QME ASSESSMENT OF MALINGERING IN CHRONIC PAIN
by William W. Deardorff, Ph.D, ABPP.
Course content © Copyright 2010 - 2013 by William W. Deardorff, Ph.D, ABPP. All rights reserved.
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IMPORTANT NOTE: This course is approved for California Qualified Medical Evaluator (QME) continuing education credits as well as other accreditations held by BehavioralHealthCE.com. If you do not need California QME continuing education credits, you should take Chronic Pain and Malingering. This course addresses information specific to practicing as a QME in the State of California. In My Account, be sure to add QME to your Degree list and your QME Provider Number to your Licenses. All Degrees and Licenses will be printed on the CE certificate.
A Brief History of Malingering
Why Assess for Malingering?
Malingering, ACOEM, and AMA Impairment Guides
Reasons for Lack of Malingering Assessment
Undetected/Underestimated Physical Illness
Factitious Disorder with Physical Symptoms
Myths about Malingering
Refined Definitions of Malingering
Base Rates of Malingering
Malingered Pain Related Disability
Physical and Medical Evaluation Data
The Physical Examination
Other Physical Measures
Cognitive Symptoms and Neuropsychological Testing
Veracity of the Data and Conclusions
Evaluation of Malingered Pain: A Proposed Method
Summary and Conclusions
• List 4 reasons for the lack of malingering assessment
• Explain the differential diagnosis of malingering
• Discuss the adaptational model of malingering
• List 5 myths related to malingering
• Explain Malingered Pain-Related Disability (MRPD)
A Brief History of Malingering
Dorland’s Medical Dictionary defines malingering as “the willful, deliberate, and fraudulent feigning or exaggeration of the symptoms of illness or injury, done for the purposes of a consciously desired end.” The word “malingerer” was first introduced in Grove’s Dictionary of the Vulgar Tongue in 1785. The word “malingerer” was likely derived from the French word “malingre”, which means sickly or feeble. This term was originally used in a military setting to describe individuals who pretended to be sick in order to evade military duty. Although the term is of relatively recent origin, the simulation of illness to avoid military duty dates at least to the ancients Greek and was punishable by death. It is recorded in writings from the second century that Roman conscripts would cut off their fingers to avoid military duty (Galen, “On Feigned Diseases and the Detection of Them”). With the advent of the workers compensation systems during the late 1800’s, and tort law related to personal injury in the 1900’s, interest in malingering increased dramatically. Until that time, the concept was related only to avoiding military service. The classification of malingering is contained in both the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) and the International Classification of Diseases (ICD-10). In both cases, “malingering” is not a diagnosed condition but rather is in “other classes” or “other conditions.”
Why Assess For Malingering
In many situations, a patient’s level of impairment will directly relate to such things as access to certain medical treatments, financial compensation, and disability status. Evaluation of impairment can be a critical factor in personal injury civil cases, workers’ compensation injuries, social security disability determinations, long term disability insurance benefits, among other things. In all of these situations, the patient is certainly invested, to a greater or lesser degree, in the outcome, and this is directly impacted by the impairment determination.
Healthcare practitioners are often called upon to make various impairment determinations. This includes such things as Independent Medical Evaluations (IME), Qualified Medical Evaluations (QME), Agreed Medical Evaluations (
Given these objectives, it is extremely important that the evaluator develop conclusions that are based on accurate information and scientific evidence. One component of these types of evaluations includes determining a patient’s level of credibility and assessing for the possibility of malingering. This is important due to the fact that much of the data upon which the evaluator’s decisions will be based is self-report information provided by the patient. If credibility is not established, the veracity of the self-report information cannot be completely determined.
The importance of specifically assessing a patient’s credibility is addressed in the ACOEM (2004) Guidelines especially when evaluating a chronic pain syndrome. The Guidelines discuss certain circumstances that may predispose an examinee to symptom magnification, somatization, or malingering when chronic pain syndromes are being assessed (see pages 134-135). In addition, the issue of assessing for malingering when evaluating chronic pain within a medical-legal context is addressed numerous times in the Guides to the Evaluation of Permanent Impairment (AMA Impairment Guides, 2000). Although the importance of evaluating a patient’s credibility and assessing for malingering is discussed in various places throughout the AMA Guides, it is specifically mentioned many time in the chapter on Chronic Pain as can be seen in Table 2. Even so, in routine practice, formal assessment for malingering may not occur that often.
Reasons for Lack of Malingering Assessment
As can be seen, both the AMA and ACOEM Guidelines suggest that malingering must be considered by the evaluator when assessing chronic pain. However, it does not appear that assessment for patient credibility occurs frequently except within most significant medical-legal contexts. This may be due to many reasons:
Malingering is a diagnosis of exclusion. A wide range of diagnoses must be ruled out prior to the classification of malingering (Resnick et al., 2008). As discussed in this course, malingering is most often a diagnosis or classification of exclusion. When a clinician is confronted with inconsistencies that suggest malingering, all other possible diagnoses must generally be ruled out including the somatoform disorders, an unexplained physical illness, or symptom exaggeration due to a chronic pain syndrome. Of course, this can be an onerous task and in many cases it is simply easier to ignore the possibility of malingering.
False belief that malingering rarely occurs. The practitioner evaluating the chronic pain patient may believe that the base rate of malingering is extremely low and therefore, if all patients are accepted as credible, the false-negative rate is low anyway. As we will discuss in more detail throughout this course, early studies of chronic pain did suggest that the base rate of malingering was very low (1-10%). However, a series of more recent and better controlled studies have demonstrated a much higher base rate of malingering amongst the chronic pain patient population evaluated in medical-legal settings (20-40%).
Lack of tools to assess malingering. Another reason for the low rate of assessing credibility in a chronic pain patient population may be a perceived lack of “tools” available to the examiner to assess malingering. The purpose of this course is to review those various techniques and provide the practitioner with additional skills related to detection of malingering.
False belief that malingering requires significant financial incentive. Examiners may believe that malingering is only likely when a patient has a very significant financial incentive to engage in such deceptive behavior. However, this is not the case. For instance, one study demonstrated that 82% of disabled people in the United States were financially worse off than when they were working, 17% had little change, and only 1.5% were better off (Nagi and Hadley, 1972). As discussed by Aronoff et al. (2007), that trend had not changed by the 1990’s and “few people on disability benefits are better off than when they were working” (p. 180). Other studies have demonstrated that half of disabled persons receiving compensation benefits receive less than 50% of their prior net earnings, and only one in eight receives more than 80%. In addition, only 5% of persons with back pain were financially better off than when they were working. These 5% tended to be individuals who were generally part-time or very poorly paid workers who had very little financial incentive to work at all. As discussed by Aronoff et al. (2007), the overall social picture suggests that the vast majority of people on disability are much worse off financially than when they were working. As such, the data suggest that malingering in chronic pain occurs 20-40% of the time, yet it is clearly not always related to improved income status (disability payments) or the possibility of a large financial windfall at settlement.
These statistics will not come as any surprise to those who routinely complete impairment and disability evaluations. However, as Aronoff et al. (2007) point out, “the amount of compensation benefits is only one factor in maintaining an ongoing sick role” (p. 181). As the authors discuss, there are a number of other socio-economic factors that can support the sick role and explain some level of malingering including work demands and environment, job dissatisfaction, lack of advancement and career potential, job availability, among other things. Other factors associated with various levels of malingering include such things as obtaining medications, receiving other secondary benefits (e.g. being approved for Social Security Disability Income also allows one the availability of Medicare medical coverage), and removing the patient from a stressful work situation. In summary, there are a number of factors beyond financial compensation that can explain some level of malingering in a chronic pain patient population.
