Fig. 6.1
A variety of psychosocial factors have been associated with the onset of intractable chronic pain (Biopsychosocial Vortex © 2008 by Daniel Bruns, PsyD and John Mark Disorbio, EdD. All Rights Reserved. Reprinted with permission. BHI 2 © 2003 by Pearson Assessments)
Psychological dysfunction can also lead to the onset of painful conditions. A systematic review of the literature determined that risk-taking is influenced by mood and personality disorder, and associated with an increased chance of injury [8], while another study determined that risk-taking is influenced by personality type [9]. One study found that half of all traumatic brain injury hospitalizations were associated with alcohol intoxication [10], while another study found that patients reporting drug or alcohol abuse were more likely to sustain violent injuries [11]. Consequently, it is not surprising that some research has found that the prevalence of substance abuse disorders in patients with chronic pain is twice as high as that observed in the normal population [12]. Another study of patients being treated in an interventional pain medicine setting explored the prevalence of substance abuse problems. Of those patients with a prior history of drug abuse, 34 % of those who were being treated with controlled substances for pain were simultaneously abusing illicit drugs [13].
Overall, a multitude of psychosocial variables may influence lifestyle, risk-taking behaviors, and health habits that can act to increase or decrease the risk of onset of a medical condition.
Psychological Reactions to a Pain Condition
Serious illness and injury are often life-altering conditions, with a profound psychosocial impact (Fig. 6.1). Not surprisingly, in a study of patients with pain-related disability, 64 % reported one or more diagnosable psychiatric disorders, compared to a prevalence of 15 % in the general population. In this sample, the prevalence of major depression was 25 times higher than that seen in the general population. This finding is especially significant as even minimal levels of depression have been associated with increased rates of service utilization [14] and poorer adherence to treatment [15]. In many cases, though, the direction of the arrow of causality is not clear. For example, while in some cases, depression could be a reaction to a severe injury, in other cases, depression that preexisted an injury may increase the risk that the pain will become chronic [16].
Pain can alternately be associated with anxiety, depression, or anger, depending upon how pain is perceived [17]. Laboratory experiments in pain perception suggest that the presence of depression tends to magnify the perception of pain [18]. Additionally, affective distress combines with pain to produce suffering, and ultimately, this suffering may be more closely associated with the patient’s level of functioning than is the pain itself [19]. Research also suggests that a number of other psychological variables are associated with poor treatment outcome. These include anger [20, 21], neuroticism [22], psychological distress [23–27], relationship with spouse [28, 29], positive or negative perceptions prior to treatment [30–32], maladaptive beliefs [33, 34], and fears of reinjury [31].
Psychological Vulnerability Risk Factors
A review of the literature on psychopathology and chronic pain concluded that psychological vulnerabilities of various types could both increase the risk of onset of chronic pain, plus shape how the pain disorder was manifested. This review also concluded that the dominant emerging perspective is that preexisting but dormant vulnerabilities of the individual may be activated by the stress of an illness or injury [35]. If this proves to be true, this would mean that some patients are inherently at increased risk for disability, but this vulnerability may not appear until an environmental event precipitates it. Consequently, understanding preexisting vulnerabilities is an important part of chronic pain assessment (Fig. 6.1).
If a person who is prone to chemical dependency becomes injured, any subsequent pain could become a rationalization for excessive opioid use [36, 37]. Under such circumstances, the possibility of opioid abuse must be addressed [38]. Similarly, patients may be at increased risk for excessive opioid abuse if they are pain intolerant or feel entitled to be pain-free [39]. Although concerns about regulatory scrutiny can sometimes complicate the clinical decision-making process when prescribing opioids, carefully designed interdisciplinary programs can successfully treat patients at risk for addiction [38, 40]. One study found that patients with histories of substance abuse report higher levels of pain [41], and so distinguishing true pain from drug-seeking behavior becomes a matter of great importance [42]. Related to this, a review of the research determined that positive scores on substance abuse screening measures could identify patients who were at significantly higher risk for aberrant drug-related behaviors in treatment [43].
Patients with personality disorders may have an aberrant reaction to pain and may be at increased risk for chronicity. This hypothesis is supported by five studies of patients with chronic pain. These studies found the prevalence rate of personality disorders to range from 40 to 77 % [12, 16, 44–46], far higher than the estimated 5.9–13.5 % prevalence rate found in the general population [47]. However, a recent study reviewed psychological characteristics of patients with chronic pain and determined that a decrease in pain tends to produce a decrease in signs of personality disorder as well [48]. Thus, dysfunctional traits observed in patients with chronic pain may be partially attributable to the destabilizing effect of pain rather than to an enduring personality disorder. This suggests that estimates of personality disorders in patients with chronic pain could be spuriously inflated.
