On the diagnosis of malingered pain-related disability: lessons from cognitive malingering research

Prevalence of malingering in patients with chronic pain referred for psychologic evaluation in a medico-legal context

OBJECTIVE

To provide an empirical estimate of the prevalence of malingered disability in patients with chronic pain who have financial incentive to appear disabled.

DESIGN

Retrospective review of cases.

SETTING

A private neuropsychologic clinic in a southeastern metropolitan area.

PARTICIPANTS

Consecutive patients (N=508) referred for psychologic evaluation related to chronic pain over a 10-year period (1995-2005).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Prevalence of malingering was examined using 2 published clinical diagnostic systems (Malingered Pain-Related Disability and Malingered Neurocognitive Dysfunction) as well as statistical estimates based on well validated indicators of malingering.

RESULTS

The prevalence of malingering in patients with chronic pain with financial incentive is between 20% and 50% depending on the diagnostic system used and the statistical model's underlying assumptions. Some factors associated with the medico-legal context such as the jurisdiction of a workers' compensation claim or attorney representation were associated with slightly higher malingering rates.

CONCLUSIONS

Malingering is present in a sizable minority of patients with pain seen for potentially compensable injuries. However, not all excess pain-related disability is a result of malingering. It is important not to diagnose malingering reflexively on the basis of limited or unreliable findings. A diagnosis of malingering should be explicitly based on a formal diagnostic system.

Disability evaluation of the pain : the present and prospect in Korea

OBJECTIVE

Pain has long been regarded as a subjective symptom. Recently, however, some regard a type of intractable chronic pain as a disease. Furthermore, chronic persistent pain becomes a cause of permanent impairment (PI). In 6th edition, the American Medical Association (AMA) Guides has rated the pain as a PI. In Korea, pain has been already been rated as a PI. Here, we examined the present status and the prospect of disability evaluation for the pain in Korea.

METHODS

Pain can be rated as a PI by the Workmen's Compensation Insurance Act (WCIA) and Patriots and Veterans Welfare Corporation Act (PVWCA) in Korea. We examined the definition, diagnostic criteria and grades of the pain related disability (PRD) in these two acts. We also examined legal judgments, which were made in 2005 for patients with severe pain. We also compared the acts and the judgments to the criteria of the 6th AMA Guides.

RESULTS

The PRD can be rated as one of the 4 grades according to the WCIA. The provisions of the law do not limit the pain only for the complex regional pain syndrome (CRPS). The PRD can be rated as one of the 3 grades by the PVWCA. If there were objective signs such as osteoporosis, joint contracture and muscle atrophy corresponding to the CRPS, the grade is rated as 6. When the pain always interferes with one's job except easy work, the grade is rated as high as 5. In Korea, judicial precedents dealt the pain as a permanent disability in 2005.

CONCLUSION

Although there were no objective criteria for evaluation of the PRD, pain has been already rated as a PI by the laws or judicial precedents, in Korea. Thus, we should regulate the Korean criteria of PRD like the AMA 6th edition. We also should develop the objective tools for evaluation of the PRD near in future.

Interviews for the assessment of long-term incapacity for work: a study on adherence to protocols and principles

Background

Assessments for long-term incapacity for work are performed by Social Insurance Physicians (SIPs) who rely on interviews with claimants as an important part of the process. These interviews are susceptible to bias. In the Netherlands three protocols have been developed to conduct these interviews. These protocols are expert- and practice-based. We studied to what extent these protocols are adhered to by practitioners.

Methods

We compared the protocols with one another and with the ICF and the biopsychosocial approach. The protocols describe semi-structured interviews with comparable but not identical topics. All protocols prescribe that the client's opinion on his capacity for work, and his arguments, need to be determined and assessed. We developed a questionnaire to elicit the adherence SIPs have to the protocols, their underlying principles and topics. We conducted a survey among one hundred fifty-five experienced SIPs in the Netherlands.

Results

Ninety-eight SIPs responded (64%). All respondents used some form of protocol, either one of the published protocols or their own mix. We found no significant relation between training and the use of a particular protocol. Ninety percent use a semi-structured interview. Ninety-five percent recognise having to verify what the claimant says and eighty-three percent feel the need to establish a good relation (p = 0.019). Twelve topics are basically always addressed by over eighty percent of the respondents. The claimant's opinion of being fit for his own work or other work, and his claim of incapacity and his health arguments for that claim, reach a hundred percent. Description of claimants' previous work reaches ninety-nine percent.