The nature of categorical classification. Evaluators may be reluctant to formally address the issue of malingering because of how the diagnostic classification system has been structured. As we will discuss in more detail, malingering is specifically outlined in the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV-TR, 2000). In the DSM, a strict classification system is used and a patient is either categorized as a malingerer or not. There is no allowance for any gradation of malingering such as the concept of “partial malingering” as discussed in the ACOEM Practice Guidelines and elsewhere (Resnick, 1997, 2000). As we will discuss, this is one of the significant criticisms of the DSM-IV Malingering classification and likely causes practitioners to be reluctant to label a patient as a “malingerer.” Even if some level of malingering is suspected along with some level of an actual impairment, there is essentially no means to officially document these results.
Consequence to evaluator and patient for misclassification. A misclassification of malingering may inappropriately label the patient and cause a stigmatization that results in an inability to get appropriate medical treatment or other benefits (e.g. disability). Many practitioners simply do not want to take the risk that this might occur even when faced with overwhelming evidence for malingering. Also, the clinician may fear retaliation from the patient either through the legal system, through reports to various ethics and professional boards, or even a more aggressive fashion. Again, evaluators may be inclined to simply avoid these “hassles” by not addressing the malingering issue.
The DSM-IV-TR (2000) describes malingering as “intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives such as avoiding military duty, avoiding work, obtaining financial compensation, evading criminal prosecution, or obtaining drugs” (p. 739). The DSM-IV-TR goes on to state that “under some circumstances, malingering may represent adaptive behavior--for example, feigning illness while a captive of the enemy during wartime.” The DSM-IV-TR provides four criteria for meeting the definition and these can be seen in Table 3.
According to the DSM-IV-TR, probable malingering exists when two or more of the four criteria are met. The DSM-IV-TR classifies malingering as a “V” code indicating “Other Conditions That May be the Focus of Clinical Attention.” In this nomenclature, malingering is not considered to be a mental disorder.
There are essentially six conditions from which Malingering must be differentiated and these include the following: Undetected or underestimated physical illness; the Somatoform Disorders (somatization, conversion, hypochondriasis, pain); and Factitious Disorder With Predominantly Physical Signs and Symptoms.
Undetected or Underestimated Physical Illness
In the vast majority of malingering cases the diagnosis is largely based on the exclusion of other factors that might account for the findings. Aside from the infrequent dramatic situations in which irrefutable evidence of malingering is available (e.g. the patient who is claiming some type of paresis is observed using the body part in a fully functioning manner), all other factors must be ruled out. One of the most critical factors to rule out is some type of undetected or underestimated physical illness that might explain the symptoms, impairment, and level of disability. Patients who present with unexplained somatic complaints may actually have an illness that has not yet been detected through evaluation and testing. This might even be true when the presentation of symptoms is fairly dramatic. Research in the area of social and cultural factors in illness behavior have demonstrated that these influences can greatly affect how a patient displays symptoms such as pain behaviors. For instance, in some cultures, pain behaviors tend to be displayed more dramatically while other groups ascribe to a more stoic presentation of symptoms related to the same condition. Therefore, the evaluator should never be quick to suggest malingering just based on the fact that the display of illness behaviors tends to be rather dramatic. In all cases, the evaluator must reasonably determine that all appropriate medical testing has been completed given the symptoms that are under evaluation. At that point, and prior to heading down a path of more esoteric physical diagnostic possibilities, the patient’s credibility and possibility of malingering should be evaluated.
The somatoform disorders that must be differentiated from malingering include somatization disorder, conversion disorder, hypochondriasis, and pain disorder. As discussed in the DSM-IV-TR “the common feature of the somatoform disorders is the presence of physical symptoms that suggest a general medical condition (hence, the term somatoform) and are not fully explained by a general medical condition, by the direct effects of a substance, or by mental disorder (e.g. Panic Disorder).” In contrast to Factitious Disorders and Malingering, the symptoms are not under voluntary (conscious) control. Somatoform Disorders are conceptualized as having a predominantly psychological etiology.
Somatization disorder. An essential feature of a somatization disorder is a pattern of recurring, multiple, clinically significant somatic complaints. These myriad of physical complaints begin before age 30 years and over a period of several years. These complaints result in treatment being sought or significant impairment in social, occupational, or other important areas of functioning. These symptoms occur across multiple organ systems and, after appropriate investigation, each of the symptoms cannot be fully explained by a known general medical condition or the direct effects of a substance. These symptoms are not intentionally produced or feigned.
Conversion Disorder. The essential feature of a conversion disorder is the presence of symptoms or deficits affecting voluntary motor or sensory function that suggest a neurological or other general medical condition. Psychological factors are judged to be associated with this symptom or deficit. The symptoms are not intentionally produced or feigned. The symptom or deficit cannot, after appropriate investigation, be fully explained by a general medical condition, or by the direct effects of a substance, or as a culturally sanctioned behavior or experience.
Hypochondrias. The essential feature of hypochondriasis is preoccupation with fears of having, or the idea that one has, a serious disease based on a misrepresentation of one or more bodily signs or symptoms. A thorough medical evaluation does not identify a general medical condition that accounts for the patient’s concerns about disease or symptoms. The preoccupation persists despite appropriate medical evaluation and reassurance. The preoccupation is not intentional and is not better accounted for by some other psychological disorder (e.g. generalized anxiety, obsessive-compulsive disorder, etc.).
Pain Disorder. The essential feature of a pain disorder is pain that is the predominant focus of the clinical presentation and is of sufficient severity to warrant clinical attention. The pain disorder can be associated with psychological factors if these are judged to have the major role in onset, severity, exacerbation, or maintenance of the pain. The pain disorder can be associated with both psychological factors and a general medical condition when both psychological factors and medical issues are judged to have important roles in the pain. Lastly, the pain disorder only associated with a general medical condition is “not considered a mental disorder.” In this case, the pain results from a general medical condition and psychological factors are judged to play either no role or a minimal role in its onset or maintenance. As with the other differential diagnostic categories, the elicitation of pain behaviors is judged to be primarily non-intentional and not influenced by conscious factors.
Factitious Disorder With Predominantly Physical Signs and Symptoms.
Factitious disorders have their own classification section and are not Somatoform Disorders. Factitious disorders are more characterized by physical or psychological symptoms that are intentionally produced or feigned in order to assume the sick role. The presentation may include fabrication of subjective complaints (e.g. complaints of acute abdominal pain in the absence of such pain), self-inflicted conditions (e.g. production of abscesses by injection of saliva into the skin), exaggeration or exacerbation of preexisting general medical conditions (e.g. feigning of a grand mal seizure by an individual with previous history of seizure disorder), or any combination or variation of these. The only motivation for the intentional production of these symptoms is to assume the sick role. External incentives for the behaviors such as economic gain, or avoiding legal responsibility, are absent.
Differentiation of the various somatoform disorders and malingering can be found in Table 4. In Table 4, conscious and unconscious might also be equated with intentional and unintentional (or some reinforcement paradigm for those behaviorists in the group).
Critique of The DSM-IV Malingering Classification System
As reviewed previously, the DSM-IV-TR provides four guidelines for when to suspect malingering. According to the DSM-IV-TR, probable malingering exists when two or more of the four criteria are met. Critics have generally leveled two criticisms of this system: (1) the classification system is too broad and (2) it is based on a “criminological” model of malingering.
Many experts consider the DSM-IV definition of malingering as being too overly broad and inclusive. This leads to the risk of over-identification of patients as malingerers and a high level of false-positives. As we discussed previously, this may be one reason for an evaluator’s reluctance to classify a patient as a “malingerer” at least according to the DSM-IV-TR definition. As noted by Rogers (1990; 2008), the use of these criteria for detecting malingering (two out of the four criteria) leads to an impressively high correct classification of approximately two-thirds of true malingerers. However, Rogers also determined that the strategy leads to an over-classification of true psychiatric patients as malingerers. Rogers concluded that persons meeting two of the four DSM-IV-TR criteria have only a one in five chance of being true malingerers (20%). Of course, an 80% false-positive rate is extremely high and unacceptable, especially given the enormity of the consequences that generally follow a patient when classified as a malingerer.