Non-characterological personality traits or cognitive styles can also constitute risk factors for recovery. For example, patients who are prone to catastrophizing [49, 50] have a low sense of self-efficacy [51], and who are prone to pessimism [52] are at risk for failing to make needed behavioral changes and for generally poor functioning. Conversely, positive personality traits such as perseverance have been found to be associated with favorable outcomes from pain conditions [53]. In general, a history of maladjustment [28], low educational level [54], or the presence of a personality disorder can undermine a patient’s ability to cope satisfactorily with an illness or injury, increase the risk of noncompliance, and thus increase the risk of delayed recovery [47, 55]. Severe psychopathology may sometimes affect pain reports in mysterious ways. For example, patients with dissociative disorders often present with psychogenic pain symptoms [56, 57], and in patients with dissociative identity disturbance (multiple personality), each personality may manifest different pain and disability symptoms [58, 59].
Social Environment Risk Factors
Environmental stressors are known to be associated with numerous psychophysiological reactions (Fig. 6.1). A patient’s social environment includes relationships with family, friends, professionals in the medical setting, and supervisors and coworkers in the workplace. The onset of a disabling condition can stress the family system [60, 61] and leads to family conflicts if the disability prevents the patient from performing expected family responsibilities [62, 63]. The problems arising from these changes can be overcome if the patient is a member of a healthy, supportive family. However, in response to disability, an overly solicitous family may reinforce patient passivity and encourage the patient to adopt a disabled role [64, 65], while a dysfunctional family may exacerbate a patient’s condition.
For example, patients who have experienced adverse childhood experiences, such as childhood abuse, have been found to exhibit increased pituitary-adrenal and autonomic responses to stress compared with controls [66–71] and suppressed immunological resistance to cancer and infection [72–74]. These findings may help to explain the association between stress and poor surgical outcome [75], increased mortality [76–78], and slowed speed of wound recovery [79, 80] observed in numerous studies. Consistent with this, studies have found that psychological traumas in childhood are associated with a poor treatment outcome [75, 81].
Within the medical setting, research has found that the therapeutic alliance between the physician and the patient strongly influences the course of treatment [82, 83]. If the physician is perceived as competent and empathic, a positive relationship can develop. This can facilitate the flow of information between physician and patient and promote patient compliance. In contrast, these studies have found that a poor physician/patient relationship can complicate the recovery process and increase the risk of noncompliance. A history of physical or sexual abuse has also been found to increase the risk of delayed recovery [84, 85], as patients reporting a history of assault may feel more physically vulnerable, exhibit more stress-related symptomatology, and resist examinations that they find threatening [86].
Disability is most often considered in the context of the patient’s ability to be gainfully employed. Consequently, the psychological assessment of disability needs to be especially sensitive to social aspects of the workplace that could influence disability behaviors. For example, escape from a disliked workplace environment may offer considerable secondary gain for the report of medical symptoms, and this may influence the course of recovery. In a longitudinal, prospective study of back pain, job dissatisfaction was determined to be the strongest predictor of future back pain reports [87]. This suggests that the avoidance of a disliked workplace may be a powerful negative reinforcer for both pain and disability behaviors [29].
In addition to avoidance of an aversive workplace, other types of reinforcers are also present in the social environment. Studies have shown that both litigation [88–93] and compensation play a role in treatment outcome [25, 88, 90, 92, 94–98]. In some contexts, an injury can socially empower a patient or increase the attention and support from others. Pain can cause the patient to be assigned to lighter job tasks in the workplace or avoid undesirable chores at home. However, once disability appears, the inability of the patient to function in the workplace often leads to financial distress [99] and a continuation of a downward spiral. Overall, it is not surprising that psychosocial variables have been found to be important predictors of the cost of medical treatment [100].
The lack of English proficiency can impact treatment outcome and disability [101] in a number of ways. The inability to speak English in the USA can make it much more difficult to communicate with caregivers, understand how to fill out paperwork, or in other ways access care. In the immigrant community, though, the effects of a lack of English proficiency may be confounded by a low level of education, and low education has been found to be a separate risk factor for poor medical treatment outcome [54].
Etiologically, while some biopsychosocial disorders have their origin in biology or pathophysiology, others have psychosocial origins. Thus, the assessment of biopsychosocial conditions requires not only assessing biomedical variables but also assessing the psychosocial aspects as well. These assessments are facilitated by the use of psychometric tools.
The Psychological Assessment of Patients with Pain
In a survey performed in 1996, some type of psychological screening was performed in about 70 % of surveyed pain clinics using implantable devices [102]. Since that time, multiple evidence-based medical guidelines have recommended psychological evaluation prior to SCS [103–105], and many insurers now require psychological assessment prior to implantation. More generally, multiple evidence-based medicine guidelines now recommend psychological evaluation for all patients with chronic pain [103–105]. As a result, a similar survey in 2005 found that 100 % of surveyed clinics used some type of psychological assessment for patients being considered for implantable devices for pain [106].
