Detecting malingered pain-related disability with the pain catastrophizing scale: a criterion groups validation study.

Objective: Intentional exaggeration of symptoms is a potential problem in contexts where there are financial incentives to appear disabled. Therefore, calibration of tools to accurately evaluate malingering in these contexts is important. The present study used a criterion groups validation design to determine the ability of the Pain Catastrophizing Scale (PCS) to detect Malingered Pain-Related Disability (MPRD). Method: Individuals meeting inclusionary/exclusionary criteria were selected for this study (n = 219) from a larger dataset of chronic pain patients referred for a psychological evaluation. Patients were classified into malingering groups using the Bianchini, Greve, and Glynn classification system for MPRD. PCS T scores were compared in patients who met MPRD criteria and those who showed no indication of malingering on multiple validity tests. Results: No group differences were observed regarding medicolegal and injury characteristics. Group analyses showed that the Not MPRD group had a significantly lower PCS score (Estimated Marginal Mean [EMM] = 62.3) than all other groups. The Probable and Definite MPRD groups (which together comprise the MPRD group) had the highest PCS T scores (EMM = 77.2 and EMM = 83.8, respectively). A PCS T score of 81 was associated with a 7% false-positive (FP) error rate, sensitivity of 47%, likelihood ratio (LR) of 6.7, and a positive predictive value (PPV) of .74 at base rates around 30%. Conclusions: PCS T scores greater than 81 should raise concerns about the validity of the PCS report and provide additional information that can be helpful in identifying intentional symptom exaggeration in patients with chronic pain.

Classification accuracy of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2)-Restructured form validity scales in detecting malingered pain-related disability.

The symptom reports of individuals with chronic pain are multidimensional (e.g., emotional, cognitive, and somatic) and significantly contribute to increased morbidity and lost work productivity. When pain occurs in the context of a legally compensable event, reliable assessment of a patient's multifactorial symptom experience during psychological or neuropsychological evaluations is a necessity. The Validity Scales of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) have been shown useful in identifying symptom overreporting and feigning within chronic pain samples and a number of studies have emerged supporting the use of the MMPI-2-Restructured Form (MMPI-2-RF) in the detection of simulated or feigned impairment in a variety of populations. To date, only 1 other study exists examining the ability of the MMPI-2-RF to detect exaggerated complaints using a strict operationalization of malingering exclusive to chronic pain samples. The purpose of this study was to examine the classification accuracy of MMPI-2-RF Validity Scales in a group of patients with chronic pain using a criterion-groups design. The final sample consisted of 501 clinical chronic pain patients assigned to groups based on the Bianchini, Greve, and Glynn (2005) criteria for Malingered Pain-Related Disability (MPRD). Results showed that all MMPI-2-RF Validity Scales differentiated malingerers from nonmalingerers with a high degree of accuracy. At cut-offs associated with ≥95% Specificity, Sensitivities ranged from 15% (Fs) to 60% (Response Bias Scale; RBS). This study demonstrates that the MMPI-2-RF Validity Scales are capable of differentiating intentional symptom exaggeration from genuine complaints in a sample of incentivized chronic pain patients. (PsycINFO Database Record

Clusters of financially incentivized chronic pain patients using the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF).

The Minnesota Multiphasic Personality Inventory (MMPI)-2 Restructured Form (MMPI-2-RF) has been shown to have clinical utility in the assessment of individuals with chronic pain (e.g., predicting surgical outcomes). The purpose of this study was to explore the ability of the MMPI-2-RF Validity Scales in profiling patients with chronic pain who had external financial incentive (e.g., workers' compensation claims) and determine the associations between Validity Scale response patterns and important outcomes. Cluster analysis identified 2 similarly sized clusters of patients with very different MMPI-2-RF profiles. Cluster 1 was characterized by valid responding and showed mean elevations on the somatic and low positive emotion Restructured Clinical scales. Cluster 2 was characterized by patients overreporting on the MMPI-2-RF Validity Scales, who also demonstrated elevations on 7 of the 9 RC scales. Cluster membership was differentially associated with clinical variables: patients in Cluster 2 had greater self-reported pain and disability, were less likely to have spine-related findings on imaging and were more likely to be classified as probable or definite malingerers. These results support the utility of the MMPI-2-RF Validity scales in distinguishing between credible and noncredible responses from patients with chronic pain seen within a medico-legal context. (PsycINFO Database Record

Accuracy of the Modified Somatic Perception Questionnaire and Pain Disability Index in the detection of malingered pain-related disability in chronic pain.

