Introduction
Reading all 600-plus pages of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, is not a practical endeavor, even for treating physicians and independent medical evaluators who frequently conduct impairment rating (IR) evaluations. A physician may choose to focus on a few select chapters depending on the physician's treatment specialty and referral preferences. For example, an orthopedic surgeon who treats only pathologies of the hand and wrist may choose to evaluate only upper extremity injuries. He or she may feel the need to read only Chapter 15, The Upper Extremities. An orthopedic surgeon who is more of a generalist may want to receive referrals for all of the musculoskeletal injuries. As a result, he may read the three musculoskeletal chapters of the AMA Guides: Chapter 15, The Upper Extremities; Chapter 16, The Lower Extremities; and Chapter 17, The Spine and Pelvis. This focused approach is obviously necessary considering the time constraints and treatment specialties of most physicians who accept workers' compensation cases. However, it can also result in a physician who is not knowledgeable about some very basic rating principles.
Prerequisites
To be competent in the use of any chapter in the AMA Guides, Sixth Edition, the physician must also, at a minimum, read Chapter 1, Conceptual Foundations and Philosophy, and Chapter 2, Practical Applications of the Guides. These chapters provide the necessary context to understand the rationale and overriding principles that are common to all chapters. If, as an evaluating physician, you have ever wondered whether a rating may be expressed as a fraction or decimal, how ratings from different extremities and organ systems are combined, whether a patient with a chronic and likely fatal disease was at maximum medical improvement, or what the relative whole person value of the upper extremity is to the lower extremity, then Chapters 1 and 2 are for you. This article uses the salient points listed in Table 2-1, Fundamental Principles of the Guides (6th ed, 20), as an analytical framework for achieving a holistic understanding of the AMA Guides, Sixth Edition.
AMA Guides' Purpose
The AMA Guides serves primarily as “a tool to translate human pathology resulting from a trauma or disease process into a percentage as the whole person” (6th ed, 19). This whole person impairment rating helps jurisdictional professionals determine “financial compensation” for people who “have suffered measurable physical and/or psychological loss” (6th ed, 20). Thus, one goal of the AMA Guides is to bring consistency to the impairment rating process and, thus, equity. Consistency starts with a formalized philosophy that underlies a standardized approach to interpreting objective factors. Subjective complaints, therefore, should ordinarily be accompanied with “demonstrable clinical signs” to be ratable under the AMA Guides, with a few exceptions (6th ed, 24). In all cases, the physician should rely on objective clinical evidence as much as possible.
AMA Guides' Fundamental Principles
Table 2-1 includes a list of 14 overarching principles that are consistent throughout the AMA Guides, beginning with principle 1: “Concepts and philosophy in this chapter are the fundamental principles of the Guides” (6th ed, 20). The table lays the groundwork from which the rest of the chapters are built. For example, principles from this list can be offered as a rationale for why a physician chooses to use the range of motion method rather than the diagnosis-based impairment method—see principle 12: “If the Guides provides more than one method to rate a particular impairment or condition, the method producing the higher rating must be used.” As another example, the principles can offer rationale as to why a physician chose a functional history grade modifier that was lower than that chosen by either the treating physician or the independent medical evaluation (IME) physician; see principle 13: “Subjective complaints that are not clinically verifiable are generally not ratable under the Guides.” An IR expressed as a fraction or decimal may be a good indication that the evaluator is not familiar with the AMA Guides; see principle 14: “Round all fractional impairment ratings, whether intermediate or final, to the nearest whole number, unless otherwise specified.” An IR report that summarizes and analyzes the patient's history and the results of the physical examination and that provides a detailed, yet accessible, explanation on how the physician calculated the rating may be indicative of a highly trained evaluator; see principle 7: “A valid impairment evaluation report based on the Guides must contain the 3-step approach described in Section 2.7.”
According to principle 4, the physician must rate an impairment using the chapter that is the most relevant “to the organ or system where the injury primarily arose or where the greatest dysfunction consistent with objectively documented pathology remains.” In addition, regardless of which chapters are used, no IR may exceed 100% (principle 2); all regional impairments of the same extremity should be combined at the same level first, then “combined with other regional impairments at the whole person level” (principle 3); permanency should not be quantified unless the injured worker has achieved maximum medical improvement (principle 5); and only “physicians duly recognized by an appropriate jurisdiction should perform such assessments” within their field of expertise (principle 6).