The reason for the increased use of psychological tests for patients with pain is the growing evidence of their utility. A recent extensive review of the literature compared the scientific merits of psychological tests to traditional medical tests [107]. After reviewing 125 meta-analyses and 800 samples, this seminal study concluded that psychological tests are scientifically as good as medical tests and can sometimes predict the outcome of medical treatment as well as medical tests. Specifically, this study of psychological tests concluded that (a) there is strong evidence for psychological test validity, (b) the evidence for psychological test validity is comparable to that of medical tests, (c) psychological test provides a unique source of information, and (d) psychological tests supply information beyond what can be obtained by an interview.
In the assessment of patients with back pain, psychological tests are sometimes stronger predictors of treatment outcome than medical tests. For example, a recent study found that psychometric assessment was better than either MRIs or discography in predicting future back pain disability [108] while another study found that psychosocial variables predicted delayed recovery from back pain correctly 91 % of the time, without using any medical diagnostic information [109]. Multiple research studies have shown that psychosocial factors can predict the results of lumbar surgery [28, 54, 75, 90, 110, 111] or spinal cord stimulation [112] correctly over 80 % of the time, and there is evidence that protocols which integrate psychological and medical assessments can provide improved care at reduced cost [196]. Beyond back pain, research sponsored by the World Health Organization found that psychopathology was a stronger contributor to disability than was disease severity [113].
Psychological Testing Concepts
Psychological tests are developed using the science of psychometrics, which is a mathematical approach to measuring intangible human abilities (such as intelligence or memory), traits (such as personality), and subjective experiences (such as sadness or pain). Bruns and Warren have noted that the science of psychometrics is less esoteric than it would first appear:
Although psychometrics sounds mysterious, it is a science that Western society has come to rely on heavily. Perhaps the most common example of this is that on almost every edition of the news on television, the results of a poll are reported. Scientific surveys, which employ psychometric principals, have an established ability to accurately predict the sentiments of a population, with a known degree of error. In manner analogous to the way that scientific questioning of voters can assess their subjective opinions and predict voting behavior, standardized psychometric instruments can assess subjective states in patients that predict disability [114].
To use an analogy, before a medication is ready for clinical use, rigorous scientific testing is needed to show that it is safe and effective. Similarly, before a psychological test is ready for clinical use, it should be psychometrically standardized. While informal questionnaires may be developed without any scientific method at all, a standardized psychological test is developed using the psychometric principles outlined in a work called the Standards for Educational and Psychological Testing [115]. When a questionnaire has been developed to meet the criteria listed in the Standards, it is said to be a standardized test. Standardized tests offer an efficient and scientific means of gathering information about psychological, social, and medical variables.
To illustrate the impact of a lack of standardization, consider the numerical pain rating scale. Although it may have been used in over 1,000 research studies, it is not standardized, and the following clinical vignette illustrates the effect of this: Suppose a clinician asks a patient, “On a 1–10 scale, how would you rate your pain?” How should the clinician respond if the patient responds with the following questions:
1.
What is a pain level of 10? My other doctor defines a pain level of 10 as pain like having a baby, but you say it is pain so bad I want to die. Which one is correct?
2.
Rate my pain from 1 to 10? Does 1 mean no pain, or is that 0? Should I rate my pain from 0 to 10?
3.
Do you mean my back pain, my leg pain, or my headaches? Or do you want the average of all three? Or maybe the highest?
4.
Do you mean right this second while I am sitting? As soon as I stand up, it is worse.
5.
My pain is a 5 – Is that high? What does the average patient say?
Since the numerical pain rating scale is not standardized, there is no test manual to supply the correct answer to the above questions. Consequently, the clinician could respond to the questions in any number of ways, and this would significantly influence which number the patient chooses to describe the pain. As a result, it has been noted that without a more rigorous method, scores returned by measures such as informal pain rating scales are essentially meaningless [116]. In contrast, with a standardized measure of pain like the BBHI 2, all of the above questions would have a definitive answer [117]. This illustrates the advantage of standardized tests. By imposing a carefully standardized method of asking questions, scoring the responses in a standardized way, and having a norm group to which the scores can be compared, a much more meaningful result is obtained.
Characteristics of a Standardized Test
The characteristics of standardized tests are defined in the Standards for Educational and Psychological Testing, which states that standardized psychological tests are characterized by having a number of features:
1.
Standardized tests are developed to be used for a defined purpose and may have less applicability outside of that purpose.
2.
A standardized test reduces error by having standardized testing materials, standardized administration procedures, standardized instructions, and standardized scoring and interpretation methods, and may even require a standardized type of writing instrument, such as a #2 pencil.
3.
A standardized test must have evidence of validity, demonstrating that the test measures what it intends to measure (e.g., the report of medication side effects such as fatigue and weight gain can cause false-positive findings for depression on some psychological tests).
4.
A standardized test must have evidence of reliability, demonstrating that if the test is administered twice in a short time frame, the results will be very similar.
5.
Standardized tests use one or more reference groups called norm groups, which make it possible to have standardized scores with percentile ranks.
6.
A standardized test takes steps to eliminate gender, race, age, and other biases.
7.