The second criticism of the DSM-IV definition of malingering is that it follows a “criminological” model. The basic premise of the criminological model is that malingering is typically an antisocial act that is likely to be committed by antisocial persons (Rogers, 2008).
Models of Malingering
Rogers (2008) describes three models of malingering to explain the underlying motivation of the individual who engages in this behavior. These models include the criminological model, the pathogenic model, and the adaptational model.
Criminological model. As briefly discussed previously, the criminological model of malingering describes the primary motivation for the behavior as typically “an antisocial act that is likely to be committed by antisocial persons,” (Rogers, 2008, p. 9). Rogers discusses that this model, especially as characterized in the DSM-IV, is overly moralistic and empirically lacking. As discussed by Rogers (2008), “the fundamental problem with the criminological model is that it relies on common rather than distinguishing characteristics of malingering” (p. 9). He argues that this model is not able to distinguish characteristics of malingerers and is certainly not applicable to the vast majority of individuals engaging in deceptive behavior.
Pathogenic model. The pathogenic model conceptualizes an underlying psychological disorder as motivating the presentation of malingered symptoms. In the pathogenic model, the production of symptoms is thought to be an effort to gain control over real symptoms. As the patient’s condition deteriorates, he or she presumably becomes less able to control the feigned disorders and symptoms and they become replaced with real ones. In this model, the malingerer’s motivation is based on true psychopathology. Although the feigned symptoms are initially conscious and purposeful, the deterioration and replacement process is unconscious. The pathogenic model no longer receives general support and is not representative of most malingerers (Rogers, 2008).
Adaptational model. The adaptational model was developed by Rogers and suggests that the motivation to malinger can be understood within the context of a cost-benefit analysis done by the individual of his or her options. As discussed by Rogers (2008) “in what is described as the adaptational model, malingerers attempt to engage in a cost-benefit analysis in choosing to feign psychological impairment” (p. 9). In this model, malingering may be more likely under three circumstances:
(1) When the context is adversarial,
(2) When the personal stakes are high, and
(3) When there are no viable alternatives.
As discussed by Hamilton et al. (2008), the advantage of this type of adaptational model is that it allows the clinician to ask important questions beyond those specified by the DSM-IV-TR. This is illustrated by the hypothetical case example.
Applying a DSM-IV-TR type of categorical analysis to these patients might leave the evaluator to conclude that each of them is a malingerer and not appropriate for any type of treatment. On the other hand, using the adaptational model, one can assess the adverse nature of the situation, how high the personal stakes are for the individual, and if there actually exists any viable alternative to the behavior. Using an adaptational model of analysis, each of these four individuals would be conceptualized quite differently. Although all of the behavior may fall under the rubric of malingering and being deceptive, the case formulations would be quite different.
Myths About Malingering
In Rogers (2008) comprehensive book, Clinical Assessment of Malingering and Deception, Third Edition, he lists common misconceptions of malingering. He states that these myths are held by both practitioners and the public. The common myths as discussed by Rogers (2008, pages 7-8) as well as others, are as follows.
Malingering is very rare. As we discussed previously in this course, it seems that many evaluators simply ignore the possibility of malingering believing that it is quite infrequent and essentially inconsequential. As we will discuss subsequently, the rate of malingering is not infrequent and is much higher than previously determined. As discussed by Rogers (p. 7) “when the outcome of an evaluation has important consequences, malingering should be systematically evaluated. Its neglect is a serious omission.”
Malingering is a static response style. This is the belief that “once a malingerer, always a malingerer.” As discussed by Rogers, most efforts at malingering appear to be related to specific objectives in a particular context. This analysis fits with the Adaptational Model as well as the case example of the person presenting to the emergency room with complaints of low back pain. In any of those situations, if the work factors had not existed, the malingering would likely not have occurred.
Deception is evidence of malingering. Rogers believes that this fallacy is based on the erroneous notion that “malingerers lie; therefore, liars malinger.” For instance, patients may engage in some deception for a number of reasons, none of which relate to malingering (external incentives). One of the most common occurrences may be the withholding of certain information due to such things as embarrassment or other reasons. The practitioner would be mistaken to conclude that simply because a patient does not share certain information, it is automatically indicative of malingering.
Malingering precludes genuine disorders. This myth is based on the assumption that malingering and genuine disorders are mutually exclusive. This often occurs when a practitioner initially accepts all symptoms as genuine and then, after determining malingering, rejects all of the symptoms as being feigned. In reality, the vast majority of cases in which chronic pain malingering is determined, the patient will have a mixture of “real” and fabricated symptoms.
Malingering is an antisocial act by an antisocial person. As Rogers (2008) discusses, this common misperception is perpetuated by the DSM-IV. In this myth, the practitioner is confusing “common characteristics” (many antisocials are malingerers) with “discriminating characteristics” which demonstrates that the presence of antisocial personality disorder does not discriminate malingerers from non-malingerers.
Malingering is similar to the iceberg phenomenon. This myth is based on the misconception that any evidence of malingering is sufficient for its classification. As such, any observable evidence of feigning or deception (similar to the visible tip of the iceberg) indicates a pervasive pattern of malingering that is yet unseen or undetermined.
Malingering has stable base rates. Rogers (2008; See for a review) has demonstrated marked variations in the base rates for malingering across forensic settings. The researchers go on to state that even within the same setting, marked variations are likely to occur depending on the referral question and individual circumstances. The variation in malingering is impacted by such things as the level of motivation of the patient and the sophistication of the malingering detection tools.
Malingering is easily detectable by practitioners. Rogers (2008) makes the point that practitioners believe that malingerers frequently engage in an indiscriminate effort that is easily detectable by the evaluator. In fact, it is more common that the influence of the previously reviewed myths leads practitioners to believe that malingering is not only infrequent, but also easily detected when it occurs. If an evaluator is of this opinion, the chances of actually detecting malingering are quite small.
Malingering is driven by financial incentives only. Although not empirically tested, most evaluators may be of the opinion that malingering is only potentially present if significant financial incentives exist. As discussed previously, the vast majority of cases in workers’ compensation, Social Security Disability, and long term disability systems, do not involve financial incentives that even come close to what the patient may have been producing when working full-time. Even so, research and surveys certainly demonstrate that malingering occurs within these disability systems at a rate that is not negligible (This data will be reviewed subsequently). Therefore, other non-financial incentives are influencing the emergence of malingering and deceptive behavior. If the practitioner blanketly assumes that significant financial incentives are necessary for malingering, the deceptive behavior will be missed essentially 100% of the time.
Refined Definitions of Malingering
As discussed previously, the DSM-IV criteria for malingering is not operationally defined and results in a very high false-positive rate. In addition, the DSM-IV forces the clinician to conceptualize malingering in a categorical fashion especially relative to cases involving excessive illness behavior. As discussed by Hamilton et al. (2008) one of the greatest disadvantages of this type of categorical thinking and classification is the fact that these strict distinctions do not relate to excessive illness (pain) behavior. For instance, as we have seen in previous examples, displays of excess pain behavior can be due to a number of factors many of which do not qualify as malingering in the spirit of the DSM-IV definition. Based upon these problems with categorical classification of malingering (the patient is either a malingerer or he/she is not) the adaptational model of Rogers was developed. Consistent with this model, there are other conceptualizations of how malingering can be best described and these are presented by Resnick et al. (1997, 2008) and Rogers (1997). Resnick discussed that malingering can be further categorized into the following categories: (1) Pure malingering, (2) Partial malingering, and (3) False imputation (See Table 5).
