Pain, Impairment, and Disability in the AMA Guides Part 1

Saturday, April 8, 2006 | 0

By James P. Robinson, Dennis C. Turk, and John D. Loeser Journal of Law, Medicine & Ethics, 32 (2004): 315-326.
Copyright 2004 by the American Society of Law, Medicine & Ethics.

Back injuries have a bad reputation. The workman looks upon them with apprehension, the insurance company with doubt, the medical examiner with suspicion, the lawyer with uncertainty... The medical examiner is faced with the difficulty of estimating the true value of the subjective symptoms in the comparative absence of physical signs. His suspicion is born of the frequent disparity between these two. "This prophetic statement made almost 100 years ago highlights an ongoing problem - how people who are incapacitated by painful conditions such as chronic low back pain can be evaluated consistently and equitably for purposes of disability compensation. We confronted this vexing problem when we participated in writing the chapter devoted to impairment associated with pain (Chapter 18) of the American Medical Association's Guides to the Evaluation of Permanent Impairment, 5th edition (AMA Guides 5th). Our purposes in this essay are to clarify several important conceptual issues associated with the assessment of pain among disability applicants, and to articulate reasons why pain should be considered in impairment and disability ratings.

CAVEATS

We will discuss pain assessment primarily in relation to the Guides to the Evaluation of Permanent Impairment, 5th edition although the issues we raise are relevant to other impairment-disability evaluation systems as well. We focus on conceptual issues rather than specific pain assessment methods, which we have discussed elsewhere. Also, we limit our discussion to musculo-skeletal and neurologic injuries, for the practical reason that these are the types of conditions seen most frequently during impairment-disability evaluations. We consider only injuries in which a person has objective evidence of impairment in the sense of derangement of an organ or body part, but reports incapacitation from pain that exceeds the limitations that can be clearly derived from the measurable impairment. An example is a person with objective evidence of a persistent L5 radiculopathy who reports that her back and leg pain prevent her from walking or sitting for more than 5 minutes at a time. We suggest that if consensus about the appropriateness of pain assessment can be achieved in this "simple" situation, future efforts can be directed toward determining its appropriateness when there is no evidence of organ or body part derangement (e.g., fibromyalgia syndrome, migraine), or when patients' pain reports appear to be determined primarily by psychological factors (somatoform disorders).

Any attempt to clarify issues related to the assessment of pain in the AMA system is confounded by the conceptual ambiguities, inconsistencies in usage, and lack of scientific validation that pervade the entire system. The paucity of research on the AMA system is striking, given the fact that evaluations based on it determine the allocation of billions of dollars in medical and wage replacement payments. In the absence of scientific data, the AMA system relies almost exclusively on the opinions of panels of medical consultants. Unfortunately, no details have been published about how the expert panels were selected or the processes they followed to reach decisions about impairment. Moreover, since several different groups of experts contributed to the AMA Guides 5th, there are significant inconsistencies throughout the text. The combination of inadequate validation research and ambiguity regarding the expert panels makes it difficult for us or any other observers to determine which elements of the AMA system are well substantiated, and which ones need significant revision.

Another source of ambiguity is that the AMA system as actually used during impairment and disability evaluations often differs from system as described in the AMA Guides 5th. The disability agencies and insurance companies that use the AMA Guides 5th often gravitate toward what has been called "the administrative model" of disability. A fundamental premise of this model is that disability should be transparent, in the sense that the subjective reports of a disability applicant should be verifiable by objective evidence of a medical condition that imposes significant activity limitations. Because of this conceptual model, disability agencies and insurance companies generally emphasize objectivity in assessments more than the AMA Guides does. For example, they routinely instruct physicians who perform independent medical examinations to base conclusions strictly on objective findings. As a more dramatic example of the demand of disability agencies for objectivity, the largest workers' compensation carrier in Washington State recently ruled that it would not use Chapter 18 (the pain chapter) of the AMA Guides 5th because of its subjectivity. The general point is that the AMA Guides 5th has sometimes been used in ways that stray from the intent of its authors and editors.

Finally, key concepts such as "impairment" and "disability" are defined so ambiguously that their applicability to pain is difficult to ascertain. As discussed below, these ambiguities obscure dilemmas associated with the assessment of pain.