A standardized test has an official manual that has recorded the psychometric details of the standardization process and provides the information needed to use the test appropriately.
8.
The content of standardized tests is controlled by copyright and other methods and cannot be modified by end users, as this would destroy the standardization.
9.
Standardized tests are subject to test security or trade secret restrictions, keeping the details of the test confidential (e.g., if the answers on an I.Q. test were made public, a test subject could appear to be a genius by studying the answers beforehand, and this would invalidate the test).
What Psychosocial Variables Need to Be Assessed in Patients with Chronic Pain?
A recent review proposed what it termed the “convergent model” of biopsychosocial assessment. The term “convergent model” was intended to reflect that while at this time the field has yet to achieve any final determinations about how to perform biopsychosocial assessments, evidence and opinion are beginning to converge [119]. This review identified both cautionary risk factors or “yellow flags” (Table 6.1) and exclusionary risk factors or “red flags” (Table 6.2), and these risk factors were organized within the framework of a biopsychosocial paradigm (Fig. 6.1). Exclusionary risk factors were defined as extreme concerns (e.g., imminent risk of suicide or homicide, active psychosis, or intoxicated at medical appointments), any one of which could be sufficient to delay or exclude a patient from elective medical treatment. In contrast, cautionary risk factors were less extreme concerns (e.g., depression, poor pain tolerance), which, in combination, could negatively impact prognosis.
Table 6.1
“Yellow flag” cautionary risk factors suggested by literature review
Type of risk | Potential cautionary factors | |
|---|---|---|
Affective | Depression | |
Anger | ||
Anxiety (fears, phobias, PTSD, etc.) | ||
Psychological vulnerability | History of substance abuse | |
Personality disorder | ||
Cognitive disorder or low education | ||
Poor coping | ||
Diffuse somatic complaints | ||
Social | Conflict with physicians | |
Job dissatisfaction | ||
Family dysfunction | ||
History of being abused | ||
Worker compensation | ||
Compensation focus | ||
Represented by attorney | ||
Biological | Pain and disability | Extreme pain |
Pain sensitivity | Dysfunctional pain cognitions | |
Pain invariance | Diffuse pain | |
Pain > 2 years | ||
Unexplained disability | ||
Exam | Degree to which patient does not meet medical criteria for procedure | |
No medical necessity of procedure to preserve life or function | ||
Destructive/high-risk elective medical procedure | ||
Procedure specific risks: smoking, diet, attitude toward implant, etc. | ||
History | Similar procedure failed previously | |
No response to any treatment | ||
History of nonadherence to conservative care | ||
No objective medical findings | ||
Science | Insufficient evidence that the proposed medical treatment would be effective | |
Table 6.2
“Red flag” exclusionary risk factors suggested by literature review
Type of risk | Potential exclusionary factors | |
|---|---|---|
Affective | Active suicidal urges | |
Active homicidal urges | ||
Severe depression | ||
Severe anxiety (generalized, panic, PTSD, medical phobia/death fears, etc.) | ||
Severe anger | ||
Mood elevation/mania | ||
Other psychological risks | Psychosis/delusions/hallucinations | |
Active substance abuse | ||
Severe somatization | ||
Pain-focused somatoform disorder | ||
Severe personality disorder | ||
Extremely poor coping | ||
Severe social isolation, family dysfunction, or current severe abuse | ||
Social | Litigation for pain and suffering and pain-related treatment | |
Intense doctor/patient conflict | ||
Biological | Pain | Bizarre pain reports |
Dysfunctional pain cognitions | ||
Extreme, invariant pain | ||
Extreme pain sensitivity | ||
Exam | Medically impossible symptoms | |
Gross inconsistencies between objective findings, symptom reports, and patient behavior | ||
Falsifying information, malingering, or factitious symptoms | ||
Inability to cooperate with treatment due to cognitive or other problems | ||
History | Same treatment failed multiple times in past | |
Abuse of prescription medications, violation of opioid contracts | ||
History of gross noncompliance | ||
Science | Evidence that the proposed medical treatment would be injurious or ineffective given the circumstances | |
The convergent model was tested using 2264 US subjects obtained from 106 sites, and the demographics of the norm groups approximated US census data for gender, race, education, and age. The risk factors identified by the convergent model were assessed in a standardized manner, using the Battery for Health Improvement 2 [120] and the shorter Brief Battery for Health Improvement 2 [117]. US national norms for the prevalence of these risk scores were generated for two groups: community members and patients with a variety of diagnoses being treated in a variety of treatment settings. The norms obtained from these samples allowed the calculation of a risk score percentile rank, which was used to establish empirical benchmarks. This made it possible to answer the question, at what point can the risk factors present be regarded as clinically elevated [119]? Using this method, standardized cautionary risk and exclusionary risk scores were shown to predict both work status and satisfaction with care for patients in multiple treatment groups (spinal surgery, upper extremity surgery, brain injury, work hardening, chronic pain, acute injury, and injured litigants). Repeat testing showed these risk scores demonstrated test-retest reliabilities ranging from 0.85 to 0.91, with no indications of race or gender bias.
