Pain, Impairment, and Disability in the AMA Guides Part 2

Saturday, April 22, 2006 | 0

This is the second in a three part series by James P. Robinson, Dennis C. Turk, and John D. Loeser republished with permission from the Journal of Law, Medicine & Ethics, 32 (2004): 315-326.

THE PROBLEM OF SUBJECTIVE FACTORS

However elegant the above syllogism appears to be, it leaves out an important category of information - the self-reports that disability applicants provide about their experiences as they try to engage in activities. These reports provide a first-person perspective that, in principle, might be very important to the assessment of the applicants' disability.

In some instances self-report data address the same phenomena that are addressed by examiners who perform impairment ratings, but from a first-person perspective.

For example, a physician who is examining an applicant with an ulnar neuropathy would assess the severity of the associated impairment on the basis of electro-diagnostic testing and clinical examination. The applicant could also provide information based on his or her experience with the injury, for example, report activities that were difficult for him or her because of it. The difference is that the applicant has a unique, first-person perspective on the limitations that his or her condition imposes, whereas an examining physician performing an impairment evaluation relies on publicly available, third-person information.

In other instances, self-report data provide insights into the experiences of injured individuals that are in principle not available to external observers. These include a variety of aversive experiences - such as pain, fatigue, or subjective weakness - that make it difficult for injured individuals to engage in normal activities. Among people with injuries to the musculo-skeletal or nervous system, pain is the most common of these aversive experiences.

The potential importance of subjective experiences is highlighted by Osterweis and her colleagues in an Institute of Medicine monograph on the role of pain in disability awards by the Social Security Administration:

The notion that all impairments should be verifiable by objective evidence is administratively necessary for an entitlement program. Yet this notion is fundamentally at odds with a realistic understanding of how disease and injury operate to incapacitate people. Except for a very few conditions, such as the loss of a limb, blindness, deafness, paralysis, or coma, most diseases and injuries do not prevent people from working by mechanical failure. Rather, people are incapacitated by a variety of unbearable sensations when they try to work.

Pain and other "unbearable" sensations cannot be incorporated into impairment evaluations as conceptualized in the AMA system for two reasons. First, since pain is inherently subjective, the methods used to assess it violate the tenet that impairment evaluations should be based on objective factors. Secondly, pain and its effects need to be analyzed at the level of the whole person, rather than at the level of a specific organ or body part. People with chronic pain typically attribute their pain and activity limitations to dysfunction of an organ or body part. But these subjective reports are difficult to assess precisely because examination of the involved organ or body part often does not identify abnormalities that make the pain reports inevitable. It often appears to an observer that the affected organ or body part is capable of functioning, but that the claimant does not use it normally because of pain. The observer must consider the person as a whole in order to make sense of the situation. Thus, the assessment of incapacitation secondary to pain violates the tenet that impairment evaluations should assess the functioning of organs or body parts, rather than the functioning of an individual as a whole.

In summary, pain and other subjective factors (such as fatigue or perceived weakness) create a dilemma for impairment - disability evaluation systems. If a system equates impairment with the medical component of disability, it will ignore the subjective factors that often play a dominant role in preventing people from working or engaging in other activities. Such a system would be objective, but might also be somewhat irrelevant, since it would systematically exclude important factors that bear on the ability of an individual to work. Conversely, an impairment-disability evaluation system that affords undue weight to the subjective reports of claimants may inappropriately reward "symptom magnifiers" and "malingerers." The challenge is to develop a disability assessment system that strikes a reasonable balance between the weight given to objective factors (such as amputations) and subjective factors (especially pain).

PAIN AND OTHER SUBJECTIVE FACTORS IN THE AMA GUIDES

The AMA Guides 5th clearly indicates that subjective data - including pain - may be considered in impairment ratings. Specifically, it states: "An impairment can be manifested objectively, for example, by a fracture, and/or subjectively, through fatigue and pain. Although the Guides emphasizes objective assessment, subjective symptoms are included within the diagnostic criteria" (emphasis added). Also, the AMA Guides 5th contains an entire chapter (Chapter 18) devoted to the assessment of pain-related impairment, and mentions pain in several other chapters. Thus, on the surface it appears that the Guides recognizes the importance of pain and other subjective experiences of individuals with injuries.

However, the AMA Guides 5th does not provide a coherent discussion of the problems raised by pain and of the rationale for including pain in its evaluation system. Chapter 18 does consider these issues, but the concepts discussed in it are contradicted in other parts of the AMA Guides 5th. In particular, Chapter 1 of the AMA Guides 5th contains the following statement: "Physicians recognize the local and distant pain that commonly accompanies many disorders. Impairment ratings in the AMA Guides 5th already have accounted for commonly associated pain, including that which may be experienced in areas distant to the specific site of pathology. "This assertion complicates the already difficult task that examiners face when they attempt to combine objective information about the functioning of individuals' organs and body parts with subjective information provided by the individuals about their pain. It seems to imply that examiners should not combine these two types of information because the expert panels who contributed chapters to the AMA Guides 5th have already accomplished this difficult task. We view this implication with skepticism since the AMA Guides 5th contains no information about how the expert panels incorporated pain into their ratings, and no indication that experts in pain participated in the panels. The assertion in Chapter 1 also undercuts the role of Chapter 18. Since it indicates that pain poses no special problems in impairment assessment, it implies that all but the most unusual patients can be evaluated without reference to Chapter 18.