Conclusion

Our study shows professional consensus among experienced Dutch SIPs about the principle of assessment on arguments, the principle of conducting a semi-structured interview and the most crucial interview topics. This consensus can be used to further develop a protocol for interviewing in the assessment of incapacity for work in social insurance. Such a protocol can improve the quality of the assessments in terms of transparency and reproducibility, as well as by enabling clients to better prepare themselves for the assessments.

Are the Original and Second Edition of the California Verbal Learning Test Equally Accurate in Detecting Malingering?

This two-part study sought to determine the equivalence of the California Verbal Learning Tests (CVLT-1 and CVLT-2) in the detection of malingering in traumatic brain injury (TBI) and chronic pain. Part 1 compared a variety of scores from the two versions in carefully matched patient groups. Part 2 used criterion groups (known-groups) methodology to examine the relative rates of false positive (FP) errors across the two versions. Participants were 442 TBI (CVLT-1 = 310; CVLT-2 = 132) and 378 chronic pain patients (CVLT-1 = 250; CVLT-2 = 128). Overall, the CVLT-2 was more difficult than the CVLT-1, with the chronic pain patients showing larger version effects than the TBI patients. The two versions of the CVLT were equally accurate in detecting malingering in TBI and chronic pain. However, they were not interchangeable. The use of CVLT-1 cutoffs with the CVLT-2 may result in an increased risk of FP error. Appropriate cutoff adjustment in clinical practice is recommended.

The relationship between the modified somatic perception questionnaire and dynamic platform posturography

OBJECTIVE

To analyze if patients whose vestibular symptoms are associated with nonorganic sway patterns show more evidence of somatization and/or malingering than patients whose vestibular symptoms are associated with normal or physiologically abnormal sway patterns observed in people with documented vestibular pathologic findings.

PATIENTS

One hundred fifteen patients with complaints of vestibular dysfunction and hearing impairment.

INTERVENTIONS

Computerized dynamic posturography (CDP) and completion of the Modified Somatic Perception Questionnaire (MSPQ)--a validated test for the detection of malingering.

MAIN OUTCOME MEASURES

Computerized dynamic posturography results classified into 4 categories (normal, physiologic abnormal, borderline-aphysiologic, and aphysiologic) were correlated with the results of the MSPQ.

RESULTS

A significant CDP group effect on the MSPQ, with the aphysiologic patients scoring significantly higher than the other groups. Moreover, a significantly higher proportion of aphysiologic patients scored more than the MSPQ cutoffs for malingering.

CONCLUSION

Results indicate that patients who have aphysiologic CDP sway patterns are more likely to have higher MSPQ scores. Both aphysiologic CDP results and high MSPQ scores have been associated with intentional exaggeration. These results indicate that patients with both aphysiologic CDP findings and high MSPQ scores are more likely to be intentionally exaggerating their balance-related complaints and deficits.

Classification Accuracy of MMPI-2 Validity Scales in the Detection of Pain-Related Malingering

The purpose of this study was to determine the accuracy of Minnesota Multiphasic Personality Inventory 2nd edition (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) validity indicators in the detection of malingering in clinical patients with chronic pain using a hybrid clinical-known groups/simulator design. The sample consisted of patients without financial incentive ( n = 23), nonmalingering patients with financial incentive ( n = 34), patients definitively determined to be malingering based on published criteria ( n = 32), and college students asked to simulate pain-related disability ( n = 26). The MMPI-2 validity scales differentiated malingerers from nonmalingerers with a high degree of accuracy. Hypochondriasis and Hysteria were also effective. For all variables except Scale L, more extreme scores were associated with higher specificity. This study demonstrates that the MMPI-2 is capable of differentiating intentional exaggeration from the effects on symptom report of chronic pain, genuine psychological disturbance, and concurrent stress associated with pursuing a claim in a medico-legal context.

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.

The Booklet Category Test and Malingering in Traumatic Brain Injury: Classification Accuracy in Known Groups

A known-groups design was used to determine the classification accuracy of 12 Booklet Category Test variables in the detection of malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI). Participants were 206 TBI and 60 general clinical patients seen for neuropsychological evaluation. Slick, Sherman, and Iverson's (1999) criteria were used to classify the TBI patients into non-malingering, suspect, and MND groups. Classification accuracy of the BCT depended on the specific variable and injury severity examined, with some scores detecting more than 40% of malingerers with false positive error rates of 10% or less. However, the BCT variables are often influenced by cognitive ability as well as malingering, so caution is indicated in applying the BCT to the diagnosis of malingering. Application of these data in clinical practice is discussed.