Commonly Used Tests for Assessing Patients with Chronic Pain
There are a large number of psychometric tests and questionnaires commonly used to assess patients with chronic pain [121]. When determining what psychological tests to review here, a number of factors were taken into consideration. One evidence-based panel concluded that a psychological test battery for the evaluation of patients with chronic pain would include one or more tests designed for the assessment of medical patients with pain and one or more tests of personality and psychopathology [105]. With regard to selecting each of these types of tests, we would suggest the following criteria, which are that the tests (a) are standardized measures, (b) have been peer reviewed by the Burrows Institute of Mental Measures, (c) have been the subject of multiple empirical research articles in peer-reviewed journals, (d) have been vetted by multiple evidence-based medicine panels reviewing the psychological assessment of chronic pain, (e) [if a pain-related measure] should have been designed and developed for pain assessment, and (f) [if a pain-related measure] should have standardized scores based on a norm group consisting of medical patients, and especially medical patients suffering from chronic pain. Reviews of other psychological tests for pain assessment are available elsewhere [105, 121, 122].
When you apply these criteria to measures of personality and psychopathology, four tests are identified. These are the MMPI-2, MMPI-2-RF, MCMI-III, and the PAI. If you apply these criteria to measures used for the assessment of medical patients and chronic pain, the tests identified are the BBHI 2, the BHI 2, the BSI-18, the MBMD, and the P-3.
The Three MMPIs
The three MMPI (Minnesota Multiphasic Personality Inventory) tests are arguably the most used and most researched psychological tests in existence. The original MMPI™ was published in 1943 and remained in use until the MMPI-2™ was published 1986, after which the original MMPI was phased out [123, 124]. Over the last several decades, the MMPI (and to a lesser degree, the MMPI-2) has been used in numerous studies related to patients with chronic pain and surgical outcome. Overall, the MMPI-2 is currently the most widely used measure of psychopathology and is also a well-researched measure of malingering. With regard to the evaluation of patients with pain and injury, the MMPI/MMPI-2 have historically been the most commonly recommended tests [28, 33, 125–129].
However, the MMPI-2 (Minnesota Multiphasic Personality Inventory-2) also has a number of significant weaknesses. First of all, the MMPI-2 scales are aging and are based on archaic psychiatric constructs dating back to the 1930s, such as hysteria, psychopathic deviate, and psychasthenia. Secondly, the MMPI was developed in a time when much less was known about psychometrics and test construction. As a result, all of the clinical scales contained items that later research concluded should not have been on the scale [130].Third, it has been noted that the MMPI-2 is a lengthy test [126], sometimes prohibitively so [125], as it commonly takes up to 90 min to administer [131], and it takes considerable skill to interpret [126]. Fourth, as the MMPI-2 is not normed or designed for patients with pain, it is prone to overpathologize them [126], especially on its primary scales for assessing depression and somatization [127]. Fifth, despite the length of the MMPI-2, it does not assess many of the variables relevant to medical patients and must be combined with other measures for chronic pain assessment. To this end, Block et al. recommends that the MMPI-2 be used with three other tests [125], Burchiel et al. employed the MMPI-2 and five other tests [33], Doleys and Olson discussed the use of the MMPI-2 and seven other tests [126], Beltrutti et al. discussed the MMPI-2 and eight other tests [129], and Olson et al. employed the MMPI-2 and 10 other tests [128]. Given that the MMPI-2 is already a long test, this makes for a very lengthy test battery.
After much debate, the MMPI-2-RF™ (Minnesota Multiphasic Personality Inventory-2-Revised Form) was published in 2008 [130, 132]. This test has been called a radical departure from the MMPI-2 [133]. While most of the MMPI-2-RF scales were derived from MMPI-2 scales, none are identical, many are markedly different, while others are totally new [130, 132]. In addition to about 80 measures of psychopathology, the MMPI-2 has 15 “validity scales” used to detect exaggerating or concealing information. In contrast, the MMPI-2-RF has 50 scales including eight validity scales. The term “validity scale” is used to convey that these scales attempt to determine if the patient’s test responses are valid representations of his or her true feelings or if the patient is attempting to “fake” or appear better or worse than he or she actually is by biasing the information that is presented [114]. The goal of the MMPI-2-RF development was to address the MMPI-2 shortcomings mentioned above and produce a shorter and more psychometrically sound test. Unfortunately, while there were 60 years of research on the original MMPI/MMPI-2 scales, the changed scales in the MMPI-2-RF mean that these decades of research have at best only moderate applicability to the MMPI-2-RF test.