Rogers (1997) also argues for “gradations of malingering and defensiveness” consistent with his adaptational model (p. 13). This is presented in Table 6. The adaptational model of malingering, along with these additional concepts provided by Resnick, provides the practitioner with a process for more accurately describing malingering or deceptive behavior. These methods go far beyond the simple black and white categorization forced by the DSM-IV classification.
The Challenge Of Detecting Pain Malingering
Much of the research on malingering has been done by neuropsychologists over the past two decades. This extensive body of literature has focused on the detection of malingered cognitive deficits within the context of brain injury. More recently, investigation of methods to identify malingered pain have increased. However, the complexity of pain and its associated symptoms brings with it special problems when attempting to detect malingering and deception.
As discussed by Bianchini et al. (2005), “the pathophysiology and psychological factors underlying pain-related disability are complex individually and in combination, and an understanding of both is important in the clinical management of the pain patient” (p. 405). These complexities are outlined in the Chronic Pain Management Courses (Introduction to Chronic Pain Management; QME Pain Concepts). In the course, it is discussed that the perception of pain, level of suffering, and expression of pain behaviors are influenced by multiple physical and non-physical factors. To the extent that non-physical influences are present, pain behaviors and level of suffering may be demonstrated beyond what would be expected due to nociceptive input and objective findings (e.g. tissue damage). In fact, this type of “symptom amplification” is characteristic of almost any chronic pain syndrome even when there is no element of malingering (even partial malingering). Consider the following chronic pain patient example:
Any evaluator who has assessed a chronic pain patient, especially within a medical-legal context, has likely seen more than his or her share of this type of patient. The question is, “does this cluster of symptom presentation and behavior represent malingering or not?” This type of patient is conceivably demonstrating a fully developed chronic pain syndrome, significant somatization disorder, or some other reasonable condition that does not represent malingering. On the other hand, a patient with the exact same presentation might be engaged in a very high level of malingering and deceptive behavior. As discussed by Bianchini et al. (2005), those patients with excess disability could reasonably be divided into two groups: (1) those whose excess disability is related to unconscious psychological factors (e.g. somatization), and (2) those whose excess disability is a result of some level of intentional fabrication or exaggeration.
Since the presentations of a chronic pain syndrome in the non-malingerer and malingerer are so similar, detection can be extremely difficult. In addition, as discussed by McDermott and Feldman (2007), it is also relatively easy to malinger pain because everyone has had the experience of pain and knows how it should appear to others. The authors discuss that the malingerer’s pain complaints will vary according to the medical sophistication of the patient but, the malingerer often knows the characteristics of the pain associated with the condition that he or she is feigning (or exaggerating). The ubiquitous availability of high quality medical information on the internet, along with various blogs and information-sharing services, have certainly made malingering of pain easier for the motivated person.
Base Rates of Malingered Pain
Estimates of the base rate of malingered disability in patients with chronic pain who have a financial incentive to appear disabled are important for at least two reasons:
(1) To help evaluators make informed decisions regarding individual clinical or forensic cases
(2) To help assess the diagnostic accuracy of clinical indicators or malingering.
By having knowledge of the base rate of malingered pain, evaluations can be improved relative to diagnostic accuracy. For instance, assuming a base rate of malingered pain is 1% will cause an evaluator to approach the assessment process in a much different fashion than an assumed base rate of 40%.
In one of the first review of studies done in the area of chronic pain malingering, Fishbain et al. (1999) reviewed 328 studies related to malingering, disease simulation, dissimulation, symptom magnification syndrome, and submaximal effort. Of the references identified, 68 studies related to the topic of pain. The 68 studies were divided into 12 topic areas including such things as existence of malingering within the chronic pain setting, identification of malingering by questionnaire, identification of submaximal effort, etc. Each study was rated for scientific quality according to accepted guidelines and the conclusions were based on the results of those ratings. Fishbain et al. (1999) concluded that the reviewed studies indicated that malingering and dissimulation do occur within the chronic pain setting. The authors determined that the rate may be between 1.25% and 10.4%. The authors felt that due to the poor quality of the vast majority of studies, the prevalence percentages were not reliable. These authors also concluded that malingering could not be reliably identified by facial expression testing, questionnaire, sensory testing, or clinical examination.
The conclusions of the Fishbain et al. (1999) review of malingering research have been criticized on multiple methodological grounds. For instance, it has been argued that the studies reviewed and cited to support the low malingering base rate did not appropriately address the question of malingering prevalence. These studies often failed to determine the incentive status of the patients and were sometimes irrelevant to chronic pain (see Greve et al., 2009a for a review). The critique goes on to state that some of the studies reviewed by Fishbain et al. (1999) were “simply misrepresented” (Greve et al., 2009a). The authors critiquing the early work stated that some of the studies were actually examinations of patients with head injuries rather than chronic pain. In addition, the critics state that even some of the statistics were erroneous leading to an incorrect lower range of 1.25% when it should actually have been 23.5% (see Greve, 2009a for a review of these issues). The critics of this early work concluded that Fishbain’s actual range of estimated malingering prevalence should have been from about 10% to 24%, rather than 1% to 10%. Greve et al. (2009a) conclude that “in short, given the multitude of problems with the data, the Fishbain findings should not be considered a scientifically valid estimate for the prevalence of malingering in chronic pain” (p. 1118).
Subsequent studies have suggested a prevalence rate of malingered chronic pain of between 20% and 40%. Consistent with this data, a nationwide survey of Americans completed in the 1990’s found that 20% felt it was acceptable for an individual to engage in purposeful misrepresentation of claims in the compensation system (Insurance Research Council, 1992, 1993). This data suggests that there is a cultural milieu amongst a certain percentage of Americans that feel some level of malingering is acceptable. More recent research has attempted to identify the base rates of chronic pain malingering in several ways including surveys of practitioners and direct evaluation of malingering.
Survey of Practitioners
Mittenberg et al. (2002) obtained comprehensive surveys from 144 neuropsychologists across the United States and Canada who were involved in the medical-legal evaluation of injured patients. Respondents to the survey had been in practice an average of 18.5 years and interpreted an average of 21.3 neuropsychological examinations per month. Prevalence estimates were therefore based on 33,531 annual cases involved in personal injury, disability, criminal, or medical matters. Across a number of categories, the practitioners were asked to estimate the percentage of their litigating or compensation-seeking cases that engaged in probable symptom exaggeration or malingering. Results demonstrated that reported base rates were significantly related to the proportion of plaintiff versus defense referrals. Not surprisingly, patients referred by defense attorneys or insurers had higher rates of probable malingering and exaggeration. To control for these effects, prevalence estimates were statistically adjusted to account for the referral source. The adjusted survey data demonstrated that base rates for probable malingering or symptom exaggeration was 38.6% in fibromyalgia or chronic fatigue and 33.5% in pain or somatoform disorders. The authors concluded that “these estimates correspond with the rates that have been previously reported in empirical studies that used objective diagnostic methods and are representative of those observed in a variety of practice settings” (p. 1097).
