a variety of medical disciplines. Health care professionals are at a loss to cure these patients, and judges and disability review boards struggle to be fair while at the same time trying to understand the basis and appropriateness of the ever-growing claims of disability. We review these disability syndromes, examining the basis for their existence, their mechanism, and how these patients can better be understood in a constructive and helpful manner. In doing so, we emphasize the sick role, illness behavior, secondary and tertiary gain, and somatization.

Neuropsychological Assessment of Suspected Malingering: Research Results, Evaluation Techniques, and Further Directions of Research and Application

Possibilities for neuropsychological assessment of suspected malingering are addressed. First, various forms of deception (malingering, factitious disorders, hysteria) and their implications for clinical neuropsychology are discussed. Then, threshold models for the detection of malingering as well as specially designed assessment techniques (e. g., individual tests, deficit testing, tests specifically for malingerers, and symptom validity testing) are described. Finally, the current status of clinical methods and research strategies is summarized, and recent and further developments of assessment and research are reported.

Memory performance after head injury: contributions of malingering, litigation status, psychological factors, and medication use

Impaired memory test performance can reflect a host of factors, such as head injury/postconcussive syndrome, involvement in litigation, malingering behavior, psychological distress, and medication use. Such factors are important in interpreting memory test performances in patients referred in the context of litigation. We examined memory test performance in mild head-injured patients in litigation, mild to moderate head-injured patients not in litigation, severely head-injured patients not in litigation, depressed patients, and patients with somatization disorders. Findings showed that several memory tests were useful in distinguishing probable malingerers from the other groups. There was a complex interaction among malingering status, psychological status, and medication use in the prediction of memory test results. Although nonneurological factors were related to memory impairment, litigation status alone was not predictive of memory performance. The results emphasize the need to consider nonneurological factors in the interpretation of poor memory performance in patients seen for forensic evaluation.

Amsterdam Short-Term Memory test: a new procedure for the detection of feigned memory deficits

The validity of two malingering tests, the newly developed Amsterdam Short-Term Memory (ASTM) test and the Distraction test (Baker, Hanley, Jackson, Kimmance, & Slade, 1993) was examined in a group of patients with closed-head injury (CHI), a normal control group, and a control group with instruction to feign memory deficits. Both control groups consisted of first-degree relatives of the patients. The ASTM test is a forced-choice verbal memory test, based on the technique of symptom validity testing. Stimulus material was chosen from category norms and chance level is not transparent. The CHI and normal control groups scored near ceiling on the ASTM test, whereas the feigned deficit group scored significantly worse. The ASTM test classified all subjects correctly. Contrary to expectation, the Distraction test appeared to be invalid. The score profiles of the CHI and feigning groups on conventional memory and concentration tests were indistinguishable from each other. Thus, the ASTM test may be very useful for the detection of malingering and other kinds of less than optimal performance. The test may readily be constructed in any language for which category norms are available.

Order effects in the administration of a forced-choice procedure for detection of malingering in disability claimants' evaluations

100 disability claimants of the Social Security Administration referred for neuropsychological evaluation and 40 undergraduate college students asked to simulate brain damage were administered a measure for the detection of malingering, an abbreviated version of the Hiscock Forced-choice Procedure, and other neuropsychological tests. Half of each group was administered the Hiscock Procedure at the beginning of the battery; the other half was administered this test last. For both groups, the results indicated poorer performance on the earlier administration of the abbreviated Hiscock Forced-choice Procedure. Formal measures for detection of malingering should be an integral and early part of any neuropsychological evaluation in which the subject has a financial incentive to perform poorly.

Detecting the malingering of cognitive deficits: an update

There has recently been a dramatic increase of empirical studies that investigate methods for detecting malingering of cognitive deficits. The present review focuses on a comparison of simulated and suspected malingerers in the malingering literature, and critiques the numerous approaches to the detection of malingering. The approaches that are reviewed include detection of floor effects, discrepancies of information, response bias, neuropsychological tests and batteries, symptom validity testing, and anomalous performance on memory tests. The latter approach has only recently been proposed by researchers and may show the most promise.