The difference between the MMPI-2 and the MMPI-2-RF is illustrated in one study of 7,330 patients, which found that the “code type” (traditionally used to determine how the test was interpreted) agreed only 14.6 % of the time [134]. Additionally, research suggests that the MMPI-2 is substantially more likely to return a profile suggestive of psychopathology [134] or somatoform disorder [135] than the MMPI-2-RF. Overall, even though these two tests share the same name, it is probably better to think of the MMPI-2-RF as a distinctly different test. At the date of this writing, no published studies were found that utilized the MMPI-2-RF to assess patients with chronic pain. Further, it has been noted that the MMPI-2-RF Revised Clinical Scales were optimized for psychiatric assessment, and without consideration for use with medical patients or assessing somatic symptoms, possibly making them less useful for that purpose than the MMPI-2 [135]. Overall, while the relative merits of the MMPI-2 and the MMPI-2-RF tests remain the subject of ongoing debate [136, 137], both tests will likely remain popular measures of psychopathology.
The MCMI-III
The MCMI-III™ (Millon Clinical Multiaxial Inventory III) is another widely used measure of general psychopathology [138]. One of the MCMI-III’s most distinctive features is that among its 25 scales are scales for the assessment of a variety of types of personality disorders, which is helpful for differential diagnosis. While the MCMI-III has the distinct advantage that its scales are keyed to DSM-IV diagnostic criteria, this will be less of an advantage once DSM-5 is released.
A feature of the MCMI-III that could be seen as either a strength or a weakness is its utilization of what are called “base rate” scores. These scales employ a psychometric method where a base rate score of above 75 suggests that some aspects of a syndrome are present, while base rates scores above 85 suggest that the full syndrome is present. While this represents an advantage in some respects, on the negative side, this psychometric method is not based on the normal curve and cannot be used to generate a percentile rank. This makes it somewhat more difficult to identify statistical outliers, but easier to identify the degree to which a particular syndrome might be present. Another feature is three validity scales and one measure random responding.
With regard to its applicability to patients with chronic pain, there is some research on the MCMI-III with regard to its use with chronic pain patients [139–141]. However, it was developed with and normed on psychiatric patients. Consequently, while the MCMI-III is a valuable measure of psychopathology, it must be remembered that like the MMPI-2 and MMPI-2-RF, its use with patients with objective physical disease or injury may lead to spuriously elevated scales scores, as patient reports of physical symptoms may inflate some of its measures of psychopathology.
The PAI
The PAI™ (Personality Assessment Inventory) is also a popular measure of general psychopathology. Psychometrically, the PAI is a carefully constructed measure, whose 22 scales assess a broad cross section of affective, characterlogical, and psychotic conditions. Like the MMPI-2, the PAI uses standardized T-scores based on community norms, which allows it to identify statistical outliers. The PAI, however, is substantially shorter than the MMPI-2, about the length of the MMPI-2-RF, but considerably longer than the MCMI-III. The PAI has four validity scales.
Some research has studied the applicability of the PAI to assess chronic pain patients [142, 143]. Like other psychological inventories designed for assessing psychiatric patients, it utilizes items about physical symptoms to diagnose depression, anxiety, and other conditions. Consequently, as with the MMPIs and the MCMI-III, it will tend to overestimate some forms of psychopathology in patients with chronic pain.
Psychological Measures for Medical Patients
As noted above, while the MMPIs, the MCMI-III, and the PAI are well-established measures of psychopathology, they are at risk for overestimating psychopathology when used with medical patients. One reason that this happens has been called the “psychological fallacy” [117], which is a problem that occurs when psychological measures intended for psychiatric patients are given to medical patients.
Most psychological tests of psychiatric conditions utilize items about physical symptoms. For example, a measure of depression might contain items about psychological symptoms (e.g., negative thoughts and sad feelings) and physical symptoms as well (e.g., fatigue, loss of libido, changes in weight). However, it has been noted that physical symptoms of this type can also be the product of injury, disease, or medication side effects. Thus, when patients report their medical symptoms on such measures, it can spuriously increase their scores on measures of psychiatric conditions. This is true not only of the MMPIs, MCMI-III, and PAI but also other common measures such as the Beck Depression Inventory [144]. In contrast, a few tests, such as the State Trait Anxiety Inventory [145] or the Battery for Health Improvement 2 [120], control this problem by avoiding the use of items containing physical symptoms to assess emotions. Another important difference in psychological measures designed for medical patients is that they are normed on medical patients, rather than psychiatric patients or community members. By comparing a patient to a group of other patients, it is much easier to identify the unusual, at risk patient [105].