Direct assessment of malingering. In a comprehensive retrospective study, Greve et al. (2009a) sought to estimate directly the base rate of malingering in patients with chronic pain through careful examination of archival case files. In this study, data were obtained from the files of 508 individuals referred for psychological evaluation related to chronic pain over a ten year period. All of the patients had financial incentives, usually in the form of a workers’ compensation claim or personal injury lawsuit. The study used two methodologically distinct, but somewhat overlapping approaches to estimate malingering rates: (1) clinical diagnosis using published diagnostic systems and (2) statistical estimation based on psychometric test performance. In this study, the extensive clinical and testing data from 508 consecutive referrals was analyzed. The evaluation data for each patient was quite comprehensive including such things as a review of the medical records, a clinical interview, and an extensive battery of neuropsychological testing including symptom validity tests. As discussed by the authors, indicators of malingering used in the study could be divided into three types related to assessment method:
(1) Stand-alone-forced-choice symptom validity tests that appear to assess memory, but really assess whether adequate effort to perform well was provided. These tests include the Portland Digit Recognition Test (PDRT), the Test of Memory Malingering (TOMM), and the Word Memory Tests (
(2) Internal or embedded indicators derived from standard tests of cognitive ability. Again, it is beyond the scope of this course to review all of these various tests, but they have been found to discriminate between malingerers and non-malingerers.
(3) Psychological measures of symptom exaggeration and over-reporting derived from the MMPI-2. For a more detailed review of the MMPI-2 and chronic pain assessment, please refer to the course MMPI-2 and Chronic Pain.
Classification of malingering was determined using two diagnostic systems. The first system was developed by Slick et al. (1999) and is designed to identify malingered neurocognitive dysfunction (
The general findings of the study are summarized in Table 9. These prevalence rates were validated using the second method of statistical estimation. It is beyond the scope of this course to discuss all of the detailed analyses that were completed in this study and the reader is referred to the original source for further detailed information. The final prevalence of malingering of between 20-50% as discussed by the authors below is based upon both methods of analyses, much of which is not presented here (hence only the rate of 36% is seen in Table 9). The authors concluded that:
“The present study presents estimates of the prevalence of malingering in patients with chronic pain referred for psychologic evaluation. Previously published estimates of malingering rates in chronic pain have suffered from a variety of methodologic and conceptual limitations. This study is the first to use explicit operationalization of malingering and data from direct assessment of patients to estimate malingering prevalence in patients with chronic pain. The results of this study suggest that the prevalence of malingering in patients with pain with financial incentive is between 20% and 50%, depending on specific methods and assessment context. The rates of malingering observed in this study are consistent with methodologically sound survey results and are generally in line with the findings from other clinical conditions. Having a workers’ compensation claim, especially in a federal jurisdiction, and being represented by an attorney are associated with slightly higher rates of malingering. Overall, these results emphasize the fact that malingering is present in a sizeable minority of patients with pain seen for potentially compensable injuries” (Greve et al., 2009a, p. 1124).
Malingered Pain Related Disability (MPRD)
The detection and diagnosis of malingered cognitive impairment is a problem that has been addressed by clinical neuropsychology over the past couple of decades. This issue is more recently being addressed relative to the malingering of chronic pain. However, the complexities of evaluating a chronic pain patient make determination of malingering exceptionally challenging. Bianchini et al. (2005) suggest that many of the lessons learned from the detection of cognitive malingering using neuropsychological approaches might also be applied to the chronic pain issue. The authors cite four general areas that are important to the study of Malingered Pain Related Disability (MPRD):
Any research on malingering requires that it is clearly operationalized and that malingering groups can be defined on the basis of external criteria derived from a systematic analysis and integration of multiple sources of clinical information encompassing behavior in multiple domains. This idea is borrowing from the criteria for diagnosis of malingered neurocognitive dysfunction as developed by Slick et al. (1999). As demonstrated in Table 7, the Slick classification system includes four criteria (A-D), each of which has been operationalized. After determining results for each of the criteria, malingered neurocognitive dysfunction is classified as definite, probable, or possible. As discussed by Bianchini et al. (2005) the Slick criteria would have to be adapted to encompass all of the behavioral domains in which pain related disability is manifested.
Empirical data concerning the accuracy of detection techniques are essential for their ongoing development, clinical application, and admissibility in legal proceedings. Relevant indices of the classification system accuracy, including sensitivity, specificity, and predictive value, must be clearly stated. This has been an area of significant shortcoming in previous studies of malingered pain.
Classification accuracy depends on the detection of malingering (sensitivity), specificity (identifying those not malingering), and positive predictive value, are critical. Positive predictive value is the degree of confidence that a given score correctly indicates the presence of a condition (e.g. malingering) and depends most on specificity. Specificity measures the proportion of negatives which are correctly identified (e.g. the percentage of healthy people who are identified as not having the condition). Sensitivity is the degree to which a test or classification system correctly identifies the condition in question. In other words, it measures the proportion of actual positives which are correctly identified as such (e.g. the percentage of sick people who are identified as having the condition). Since false-positives in the detection of malingering are highly undesirable, the goal is to maximize specificity. As the authors discuss “practically, it is better to detect some malingerers with few false-positives than to try to achieve the impossible goal of complete discrimination of groups” (Bianchini et al., 2005, p. 406).
The accurate assessments of sensitivity and specificity require accurate group assignment. In any research related to a malingering test or indicator, there must be at least two criterion samples: A suspected malingering sample (index) and a non-malingering (control) group.
Given this conceptual basis as established in the neuropsychological research detecting malingering of neurocognitive dysfunction, Bianchini et al. (2005) outline a model of classifying malingered pain related disability (MPRD). Since pain patients may report symptoms across a variety of dimensions (physical complaints, emotional symptoms, cognitive problems), any or all of these symptom-groups may be important relative to the disability claim in litigation. The relevant question is not only “how much pain is this person experiencing” but “to what degree is this person disabled by their pain?” (Bianchini et al., 2005, p. 407). Or in greater detail, “the question is whether the nature and severity of disability attributed to the injury is inconsistent with what would be expected given the physical parameters of the injury” (p. 407).
The first task (consistent with criterion A of the MPRD system, Table 8) is establishing evidence of significant external incentives. A diagnosis of MPRD requires evidence of external incentive and intentional symptom production. Incentive is usually easily identified, but determination of intent is a more difficult task. As discussed, at the heart of the issue of malingering is the question, “Is the patient intentionally performing below their true capacity or manifesting more disability/symptoms than is actually the case?” (p. 407). Intent, as inferred from the facts of the case and patterns of inconsistency, is one of the central concepts in the diagnosis of malingering. The concept includes the notion that if someone is malingering, it is harder to do so consistently relative to someone who is simply manifesting their true symptoms (physical, psychological, or cognitive). Therefore, malingering is established by detecting inconsistencies across and within multiple dimensions. This includes an analysis of inconsistencies within each dimension (e.g. behavior over time or across different evaluations), between dimensions (e.g. physical versus psychological), and relative to what is known about normal and abnormal function. From what is known about malingering, the more inconsistencies that are present and the greater the magnitude, the more the likelihood that the patient is deliberately attempting to misrepresent his or her true capabilities or symptomatology.
Multiple sources of evaluation data are taken into account in the MPRD Classification System (Bianchini et al., 2005) to assess Criteria A through E. This data includes evidence from: physical and medical findings, psychological and neuropsychological testing, and from self-report. In each of these categories, the results are generally determined to fall on a range from no findings to definitive evidence. Most definitive evidence is based on “compelling inconsistencies” in which the patient demonstrates one set of symptoms when he or she is aware of being evaluated versus another set of symptoms (or lack thereof) when the person is unaware that evaluation is occurring. Although inconsistencies occur in chronic pain patients who are not malingering, definitive evidence for malingering is determined when there are “compelling” inconsistencies across and within a number of domains.
Physical and Medical Evaluation Data
Chronic pain patients most often undergo frequent physical examinations and diagnostic tests long before they are ever evaluated for cognitive and/or emotional factors. This is likely due to two reasons: First, patients will undergo appropriate physical examination in the acute stages of the pain. During this time, the cognitive and emotional aspects of a chronic pain syndrome have yet to develop. Second, significant physical issues that may be causing the chronic pain (e.g. a tumor, systemic disorder) must be ruled out prior to more comprehensive evaluation and treatment of a benign chronic pain syndrome. Even in a fully developed chronic pain syndrome in which significant tissue pathology explaining the nociceptive input has been ruled out, the physical examination and evaluation of the chronic pain patient is generally the initial starting point. The following is from Bianchini et al. (2005) as well as other sources cited throughout this course.