The Modified Somatic Perception Questionnaire (MSPQ) and the Pain Disability Index (PDI) are both popular clinical screening instruments in general orthopedic, rheumatologic, and neurosurgical clinics and are useful for identifying pain patients whose physical symptom presentations and disability may be non-organic. Previous studies found both to accurately detect malingered pain presentations; however, the generalizability of these results is not clear. This study used a criterion groups validation design (retrospective cohort of patients with chronic pain, n = 328) with a simulator group (college students, n = 98) to determine the accuracy of the MSPQ and PDI in detecting Malingered Pain Related Disability. Patients were grouped based on independent psychometric evidence of MPRD. Results showed that MSPQ and PDI scores were not associated with objective medical pathology. However, they accurately differentiated Not-MPRD from MPRD cases. Diagnostic statistics associated with a range of scores are presented for application to individual cases. Data from this study can inform the clinical management of chronic pain patients by screening for psychological overlay and malingering, thus alerting clinicians to the possible presence of psychosocial obstacles to effective treatment and triggering further psychological assessment and/or treatment.

Assessment of performance validity in the Stroop Color and Word Test in mild traumatic brain injury patients: a criterion-groups validation design.

The current study assessed performance validity on the Stroop Color and Word Test (Stroop) in mild traumatic brain injury (TBI) using criterion-groups validation. The sample consisted of 77 patients with a reported history of mild TBI. Data from 42 moderate-severe TBI and 75 non-head-injured patients with other clinical diagnoses were also examined. TBI patients were categorized on the basis of Slick, Sherman, and Iverson (1999) criteria for malingered neurocognitive dysfunction (MND). Classification accuracy is reported for three indicators (Word, Color, and Color-Word residual raw scores) from the Stroop across a range of injury severities. With false-positive rates set at approximately 5%, sensitivity was as high as 29%. The clinical implications of these findings are discussed.

The assessment of performance and self-report validity in persons claiming pain-related disability.

One third of all people will experience spinal pain in their lifetime and half of these will experience chronic pain. Pain often occurs in the context of a legally compensable event with back pain being the most common reason for filing a Workers Compensation claim in the United States. When financial incentives to appear disabled exist, malingered pain-related disability is a potential problem. Malingering may take the form of exaggerated physical, emotional, or cognitive symptoms and/or under-performance on measures of cognitive and physical capacity. Essential to the accurate detection of Malingered Pain-related Disability is the understanding that malingering is an act of will, the goal of which is to increase the appearance of disability beyond that which would naturally arise from the injury in question. This paper will review a number of Symptom Validity Tests (SVTs) that have been developed to detect malingering in patients claiming pain-related disability and will conclude with a review of studies showing the diagnostic benefit of combining SVT findings from a comprehensive malingering assessment. The utilization of a variety of tools sensitive to the multiple manifestations of malingering increases the odds of detecting invalid claims while reducing the risk of rejecting a valid claim.

A misleading review of response bias: comment on McGrath, Mitchell, Kim, and Hough (2010).

In the May 2010 issue of Psychological Bulletin, R. E. McGrath, M. Mitchell, B. H. Kim, and L. Hough published an article entitled "Evidence for Response Bias as a Source of Error Variance in Applied Assessment" (pp. 450-470). They argued that response bias indicators used in a variety of settings typically have insufficient data to support such use in everyday clinical practice. Furthermore, they claimed that despite 100 years of research into the use of response bias indicators, "a sufficient justification for [their] use… in applied settings remains elusive" (p. 450). We disagree with McGrath et al.'s conclusions. In fact, we assert that the relevant and voluminous literature that has addressed the issues of response bias substantiates validity of these indicators. In addition, we believe that response bias measures should be used in clinical and research settings on a regular basis. Finally, the empirical evidence for the use of response bias measures is strongest in clinical neuropsychology. We argue that McGrath et al.'s erroneous perspective on response bias measures is a result of 3 errors in their research methodology: (a) inclusion criteria for relevant studies that are too narrow; (b) errors in interpreting results of the empirical research they did include; (c) evidence of a confirmatory bias in selectively citing the literature, as evidence of moderation appears to have been overlooked. Finally, their acknowledging experts in the field who might have highlighted these errors prior to publication may have prevented critiques during the review process.

Memory in traumatic brain injury: the effects of injury severity and effort on the Wechsler Memory Scale-III.

This study examined the effects of traumatic brain injury (TBI) on Wechsler Memory Scale-III (WMS-III) performance. Since poor effort potentially contaminates results, effort was explicitly assessed and controlled using two well-validated cognitive validity indicators, the Portland Digit Recognition Test (PDRT) and Reliable Digit Span (RDS). Participants were 44 mild TBI patients with good effort, 48 mild TBI patients with poor effort, and 40 moderate-severe TBI patients with good effort. A dose-response relationship between injury severity and WMS-III performance was demonstrated. Effect size calculations showed that the good effort mild TBI patients did not differ from normal (average Cohen's d= 0.07) while moderate-severe TBI had a moderate effect on WMS-III scores (average Cohen's d=-0.52). Consistent with previous literature, the moderate-severe TBI group scored the lowest on WMS-III Visual indices. Effort had a larger effect than injury severity on WMS-III scores (average Cohen's d=-1.27). Clinical implications of these findings are discussed.