The BHI 2
The BHI 2™ (Battery for Health Improvement 2) is a test designed for the biopsychosocial assessment of medical patients [120]. This test had its origins in a biopsychosocial paradigm (Fig. 6.1) and as such attempts to assess the medical, psychological, and social aspects of a patient’s condition. A strength of the BHI 2 is its norms, which include both patient and community samples. Beyond this, however, the patient norms are broken down into a number of subcategories. About half of the BHI 2 patient norm group consisted of patients with acute injury or other conditions, while the other half consisted of patients with chronic conditions including patients with orthopedic injury, brain injury, headache, fibromyalgia, CRPS, and other conditions. Further, diagnosis-specific pain norms were developed for six groups, which were chronic pain, lower extremity injury, low back injury, upper extremity injury, neck injury, headache, and head injury. This allowed for many patients’ pain reports to be compared to other patients in their own diagnostic category. While the BHI 2 uses pain norms for a variety of injury types, other aspects of the BHI 2 were designed to assess conditions unrelated to injury, such as somatic preoccupation and somatization, death fears, the perception of addiction to prescription medication, the tendency to become physically tense when under stress, the perception of disability, and negative attitudes toward physicians that have been found to be associated with thoughts of litigation [146, 147] and violence [148, 149]. Additionally, in order to avoid the psychological fallacy, the BHI 2’s 18 scales and 40 subscales assess the thoughts and feelings associated with depression and anxiety separately from the physical symptoms associated with depression and anxiety. Overall, since the BHI 2 was designed to assess medical patients in general and patients with chronic pain in particular, it assesses most of the risk factors identified in the literature [119]. The BHI 2 has a measure of random responding and two bidirectional validity scales, giving it two measures of exaggerating complaints and two measures of concealing information.
Weaknesses of the BHI 2 include that while it assesses some aspects of psychopathology, especially relevant to medical patients, it was not intended to assess the breadth of psychiatric conditions assessed by inventories designed for psychiatric patients. For example, it uses only critical items to assess psychosis and makes no attempt to assess mania, obsessive-compulsive disorder, and some other types of severe psychopathology. Additionally, while there is a growing body of BHI 2 research related to chronic pain [39, 119, 146–161], its research base is not as extensive as that of the MMPI/MMPI-2.
The MBMD
The MBMD™ (Millon Behavioral Medicine Diagnostic) is a psychological test designed for use with medical patients [162]. Like the BHI 2, the MBMD is theory driven, being based in part on Millon’s “Evolution-based Personality Theory” [163], with the resulting coping styles being applied to the medical setting. The MBMD could be said to be the psychometric cousin of the MCMI-III, as it adapts many of the MCMI-III scales for use in a medical setting. Like the MCMI-III, the MBMD uses base rate scores. As with the MCMI-III, the strength of this approach is that it attempts to identify patients above a certain level of symptomatology, at the expense of being unable to identify statistical outliers or generate a percentile rank. The MBMD differs from the MCMI-III, however, in that while the MCMI-III attempts to assess psychopathology, the MBMD is designed to assess less extreme aspects of the same constructs that are likely to be observed in a nonpsychiatric population. For example, while the MCMI-III has a scale measuring schizoid tendencies, a similar scale on the MBMD assesses introversive tendencies.
The MBMD is a test designed for medical patients and was constructed using patients with heart disease, diabetes, HIV, and neurological problems. However, only 9 % of patients in the original patient normative group were reported to be suffering from chronic pain. More recently, bariatric and chronic pain norms for this test were also developed. The MBMD pain patient computerized interpretive report displays both the original general medical norm profile using base rate scores and a pain patient norm profile using normative scores. This produces a pain patient profile that is far less elevated than that produced by the original norm groups and adds a measure of complexity to the interpretation. Perhaps because of this, the pain patient interpretive report continues to be based on the original general medical norms. At the time of this writing, no research studies were found that applied the MBMD to patients with chronic pain.
The MBMD’s 38 scales excel at describing the patient’s coping style, health habits, potential for certain types of negative reactions to treatment, and factors which may potentiate the patient’s distress. It also excels at the psychological assessment of medical patients who are more or less psychologically normal and is also unique in that it offers a brief assessment of spiritual resources for coping. The MBMD also has three validity measures for assessing a patient’s test-taking attitude.
The BBHI 2
The BBHI 2™ (Brief Battery for Health Improvement 2) is a short (10-min) version of the BHI 2. The BBHI 2’s six scales measure a number of concerns commonly seen in medical patients and especially those with chronic pain: depression, anxiety, somatization, pain, functioning, and utilization of the same norms as the BHI 2 [117]. With regard to pain, the BBHI 2 assesses pain preoccupation, pain tolerance, pain location, pain variability, and dysfunctional pain cognitions. Additionally, it uses critical items to screen for 15 other concerns such as satisfaction with care, home life problems, addiction, psychosis, sleep disorders, panic, compensation focus, and suicidality.
A strength of the BBHI 2 is that it assesses a wide variety of risk factors in a short amount of time [119] and it is the shortest psychological inventory to have validity measures for exaggerating, concealing information, and random responding, and a critical item for psychosis as well. In addition to being used diagnostically, the BBHI 2 can also be used in a serial fashion to track changes in pain, function, depression, anxiety, and somatic distress over the course of time in treatment. A weakness of the BBHI 2 is that outside of its core scales, it screens for a number of concerns using critical items, which is a less reliable method than that which can be obtained with a longer instrument.