The Physical Examination.
There are no objective laboratory tests that allow examiners to independently quantify pain without the use of a patient’s self-report and observation of pain behaviors (e.g. grimacing, verbalizations, gait, etc.). Patients may intentionally exaggerate physical problems in at least two ways: (1) exaggerated physical symptom complaints and (2) diminished physical capacity. Many physical examination maneuvers have been developed in an attempt to identify “non-organic” causes of symptoms (see Greer et al., 2005, for a review). These physical examination techniques are designed to detect either symptom exaggeration and/or malingering. Similar to the neuropsychological test being used to detect cognitive malingering, the patient is unaware that the physical examination maneuver is actually testing for symptom exaggeration rather than a true medical finding. Examples of some of these physical maneuvers, and the symptoms they are designed to assess, can be found in Table 10. Probably the most famous of these physical examinations for non-organic signs is the Waddell Signs. The Waddell Examination includes five categories.
Dr. Waddell initially developed the “Waddell Signs” in order to “identify back pain patients who require more detailed psychological assessment” (Waddell et al., 1980). The Waddell Examination was designed to assess the possible contribution of psychological factors to the patient’s presentation of pain behaviors. The Waddell Signs were never intended as a test of malingering and this is a common mistake made by practitioners. In fact, in a comprehensive review of 60 studies of Waddell Signs published between 1980 and 2000, Fishbain et al. (2004) found that there was consistent evidence that Waddell Signs are associated with poor treatment outcomes, but not associated with secondary gain and could not discriminate organic from non-organic problems. The authors concluded that there was no evidence for an association between the results of the Waddell physical evaluation and secondary gain or malingering.
The remainder of the physical maneuvers in Table 10 have no support in scientific study. In the Mankopf’s Test, it is assumed that actual pain will increase heart rate. This test has only been investigated in a small study comparing 20 low back pain patients considered “non-organic” and 20 pain-free controls. A mechanical pain stimulus was applied to the subjects’ fingers and there was no significant difference in heart rate response between the two groups. There was also no significant effect of pain on heart rate in either group. Furthermore, there is no published research relative to McBride’s test. Other examination techniques which have no basis in science but have almost taken on a clinical lore include such things as checking shoes for uneven wear in patients limping into the office; manual laborers claiming inability to work, but having calluses, dirt or lacerations on their hands; and, patients who do not injure themselves upon fainting or collapsing.
Overall, there is no physical examination maneuver that has been found to reliably identify and discriminate malingerers from non-malingerers. Unfortunately, some of these techniques (e.g. Waddell Signs) are frequently used for the purpose of identifying malingering even though this was not the intention of the examination and has no empirical support. Given these lack of findings, what is the physician evaluator to do? There is still a vast amount of data available to the evaluating physician that can be used to complete an initial determination of the possibility of malingering to be targeted for further assessment. Some indicators of possible malingering can be found in Table 11. These are reviewed in more detailed subsequently and the evaluator should be aware of these issues while completing the evaluation.
Another element of the medical examination might include direct behavioral observation. In this case, data can be collected from within the context of the medical appointment as well as from other sources. For instance, the physician might take note of the patient’s behavior when he or she is not aware of being observed, behavioral presentation symptoms, changes in behavior depending upon those present (e.g. increased pain behavior with spouse in attendance), among other things.
Another type of observation is surveillance tapes. If available, these should be carefully reviewed by the evaluating physician (and other evaluators). The question is, “Are the surveillance findings consistent or inconsistent with the injury, diagnostic test findings, patient’s reported level of impairment, physical examination results, and all other sources of information?” Of course, surveillance findings are usually only a small sample of an individual’s 24 hour day. Therefore, higher levels of functioning seen on surveillance evidence might be explained in many ways (some accurate, and some not). In my experience, these include such things as the patient reporting s/he was on significant pain medication to allow for the increased functioning, it was a “good” day, it was just a brief time period, etc. All of these may or may not be legitimate reasons for the findings and preclude malingering. However, the issue is to assess whether the information suggests a “compelling inconsistency” and then begin to compare the findings with other domains of information.
Another aspect of the physical and medical evaluation will be correlated with actual diagnostic study results (e.g. MRI, CT, EMG, etc.). The assessment of chronic pain is difficult because, in many cases, there are no specific tests or laboratory findings. Or, “abnormal” findings may have absolutely no meaning at all. For instance, as discussed in the spine surgery screening courses (Spine Surgery Screening, QME-Spine Surgery Screening), after the age of 40 years old, the incidence of bulging disc or other “abnormalities” is seen in 50 percent or more of MRI scans in individuals without symptoms. Other complex chronic pain problems that are difficult to assess with diagnostic tests include fibromyalgia (FM), complex regional pain syndrome (CRPS), among others.
In my experience, the careful review of the medical records can be one of the most valuable sources of information. In completing the record review, one is looking for such things as:
Has any other doctor suggested malingering or exceptional symptom exaggeration?
Are the records consistent with the patient’s self-report? (e.g. mechanism of injury, response to treatment)
Has the patient shown any response to any treatment?
Did the patient’s presentation change at some point apparently not related to the expected course of the disorder? (e.g. hiring an attorney, being “fired” from a job that was being held, psychosocial stress, etc.).
Other Physical Measures
Aside from the physical examination, there are other physical measures that have been used in an effort to detect malingering. One example is the Functional Capacity Evaluation. A Functional Capacity Evaluation (FCE) is a comprehensive battery of performance based tests that is commonly used to determine ability for work, activities of daily living, or leisure activities. Depending on the referral question, the FCE evaluator will have the patient engage in a number of physical activities including such things as lifting, pushing, pulling, squatting, overhead activities, endurance activities, etc. A typical FCE may last several hours up to a couple of days depending on the scope of the testing. Various questionnaires and pain ratings are also used as part of the assessment. Since functional capacity is influenced by psychosocial as well as physical factors, it is often difficult to determine whether maximal effort is exerted in FCE’s. The sensitivity and specificity of a number of tests included in the FCE have been investigated. In general, the research has demonstrated unacceptable levels of sensitivity (those giving maximal effort may be incorrectly labeled as exerting submaximal effort). Therefore, caution has been urged relative to labeling patients as malingering based on FCE results. In addition, a number of studies examining the ability of evaluators to determine when maximal or submaximal effort was exerted all reached similar conclusions--that evaluators must use extreme caution when determining the level of effort to ensure that injured clients are not incorrectly labeled.
Evaluation of Emotional Symptoms
Psychological symptoms are often one of the consequences of a physical injury and development of the chronic pain syndrome. The psychological symptoms of a chronic pain syndrome are most often assessed through clinical interview and psychological testing. The MMPI-2 is the most widely used psychological test for chronic pain patients. The MMPI-2 validity scales show promising results relative to distinguishing between non-malingerers, symptom amplification without malingering, and malingering. Other psychological assessments that also include methods or assessing exaggeration of emotional symptoms include the Personality Assessment Inventory (PAI), Millon Clinical Multiaxial Inventory-III (MCMI-
MMPI-2. In an attempt to identify exaggeration or malingering of physical symptoms, the gold standard is the MMPI-2. The MMPI-2, and its predecessor the MMPI, have been used in the assessment of chronic pain patients for over 40 years. For a detailed discussion of the MMPI-2, in evaluating chronic pain patients, please refer to the course, Chronic Pain and The MMPI-2. Recently, Bianchini et al. (2008) completed a study of the classification of MMPI-2 validity scales in the detection of pain-related malingering using a “known groups” design. The known groups design “employs persons in actual clinical or applied settings that have been independently identified by mental health professionals as engaging in dissimulation. These persons are then compared to criterion groups of persons known as (or assumed to be) honest responders (Rogers, 1997, p. 16). In a later publication, Rogers (2008) describes the method further: Known groups comparisons are composed of two discreet and independent phases: (1) establishment of criterion groups (e.g., bonified patients and malingerers) and (2) systemic analysis of similarities and dissimilarities between criterion groups (p. 423). Rogers goes on to state that because of the difficulty of utilizing a known group’s design (e.g. external identification of malingerer), it is rarely used. In the Bianichini et al. (2008) study, patients were identified as definite MPRD clinical pain patients by external criteria and compared with other groups relative to the MMPI-2 Validity Scales.