Classification accuracy of the Millon Clinical Multiaxial Inventory-III modifier indices in the detection of malingering in traumatic brain injury.

The present study used criterion groups validation to determine the ability of the Millon Clinical Multiaxial Inventory-III (MCMI-III) modifier indices to detect malingering in traumatic brain injury (TBI). Patients with TBI who met criteria for malingered neurocognitive dysfunction (MND) were compared to those who showed no indications of malingering. Data were collected from 108 TBI patients referred for neuropsychological evaluation. Base rate (BR) scores were used for MCMI-III modifier indices: Disclosure, Desirability, and Debasement. Malingering classification was based on the Slick, Sherman, and Iverson (1999) criteria for MND. TBI patients were placed in one of three groups: MND (n = 55), not-MND (n = 26), or Indeterminate (n = 26).The not-MND group had lower modifier index scores than the MND group. At scores associated with a 4% false-positive (FP) error rate, sensitivity was 47% for Disclosure, 51% for Desirability, and 55% for Debasement. Examination of joint classification analysis demonstrated 54% sensitivity at cutoffs associated with 0% FP error rate. Results suggested that scores from all MCMI-III modifier indices are useful for identifying intentional symptom exaggeration in TBI. Debasement was the most sensitive of the three indices. Clinical implications are discussed.

Criterion groups validation of the Seashore Rhythm Test and Speech Sounds Perception Test for the detection of malingering in traumatic brain injury.

A criterion-groups validation was used to determine the classification accuracy of the Seashore Rhythm Test (SRT) and Speech Sounds Perception Test (SSPT) in detecting malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI). TBI patients were classified into the following groups: (1) Mild TBI Not-MND (n = 24); (2) Mild TBI MND (n = 27); and (3) Moderate/Severe TBI Not-MND (n = 23). A sample of 90 general clinical patients was utilized for comparison. Results showed that both SRT correct and SSPT errors differentiated malingerers from non-malingerers in the Mild TBI sample. At 96% specificity, sensitivities were 37% for SRT correct and 59% for SSPT errors. Joint classification accuracy showed that the best accuracy was achieved when using a cut-off associated with a 4% false positive error rate in the Mild TBI sample. Specificity was considerably lower in the Moderate/Severe TBI and General Clinical groups. The clinical application of these findings is discussed.

Detection of malingering in mild traumatic brain injury with the Conners' Continuous Performance Test-II.

Classification accuracy for the detection of malingered neurocognitive dysfunction (MND) in mild traumatic brain injury (TBI) is examined for two selected measures from the Conners' Continuous Performance Test-II (CPT-II) using criterion-groups validation. Individual and joint classification accuracies are presented for Omissions and Hit Reaction Time Standard Error across a range of scores comparing mild TBI malingering (n = 27), mild TBI not-malingering (n = 31), and moderate-to-severe (M/S) TBI not-malingering (n = 24) groups. At cutoffs associated with at least 95% specificity in both mild and M/S TBI, sensitivity to MND in mild TBI was 30% for Omissions, 41% for Hit Reaction Time Standard Error, and 44% using both indicators. These results support the use of the CPT-II as a reliable indicator for the detection of malingering in TBI when used as part of a comprehensive diagnostic system.

The Reliable Digit Span test in chronic pain: classification accuracy in detecting malingered pain-related disability.

This study used criterion groups validation (known-groups design) to examine the classification accuracy of the Reliable Digit Span test (RDS) in a large group of chronic pain patients referred for psychological evaluation. The sample consisted of 612 patients classified into one of six groups based on evidence of malingered pain-related disability (MPRD): No-Incentive, Not MPRD; Incentive-Only, Not MPRD; Indeterminate; Possible MPRD; Probable MPRD; Definite MPRD. A total of 30 college student simulators were also included. Lower average RDS scores and higher rates of RDS failure were seen in patients classified as MPRD and in simulators. Consistent with previous literature in a variety of populations, RDS < = 6 provided the most accurate differentiation between MPRD and non-MPRD pain patients. Clinical implications are discussed.

Executive dysfunction in traumatic brain injury: the effects of injury severity and effort on the Wisconsin Card Sorting Test.