The AMA Guides 5th also contains a critical inconsistency in its conceptualization of impairment that bears on the interpretation of pain. Although impairment is formally defined in terms of dysfunction of organs or body parts, the AMA Guides 5th repeatedly states that the severity of impairment should be conceptualized in terms of the impact of an injury or illness on the ability of an individual to perform activities of daily living (ADLs). Thus, the significance of an abnormality in the functioning of an organ is established by considering the individual as a whole, namely, by estimating the extent to which the abnormality limits the ability of the individual to perform ADLs.

In essence, the AMA system contains two different interpretations of impairment. It indicates that impairment means dysfunction of organs or body parts, but also that the severity of impairment is measured by the impact of a medical condition on the ability of a person to perform ADLs. This creates a semantic quandary since, as operationalists and others have argued, the meaning of any concept is closely associated with its measurement. The meaning of impairment is further obscured by another concept - whole person impairment (WPI). WPI is defined as "percentages that estimate the impact of impairment on the individual's overall ability to perform activities of daily living, excluding work. " WPI is construed as a unidimensional scale ranging from 0% to 100%, with 0% representing no significant loss of function and 100% representing complete incapacitation. WPI provides a common metric, so that, for example, the impact of blindness on a person's ability to function can be compared to the impact of spinal cord injury. The important point for this discussion is that the WPI construct describes the severity of a medical condition in terms of its impact on the whole person, rather than in terms of its impact on an organ or body part. Thus, the WPI construct embodies the interpretation of impairment as an index of the extent to which a person is limited in his or her ability to perform activities of daily living (ADLs).

The different conceptualizations of impairment have important implications for the data that are gathered during impairment assessments, and the way in which they are interpreted. For example, the AMA Guides 5th indicates that examiners should usually use the Diagnosis Related Estimates (DRE) system when they evaluate claimants with low back pain. Impairment categories in the DRE system are defined mainly on the basis of objectively measurable indicators of abnormalities in the structure of the lumbar spine and the function of lumbar nerve roots. The ability of a claimant with a lumbar spine condition to perform ADLs plays almost no role in the DRE system. Thus, the DRE system embodies a conceptualization of impairment as dysfunction of organs or body parts. However, if examiners conceptualized impairment in terms of severity of ADL deficits, their impairment ratings would need to incorporate information about claimants' ability to walk, lift, sit, and so forth. If examiners construed impairment both as a measure of organ or body derangement and as a measure of ADL deficits, they would have no basis for combining data about the structure and function of a claimant's lumbar spine with data about the claimant's ADL deficits, or for deciding what to do should the two types of data conflict.

The equation of impairment with ADL limitations in the AMA Guides 5th also creates a quandary about the methods that might be used in research to test the validity of impairment ratings. A common sense approach to the issue of validating impairment ratings would be to study their ability to predict the extent to which individuals' ability to engage in important activities is compromised.

But the logic of such empirical validation research is negated if severity of impairment is defined in terms of severity of ADL deficits. The AMA Guides 5th does not acknowledge this dilemma. Although it says that research to validate the AMA system should be performed, the AMA Guides 5th says nothing about the methodology that would be appropriate in validation studies. In effect, readers of the AMA Guides 5th are urged to accept impairment evaluation as a fundamental step in the assessment of disability applicants without any evidence of its validity or information about how its validity might be established.

The AMA Guides 5th glosses over the problem of equating severity of impairment with severity of ADL deficits when it states: "Impairment percentages or ratings developed by medical specialists are consensus-derived estimates that reflect the severity of the medical condition and the degree to which the impairment decreases an individual's ability to perform common activities of daily living. "This statement seems to assume a strong association between the severity of a medical condition (measured by objective indices of organ or body part derangement) and the degree to which it decreases an individual's ability to perform ADLs. The AMA Guides 5th does not tell an examiner what to do when, as often occurs in chronic pain, an applicant's ADL deficits appear to be much greater than one would expect on the basis of objective measures of disease severity.

In summary, although the AMA Guides 5th seems to support the inclusion of pain in impairment ratings, this support is vitiated by inconsistencies in the conceptualization of impairment, contradictory information about how examiners should interpret pain, and inadequate guidance about how examiners should combine subjective data with objective data in the determination of impairment.

Moreover, although Chapter 18 of the AMA Guides 5th discusses conceptual issues associated with the inclusion of pain in impairment ratings, the framework elaborated in Chapter 18 is not used consistently throughout the book, and is, in fact, undercut by statements in Chapter 1. In general, it appears that the AMA Guides 5th has addressed pain as an after thought, rather than as a problem that is central to the logic of its assessment system.

STEPS TOWARD A SOLUTION

We have discussed the societal dilemma of determining who is actually disabled, the concept that impairment evaluation provides objective medical information that disability agencies can use in disability determination, the problem of conceptualizing pain and other subjective factors as impairments, and the failure of the AMA Guides 5th to resolve conceptual problems associated with incorporating pain. We will now discuss conceptual clarifications that must be made in order frame questions regarding the appropriate role of pain clearly, and outline arguments for and against the systematic inclusion of pain in impairment ratings.

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This article is republished with the permission of The American Society of Law, Medicine & Ethics 765 Commonwealth Avenue Suite 1634 Boston, Massachusetts 02215 Tel: 617.262.4990 - http://www.aslme.org/

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