Pain, Malingering, and Performance on the WAIS-III Processing Speed Index

Pain patients often report cognitive symptoms and many will include them in their claims of disability. The Processing Speed Index (PSI) of the WAIS-III was investigated as one aspect of cognitive functioning in six groups. Slight impairment was found for PSI and Digit Symbol subtest performance, but not for Symbol Search, in a Laboratory-induced Pain group and a Clinical Pain group. The lowest scores were found in a Simulator group instructed to fake cognitive impairment and a Clinical Pain group diagnosed as Malingering. Results suggest that PSI scores are only slightly reduced by laboratory-induced pain or chronic pain, and that unexpectedly low scores in the absence of significant/documented brain dysfunction suggest poor effort or deliberate misrepresentation.

The prevalence of cognitive malingering in persons reporting exposure to occupational and environmental substances

OBJECTIVE

Directly estimate the prevalence of cognitive malingering in persons claiming exposure to occupational and environmental substances.

METHODS

Retrospective review of 128 neuropsychological cases with financial incentive. Estimates were based on two methods: (1) clinical identification using the Slick, Sherman and Iverson criteria for malingered neurocognitive dysfunction (MND), and (2) statistical modeling based on patient performance on several individual psychometric indicators of malingering.

RESULTS

The prevalence based on the clinical method was 40%. The statistically based estimates ranged from 30% to more than 45% depending on model parameters. Different incentive parameters may influence prevalence.

CONCLUSIONS

Cognitive malingering in toxic exposure is common and must be adequately addressed in the clinical neuropsychological assessment of toxic exposure and in research on its neurocognitive effects or findings will likely over-estimate the degree of cognitive impairment and related disability.

Compensation and Malingering in Traumatic Brain Injury: A Dose-Response Relationship?

The purpose of this study was to determine if there is a dose-response relationship between potential monetary compensation and failure on psychological indicators of malingering in traumatic brain injury. 332 traumatic brain injury patients were divided into three groups based on incentive to perform poorly on neuropsychological testing: no incentive; limited incentive as provided by State law; high incentive as provided by Federal law. The rate of failure on five well-validated malingering indicators across these groups was examined. Cases handled under Federal workers compensation laws showed considerably higher rates of failure and diagnosable malingering than cases handled under State law. The findings indicate that monetary compensation associated with workers compensation claims is a major motive for exaggeration and malingering of problems attributed to work-related brain injuries. The clinician's index of suspicion regarding exaggeration and malingering of symptoms and deficits should be much higher in the context of Federal workers compensation claims, particularly in patients who have suffered only mild traumatic brain injury.

Ethical Issues Associated With the Assessment of Exaggeration, Poor Effort, and Malingering

The use of effort tests is standard practice in forensic neuropsychology. There is a tremendous amount of good information available in test manuals and the research literature regarding the proper and responsible use of these tests. However, it is clear that there are numerous ethical issues and considerations associated with the assessment of exaggeration, poor effort, and malingering. Many of these issues are discussed, and recommendations are provided.

Pain, malingering and the WAIS-III Working Memory Index

BACKGROUND CONTEXT

Pain patients often report cognitive symptoms, and many will include them in their claims of disability. There is empirical evidence that patients with pain do experience problems on attention-demanding cognitive tasks, but the results are mixed and the potential impact of exaggeration in the context of pain-related litigation has not been addressed.

PURPOSE

1) Examine the impact of pain and malingering on attention; 2) determine if the Working Memory Index (WMI) of the Wechsler Adult Intelligence Scale-3 (WAIS-III) can reliably detect malingering.

STUDY DESIGN/SETTING

Study 1: simulator design; Study 2: clinical known-groups design.

PATIENT SAMPLE

Study 1 used healthy college students; Study 2 used chronic pain patients and neurological patients.

OUTCOME MEASURES

The WMI and its constituent subtests.

METHODS

Study 1: College students were administered the WMI under three conditions: standard administration, with cold-pressor induced pain, or with instructions to simulate impairment due to pain. Study 2: Known-groups design in which the WMI was examined in non-malingering and definite malingering chronic pain patients, non-malingering moderate-severe traumatic brain injury, and memory disorder patients seen for routine psychological evaluation. Malingering was operationalized using published criteria.

RESULTS

There were no group differences in WMI or its subtests among non-malingering groups, but some individual clinical patients with pain did score at a level suggestive of attentional impairment. The lowest scores were found in the simulated malingering college students and definite malingering clinical pain groups, in which about half scored worse than 95% of the non-malingering clinical patients.

CONCLUSIONS

This study demonstrated that even when controlling for exaggeration some pain patients do exhibit problems with attentional function. However, significant impairment in WMI performance (eg, index score<or=70), particularly in the absence of brain dysfunction, cannot reasonably be attributed to the effects of either acute or chronic pain, even at moderate to severe levels, and likely reflects intentional exaggeration.