The patients were obtained from archival records of approximately 200 cases who had undergone psychological pain evaluation. Extensive data was available for each patient including medical records, objective medical diagnostic test results, physician’s clinical diagnoses, as well as neuropsychological test results. Patients whose malingering status could not be reliably determined from the data available were dropped from the study. The patients were divided into the following groups:
No incentive, not malingering: These patients had pain attributable to spine related pathology and were not seen in a financially compensable context. In addition, none of these patients had any documented evidence of drug abuse or drug seeking behavior. Therefore, external incentives were ruled out.
Incentive only, not malingering: This group included patients with financial incentive (e.g. workers’ compensation claim, personal injury litigation) who showed no evidence of non-credible cognitive or physical dysfunction. These patients demonstrated no abnormalities on the Neuropsychological Symptom Validity Tests. In addition, any patients that demonstrated any evidence of non-organic findings on medical examination, inconsistencies between self-report and documented records, abnormal pain behavior, or questionable validity on formal functional capacity evaluation, were excluded. Lastly, all of the patients in this group had objective clinical evidence of spinal pathology either by history of spine surgery or abnormal findings on imaging studies.
Definite MPRD clinical pain patients. These patients met the Bianchini et al. (2005) criteria for definite MPRD by virtue of statistically below chance performance on at least one of the forced choice
Simulators. College students were asked to complete the MMPI-2 based on instructions requiring them to respond as if they were experiencing severe, persistent, and chronic pain, but “faking” their impairment in a way that is believable because “if your faking is detected, your lawsuit will be thrown out of court and you will get nothing.”
Although a number of psychological test results were available for the patients, only the MMPI-2 results will be discussed currently. A summary of the mean MMPI-2 scores for each of the research groups can be found in Table 12 (See MMPI-2 and Chronic Pain for a detailed review of the scales). Although many more MMPI-2 Validity Indices were evaluated, only those that were found to significantly differentiate the groups are presented in this summary Table. As can be seen, for the four validity measures of F, Fb, Fp, and MI there are no significant differences between the no-incentive group and incentive-only (not malingering) groups. However, there are significant differences between these two groups and the definite MPRD and student simulator groups. Therefore, these validity scales successfully discriminated between non-malingerers (no-incentive, incentive-only) and malingerers (definite MPRD, student simulators).
As discussed by Bianchini et al. (2008), the use of these measures must go beyond simply determining that there are group differences between non-malingerers (as groups). This involves the classification accuracy of these validity scales relative to sensitivity and false-positive error rate (FP rate). Sensitivity is the true positive or hit rate for a test. In this study, sensitivity reflects the number of malingerers who had a positive test result at a given cut-off divided by all malingerers. The FP rate reflects the proportion of non-malingerers whose scores fell in the malingering range, according to a given cut-off. Of course, in actual clinical practice, one desires to minimize the false-positive rate. In the research study, Bianchini et al. (2008) provide tables with percentile levels for ranges of scores on each of the variables that were found to discriminate the groups. As such, sensitivity for each variable can be determined by examining the percentage of the definite-MPRD performing at a more extreme level than the given score. Specificity at a given score level is also derived from the tables (1-FP rate). The clinician can decide upon various cut-off scores taking into account what is a tolerable false-positive rate. The authors discussed that “useful levels of sensitivity (e.g., greater than 50%) were seen even when the FP rate was kept at less than 10%” (p. 445).
Malingering versus non-malingered symptom amplification. The authors discuss that when assessing chronic pain patients, malingering indicators must differentiate between symptom exaggeration (not malingering) and intentional exaggeration (malingering). The use of an incentive-only group (no malingering) provided an important control for the effects of symptom exaggeration associated with a chronic pain syndrome. In addition, the authors discussed that the findings on the Hs and Hy Scales of the MMPI-2 support the conclusion that exaggeration for reasons other than malingering is seen in patients with financial incentive relative to those without incentive. As can be seen in Table 12, the incentive-only pain patients did produce elevations on Hs and Hy that were significantly higher than the no-incentive pain patient group. However, the elevations were not nearly as high as those found in the definite MPRD group and student simulators. As discussed by Bianchini et al. (2008), “unlike the validity scales, the incentive-only patients were 3 to 4 times more likely to have T-scores greater than 80 on the Hs and Hy scales compared with any of the groups of patients without incentive” (p. 446). The authors go on to state that, “this means that even in the absence of evidence of intentional exaggeration, patients with incentive scored higher (by about 10 points) on these scales.” Even so, the malingering groups (MPRD, student simulators) still scored about 10 points higher than the incentive-only patients and were almost 4 times more likely to score 90 or higher compared with the incentive-only group. This study demonstrates that the MMPI-2 is capable of differentiating intentional exaggeration of physical symptoms in chronic pain (malingering) from symptom amplification due to the complex nature of a chronic pain syndrome.
Evaluation of Cognitive Symptoms
Cognitive complaints frequently occur in patients with chronic pain and it is evidenced that these deficits may be under voluntary control in a significant percentage of patients (see Bianchini et. al., 2005 for a review). Recent research suggests that some of the tests for malingering of cognitive deficits may be useful when assessing chronic pain patients. For instance, Etherton et al. (2005) investigated the use of the Reliable Digit Span (RDS) in detecting response bias of pain-related cognitive impairment. The RDS is a common component of several commonly used clinical neuropsychological test batteries. The RDS is an internal validity indicator derived from the Digit Span Test. The RDS involves summing the longest forward and backward digit strings from the digit Span task. The digit span task generally involves reading a list of random numbers and having the patient recall them (both forward and backwards). Thus, the RDS is the sum of the longest digit strings remembered forward and backward. Although there is some variability in the research, RDS scores of 7 or less have generally been associated with malingering. Thus, RDS scores at or below 7 are rarely or never seen in patients with brain dysfunction and scores in that range imply poor effort, negative response bias, or both. The RDS test is based on the assumption that a person attempting to malinger will perform poorly because it appears to be a test of cognitive ability. Even patients experiencing actual pain perception (either clinical or experimentally induced) do not score in this low range.
The Etherton et al. (2005) study was completed to evaluate the potential impact of clinical pain on RDS performance. The clinical records of 200 pain patients who had been seen for comprehensive evaluation were reviewed. Based on the criteria of Bianchini et al. (2005) these patients were divided into three groups: non-malingering pain patients, definite malingered neurocognitive dysfunction pain patients (
In a series of comprehensive studies, Greve et al. (2008, 2009b, 2009c) investigated the malingering detection accuracy of several symptom validity tests. Stand alone forced-choice Symptom Validity Tests (
Portland Digit Recognition Test (PDRT). The PDRT is an example of a forced-choice procedure in which below chance performance is assessed. The PDRT is a 72 item
Test of Memory Malingering (TOMM). The TOMM is a 50 item recognition test that includes two learning trials. During each learning trial, the patient is shown 50 target pictures of common objects for three or four seconds each, at one second intervals. The subject is then shown 50 recognition panels, one at a time. Each panel contains one of the previously presented target pictures and a new picture. The respondent is asked to select the picture that appeared during the learning trial. The minimum score on each of the recognition and retention trials (no correct answers) is zero, while the maximum score (all answers correct) is 50. As with other SVT’s, this test is extremely resistant to true brain dysfunction and chronic pain.