This study examined the persistent effects of traumatic brain injury (TBI) on Wisconsin Card Sorting Test (WCST) performance. Since poor effort can contaminate results in populations with incentive to perform poorly, performance validity was explicitly assessed and controlled for using multiple well-validated cognitive malingering indicators. Participants were 109 patients with mild TBI and 67 patients with moderate-to-severe TBI seen for neuropsychological evaluation at least one year post injury. Patients with diffuse neurological impairment and healthy controls were included for comparison. Results suggested a dose-response effect of TBI severity on WCST performance in patients providing good effort; the mild TBI group did not differ from controls while increased levels of impairment were observed in the moderate-to-severe TBI group. Effort during testing had a larger impact on WCST performance than mild or moderate-to-severe TBI. Clinical implications of these findings are discussed.

The Wechsler Adult Intelligence Scale-III and malingering in traumatic brain injury: classification accuracy in known groups.

A known-groups design was used to determine the classification accuracy of Wechsler Adult Intelligence Scale-III (WAIS-III) variables in detecting malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI). TBI patients were classified into the following groups: (a) mild TBI not-MND (n = 26), (b) mild TBI MND (n = 31), and (c) moderate/severe (M/S) TBI not-MND (n = 26). A sample of 80 general clinical patients was used for comparison. Verbal IQ, Verbal Comprehension Index, and Working Memory Index detected approximately 25% of malingerers with a false positive (FP) error rate of approximately 5% in the mild TBI group. Comparable FP rates were obtained in M/S TBI. FP rates for Performance IQ, Perceptual Organization Index, and Processing Speed Index were acceptable in mild TBI but too high in M/S TBI. Previously studied specialized indicators (Vocabulary minus Digit Span and the Mittenberg formula) failed to differentiate malingerers from nonmalingerers. The clinical application of these findings is discussed.

Detecting malingered pain-related disability: classification accuracy of the test of memory malingering.

This study used criterion groups validation to determine the accuracy of the Test of Memory Malingering (TOMM) in detecting malingered pain-related disability (MPRD) across a range of cutoffs in chronic pain patients undergoing psychological evaluation (n = 604). Data from patients with traumatic brain injury (n = 45) and dementia (n = 59) are presented for comparison. TOMM scores decreased and failure rates increased as a function of greater external evidence of intentional under-performance. The TOMM detected from 37.5% to 60.2% of MPRD patients, depending on the cutoff. False positive (FP) error rates ranged from 0% to 5.1%. Accuracy data for Trial 1 are also reported. In chronic pain the original cutoffs produced no FP errors but were associated with high false negative error rates. Higher cutoffs increased sensitivity without adversely affecting specificity. The relevance of these findings to research and clinical practice is discussed.

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.

Detecting malingered pain-related disability: classification accuracy of the Portland Digit Recognition Test.

This study used criterion groups validation to determine the classification accuracy of the Portland Digit Recognition Test (PDRT) at a range of cutting scores in chronic pain patients undergoing psychological evaluation (n = 318), college student simulators (n = 29), and patients with brain damage (n = 120). PDRT scores decreased and failure rates increased as a function of greater independent evidence of intentional underperformance. There were no differences between patients classified as malingering and college student simulators. The PDRT detected from 33% to nearly 60% of malingering chronic pain patients, depending on the cutoff used. False positive error rates ranged from 3% to 6%. Scores higher than the original cutoffs may be interpreted as indicating negative response bias in patients with pain, increasing the usefulness and facilitating the clinical application of the PDRT in the detection of malingering in pain.

Rates of below-chance performance in forced-choice symptom validity tests.

The rates of significantly below-chance results on three neuropsychological symptom validity tests (SVTs) including the Portland Digit Recognition Test (PDRT), Test of Memory Malingering (TOMM), and Word Memory Test (WMT) were compared in a private practice forensic sample of 1032 examinees with alleged mild traumatic brain injury, moderate to severe traumatic brain injury, alleged toxic exposure, and reported chronic pain. The PDRT and WMT were equivalent to one another in the rates of below-chance results, with both yielding more frequent below-chance results than the TOMM. Seemingly more difficult sections of the PDRT and WMT had higher yields than seemingly easier sections. Multiple SVTs were more likely to yield below-chance results than a single test, supporting the use of multiple SVTs in forensic neuropsychological evaluations.

Malingering detection with the Wisconsin Card Sorting Test in mild traumatic brain injury.

This study evaluates the ability of several Wisconsin Card Sorting Test (WCST; Psychological Assessment Resources, 1990) variables to detect malingering in mild traumatic brain injury (TBI). The sample consisted of 373 TBI patients and 766 general clinical patients. Classification accuracy for seven indicators is reported across a range of injury severity and scores levels. Overall, most WCST scores were ineffective in discriminating malingering from non-malingering mild TBI patients. Failure-to-Maintain-Set, the Suhr & Boyer formula, and the King et al. formula detected about 30% of malingerers at cutoffs associated with a false positive error rate of < or =11%. The clinical interpretation and use of these indicators are discussed.

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.