The P-3
The P-3™ (Pain Patient Profile) is a short measure useful within pain practices [164]. The strength of the P-3 is its parsimony. The P-3 assesses three critically important variables: depression, anxiety, and somatization. Although the P-3 is tightly focused on these three scales, one strength is that these scales have unusually high reliability. Another strength is that the P-3 utilizes both chronic pain and community norms in interpreting these scales. The appeal of the P-3 is its elegant simplicity, the strength of its norms, and its intended use with patients with chronic pain. The P-3 also has a growing base of empirical research studies pertaining to chronic pain [141, 165–173]. The primary weakness of the P-3 is that there are many risk factors it does not assess, such as coping, pain, functioning, and substance abuse.
The BSI-18
The BSI-18® (Brief Symptom Inventory 18) [174] is an 18-item version of the much longer Brief Symptom Inventory [175], which in turn was derived from the SCL-90 test [176]. Like the P-3, the BSI-18 has three scales: depression, anxiety, and somatization. Thus, it shares the P-3’s parsimonious, straightforward approach, and on the surface, the BSI-18 appears identical to the P-3. However, these tests differ in three important respects. First of all, BSI-18 is much shorter than P-3, taking only about one-third of the time to complete. Secondly, while the BSI-18 scales are shorter, they also have lower reliability than the P-3 scales.
A third difference is that while the P-3 was normed on both community members and patients with chronic pain generally, the BSI-18 was normed on patients suffering from cancer-related pain. Thus, while both tests have pain norms, the two normative groups were quite different. Overall, the meaningfulness of a patient’s scores on a standardized test is influenced by the degree of similarity between the patient and the norm group to which the patient is compared. Overall, the strength of the BSI-18 is assessing the psychological distress of patients with cancer [177–180].
Other Noteworthy Pain-Related Questionnaires
There are a multitude of other questionnaires pertaining to pain [121] which did not meet all of the criteria for review here, but which are nevertheless noteworthy. Three of these are the West Haven-Yale Multidimensional Pain Inventory (WHYMPI or MPI) [181], the Chronic Pain Coping Inventory (CPCI) [182], and the Survey of Pain Attitudes (SOPA) [183]. The MPI is a well-researched questionnaire that offers scales to assess attitudes about pain, the perceived attitudes of others toward the patient’s pain, and the impact of pain on functioning. Weaknesses of the test include that it is not a standardized test: It does not have a formal test manual and has multiple versions [184] with alternate instructions, which have been found to significantly alter the results [185].
Conversely, the CPCI and the SOPA are both questionnaires used in research that evolved into different, standardized versions that kept the same name. Both tests are also similar in that they assess a number of variables directly related to pain. As aptly suggested by its name, the CPCI assesses a variety of strategies patients may use to cope with pain, which include three illness-focused coping strategies and six wellness-focused strategies. A weakness of this test is that it lacks a pain catastrophizing measure. The SOPA is also well researched and assesses a patient’s beliefs about pain, which include two scales assessing adaptive beliefs and five scales assessing maladaptive beliefs. Both of the CPCI and the SOPA perform the important task of assessing attitudes, beliefs, and behaviors about pain. A weakness of both the CPCI and the SOPA is that their norms lack diversity in several respects, such as including less than 2 % African-American and Hispanic patients. Overall, the CPCI, SOPA, and MPI are all alike in that they all measure variables directly related to pain. However, none of these scales assess psychopathology or faking, and so they would probably best be paired with another measure.
Validity Assessment
Patients are sometimes motivated to falsely report pain or disability. Incentives range from primary gain (i.e., the individual finds some intrinsic satisfaction in being a patient, such as in being a suffering, tragic hero), secondary gain (i.e., the patient receives monetary, opiate, or other rewards for reporting pain), or tertiary gain (i.e., someone the patient cares about, often a family member, receives monetary or other rewards when the patient reports pain). Since pain is a subjective experience, reports of pain are easily faked [186], and false reports of pain are sometimes associated with malingering. An extensive review of pain-related malingering examined 68 studies and concluded that malingering was present in 1.25–10.4 % of patients with chronic pain [187]. Other more recent studies have suggested that there may be a 30–40 % incidence of malingering of pain or other symptoms in patients who were litigating or seeking benefits [188, 189] and that reports of symptoms increase when monetary compensation for them is present [190–192]. To detect these tendencies, psychometric measures called validity scales are used.
Validity measures are common features on major psychological inventories, and the MMPI-2, MMPI-2-RF, MCMI-III, PAI, BHI 2, and MBMD all have multiple validity scales. Of these, the MMPI-2 and MMPI-2-RF easily have the greatest number of and the most researched validity measures. With regard to brief psychological measures for pain, only the BBHI 2, P-3, and SOPA have validity measures. The BBHI 2 includes assessments of exaggerating, denial, random responding, and psychosis, while the P-3 has a measure of bizarre responding and the SOPA has a measure of inconsistent responding. Validity measures in general look for patterns of complaints that are so strange, improbable, or extreme as to be extraordinarily unlikely. This could involve claiming on a questionnaire to have never had a bad feeling or reporting a pattern of symptoms that is extraordinarily unlikely.
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