Word Memory Test (
In Greve et al. (2008), the PDRT, TOMM, and
The other two studies in the series Greve et al. (2009b, 2009c) utilized the known groups design discussed previously. In these studies, chronic pain patients were divided into five groups based on a comprehensive number of variables (Not-MPRD, Indeterminate, Possible MPRD, Probable MPRD, and Definite MPRD). These categories were determined based on an application of the malingering classification methodology discussed previously as developed by Bianchini et al. (2005). In addition, these studies used other comparison groups including those with no incentive and college simulators. For illustration purposes, some of the results are presented in Table 15. One can see the marked discrepancy of results of these
Veracity of the Data and Conclusions
In most cases, the final determination of malingering and its impact on a patient’s impairment will be left to the Trier of Fact. The Daubert Standard (United States Supreme Court, 1993) established rules of evidence regarding the admissibility of expert witness testimony during United States federal legal proceedings. When the Supreme Court issued its opinion in Daubert, it suggested four criteria for determining whether science was reliable and, therefore, admissible:
1) is the evidence based on a testable theory or technique (falsifiable and refutable)
4) is the underlying science generally accepted?
Although some States, including their workers compensation systems, have not adopted Dauber, it is still important that medical-legal examiners understand that they must (should) base their opinions on physical findings and diagnostic procedures with proven scientific reliability and validity, rather than on “expert” beliefs, clinical judgment, or consensus opinions. This is simply a good rule to follow whether or not the expert evaluation is bound by the Daubert Standard. The Daubert Standard is designed to eliminate expert witness testimony that is based on junk science, an “expert hunch”, clinical instinct, or is otherwise without scientific basis. This is much higher than the previous standard that was based on being “generally accepted in the field.” The Daubert Standard allows attorneys to challenge the admissibility of reports, regardless of the source, if the conclusions are not formulated with scientific rigor. The burden of proof is shifted to the doctor who must demonstrate the scientific basis behind the conclusion, and be able to defend it.
Whether or not it applies, being guided by Daubert is certainly appropriate in the evaluation of possible malingering. When an evaluator develops a classification of malingering (or partial malingering), the conclusions should be based upon procedures that are grounded in sound scientific methodology and defensible. This also does the greatest justice to the patient since the classification of malingering often carries with it adverse consequences.
Evaluation of Malingered Pain: A Proposed Method
The following is a framework for evaluating the chronic pain patient within a medical-legal context. As directed by the various resources discussed throughout this course, paying attention to gradations of malingering (Malingering, Partial Malingering; Mild, Moderate, Severe Malingering) is included. All data is gathered on the beginning assumption of a credible patient; however, the evaluator must be amenable to being “guided by the data” and employ methods to test credibility.
Physical Examination and Medical Evaluation
The chronic pain patient will most often be initially evaluated by a physician to assess physical explanations for the pain. The evaluation should include at least the following:
Physical examination relevant to the chronic pain in question (e.g. back pain, CRPS, FMS).
Assess variables in Table 11. A structured interview can help with this process
Obtaining and/or review of appropriate diagnostic tests
Carefully reviewing medical records
Paying attention to all behavioral observation and data
Adding a brief screening test of psychological symptom and possible exaggeration
In the vast majority of medical chronic pain evaluations, the issue of possible psychological factors contributing to the pain (either symptom exaggeration due to the chronic pain syndrome or some level of malingering) is not routinely assessed. The challenge for the physician is to have a “tool” for rapid screening of these issues. Although many lengthy assessments are available (MMPI-2, BHI-2, MCMI-III, etc). There are few brief screening instruments. For this task, consideration might be given to something like the Brief Battery for Health Improvement (BBHI-2). As discussed in the Evaluation and Treatment of Chronic Pain and QME-Chronic Pain Course: II, the BBHI takes about 7-10 minute to complete and provide the following scale results:
Physical Symptom Scales
The BBHI-2 or similar instrument, will not tell the physician why the exaggeration of symptoms might be occurring or the severity of it, but these results are helpful as a guide for more in-depth evaluation.
Analysis of the data. As we have seen, detection of malingering based on the physical examination and medical data is extremely difficult aside from astounding findings (e.g. the 60-Minute type of surveillance in which the disabled back pain patient is working fulltime in construction). Therefore, the guiding rule of “compelling inconsistencies” is the manner in which the data is analyzed. The physician has a wealth of data that can be compared and contrasted across multiple domains. If compelling inconsistencies are noted, then referral for limited neuropsychological testing may be indicated. As we have seen, these evaluations and tests can add a wealth of data to be taken into account.
Neuropsychological Evaluation (Cognitive and Psychological)
If the physical and medical data suggest symptom exaggeration (for whatever reason, malingering or not), a chronic pain-focused neuropsychological evaluation may be appropriate (in this context, I am combining the psychological and neuropsychological assessment). This assessment evaluates the psychological and cognitive aspects of the chronic pain. It also assesses whether the presentation of physical symptoms is being amplified, to what degree, and for what reason. As we have reviewed, a full neuropsychological battery is generally not necessary (unless significant cognitive deficits are being alleged). In most cases, a psychological evaluation along with the SVT’s and the MMPI-2 and other pain-focused tests (e.g. BHI-2, MPI, etc.; See Pain Course II or QME Pain Course II) is probably most appropriate.
The following might be an example of such an evaluation:
Review of medical records
Interview of significant others
MMPI-2, BHI-2, MPI, etc.
SVT’s (e.g. PDRS, TOMM, WMT)
Other NP or pain-specific tests
Review of other data
Again, the guiding principle is the search for compelling inconsistencies. This includes an incorporation of all the data available within and across domains.
Synthesizing the data
After all the data is available, it is analyzed for “compelling inconsistencies” after which a classification can be developed. As we have discussed in this course, the DSM-IV-TR definition is inadequate for several reasons. Another conceptualization might be a combination of the ideas of Banchini (MPRD), Rogers (adaptational model; mild, moderate, severe malingering), and Resnick (full, partial malingering). Pain patient malingering might first be classified according to the MPRD criteria (with all of the operational definitions). To allow for gradations, the concept of a continuum of severity of malingering might be added. This conceptualization captures many more real-life situations that go beyond malingering versus non-malingering. In addition, for those with evidence of partial malingering (concomitant with an actual pain problem and impairment), some estimate of true impairment due to the actual pain problem might be given.
Summary and Conclusions
In many situations, a patient’s level of impairment will directly relate to such things as access to certain medical treatments, financial compensation, and disability status. Evaluation of impairment can be a critical factor in personal injury civil cases, workers’ compensation injuries, social security disability determinations, long term disability insurance benefits, among other things. The assessment of the chronic pain patient presents a particularly challenging situation for the expert since the chronic pain syndrome often involves symptom amplification that is not intentional. This course presents an overview of the differential diagnosis of malingering along with problems with the DSM-IV definition. Alternative conceptual models of malingering are discussed that allow for “gradations” rather than the all-or-nothing categorical approach of the DSM. The course reviews the most recent data on base rates of malingering in chronic pain, which are much higher than previously thought (20%-40%). Even so, other data suggests that evaluation for malingering is often not completed. Based upon a review of the research, an approach to assess the possibility of malingering of chronic pain is discussed including the format of the physical-medical examinations, the use of symptom validity tests derived from neuropychology, psychological tests of symptom amplification, and assessment of cognitive function.
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