Because of the aforementioned ambiguities and inconsistencies, the majority of this essay is devoted to clarifying basic issues, including the reasons why impairment-disability evaluations are performed in the first place, the meanings of key concepts, and the ways in which pain is construed in the AMA Guides 5th. Following these clarifications, we articulate reasons for including pain in the medical evaluation of disability applicants, and the implications of incorporating pain assessment systematically in the AMA Guides 5th.

THE SOCIETAL CONTEXT

Communities frequently provide assistance to individuals who are incapacitated. This type of helping behavior can be seen not only in modern societies, but also in primitive ones and even in communities of infrahuman primates.

Tolerance toward and care of the sick, infirm, injured, and disabled appears to be a fundamental feature of society dating back to prehistoric times. Formal disability compensation systems date back at least 4000 years to the Babylonians, who provided compensation for loss of life or a body part incurred in the service of the state. During the time of ancient Egyptians and Greeks the state provided compensation for injuries caused by a wrongful act or occurring in the context of military service, respectively. Contemporary approaches to the issue of assistance for incapacitated people can be traced back to social insurance programs instituted in Germany in the late 19th century. Modern assistance programs include those addressing incapacitation stemming from work, and others addressing incapacitation among the indigent. In addition, tort law allows persons who have been injured because of the negligence of others to receive compensation for their losses.

In all these instances, some method is required to determine whether people who seek benefits are actually disabled; namely, whether they have medical conditions that significantly limit their ability to carry out certain activities. Among individuals who allege disability, ones who are truly disabled need to be distinguished from ones who cannot perform activities because of non-medical circumstances (e.g., inability to find work due to an economic depression), and from ones who will not perform activities, even though they are capable of doing so. Physicians are often enlisted to make the above distinctions by objectively evaluating medical factors that may underlie a claimant's allegations of incapacitation. Sometimes the agencies that administer disability programs establish their own procedures for the medical evaluation of disability applicants. For example, the United States Social Security Administration has followed this path. More commonly, disability agencies rely on the system developed by the American Medical Association, and require physicians to follow the AMA Guides 5th when they evaluate disability applicants. Thus, the AMA Guides 5th has a unique role in that its medical evaluation procedures are used by multiple disability agencies.

For at least the past 45 years, objective medical assessments of disability applicants have been called impairment assessments. Impairment is defined in the AMA Guides 5th as "A loss, loss of use, or derangement of any body part, organ system, or organ function. "As this definition indicates, impairments are viewed as biomedical abnormalities that can be analyzed at the level of organs or body parts. Thus, for example, a physician could assess renal impairment on the basis of creatinine clearance or cardiac impairment on the basis of ejection fraction.

Although the abstract definition of impairment may seem clear, multiple anomalies and subtleties are encountered when one tries to distinguish between impairment and disability in certain contexts. In the face of this ambiguity, a simple rule that usually applies is that impairment refers to a "part" of a person in the sense of an organ, body part, or physiologic function, whereas disability refers to voluntary behavior at the level of the whole person. This distinction is reflected in the syntax used to describe impairments and disabilities. For example, one would say "Ms. Smith's right leg is weak because of her polio" to describe her impairment, and "Ms. Smith is unable to walk up stairs" to describe her consequent disability.

Impairment evaluations appear to satisfy the societal need for objective verification of the medical component of a disability applicant's alleged activity limitations. Since they are based on biomedical research, impairment evaluations appear to be scientific. Also, they appear to be objective, since the functioning of organs and body parts can often be assessed and interpreted relatively independently of the persons to whom they belong. Thus, analyses at the level of organs or body parts bypass the complications that arise when examiners try to understand claimants at the "whole person" level, or to perform analyses that rely on claimants' self-reports and voluntary behavior.

In practice, disability agencies frequently rely on impairment evaluations. For example, agencies that administer work disability programs often combine impairment data with non-medical data (e.g., educational background and prior work history) to determine whether an individual is actually disabled from work. The logic of this approach can be summarized as follows:

1. Work disability results from a combination of medical and non-medical factors

2. Impairment evaluations measure the medical component of disability; namely, the severity of medical factors that contribute to work disability.

Therefore,

3. Work disability awards should be based on impairment evaluations supplemented by non-medical data.

The next installment in this series looks at problems with subjective factors in the AMA Guides.

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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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