Impairment Rating Report
The more detailed, accessible, and transparent a final IR report is, the better. At a minimum and to be in keeping with the fundamental principles of the AMA Guides, the physician is required to divide her report into three distinct sections: clinical evaluation, analysis of findings, and discussion of how the IR was calculated (6th ed, 28). A report without one or more of these sections shows conclusively that the evaluator's report is not in keeping with basic AMA Guides methodology. The structure of the report is not a minor detail, nor does it follow into the realm of physician discretion. The AMA Guides explicitly states that the “3-step process is required [emphasis added] by the examiner to estimate impairment according to the Guides” (6th ed, 28).
The report should be divided into three distinct sections: clinical evaluation, analysis of the findings, and discussion of how the IR was calculated. Section 1, Clinical Evaluation, is subdivided into three subsections: patient history: introduction and overview, physical examination, and claimant's chronological medical history for this injury. This organizational structure parallels that found in section 2.7a, Clinical Evaluation, which requires “the relevant history […] obtained by a review of medical records reflecting past medical history and the patient's presentation of the current history” (6th ed, 28) and a physician examination “performed in a manner and setting that facilitates the effective communication between the patient and the examiner, thereby decreasing anxiety and increasing concentration and effort” (6th ed, 28).
The introduction and overview subsection should contain a contextual history of the injury as derived from the examinee. This means the physician will ask the injured worker to explain what happened. The injured worker should be asked to share information regarding her treatment for the injury in question, treatment outcomes, periods of unemployment, current symptoms (as described by the injured worker, not the physician), current medications, and current limitations on activities of daily living.
Finally, the last part of section 2.7a emphasizes the importance of reviewing “all available diagnostic studies and laboratory data” (6th ed, 28). This should be done before performing the evaluation to help resolve apparent discrepancies among the record review, the interview, and the examination (6th ed, 28).
The physical examination subsection should include the injured worker's height and weight and relevant clinical information (examination findings).
The claimant's chronological medical history for this injury, including the dates and results of diagnostic tests and imaging, is a separate section of the report. The review should also make clear whether the physician reviewed the actual images or imaging reports (or both). Surgical procedures should be listed. Operation reports should be included in the body of the impairment report. Several operations are “diagnoses” in the AMA Guides tables. If the examiner does not have the actual operation report, she may miss factors for which impairment should be rated. If radiculopathy is suspected, the results of sensory testing (including sharp/dull discrimination), motor testing (strength), and reflexes should be provided as well as atrophy measurements for both injured and contralateral limbs. Range of motion measurements, if limitations are suspected, should be given for all planes of the joint in question and for both the injured limb and the uninjured contralateral limb so that anyone with a copy of the AMA Guides, whether physician or judge, can check to see if anything was omitted and that the arithmetic is correct.
Appropriately enough, the second main section of the report should share its name with the second section in the AMA Guides' report process, i.e., the analysis of the findings. In this section, the physician should answer very directly, for the record, questions such as, “Does the claimant have a permanent impairment?” and “Has the claimant reached maximum medical improvement?” The physician should then list all the diagnoses for which there is “a ratable permanent impairment causally related to the work injury or exposure in question.”
Step 3 of the report process involves the third main section of the IR report, the discussion. In this section, the physician shows clearly, in terms that both medical and legal professionals can understand, how the rating was derived. The physician should explicitly state which IR method is most appropriate and why. If applicable, the physician should list what diagnosis line was used and what table and page number it came from. The impairment class and grade modifiers should also be provided, along with the rationale for choosing them. If the net adjustment formula was used, the physician should write it out and show how individual adjustments add up to form the net adjustment. If there are multiple ratable impairments, the physician should follow the above process for each of them and combine them using the appropriate methodology, the Combined Values Chart found as Appendix A (6th ed, 604–606).
Summary
In addition to reading chapters relevant to the physician's specialty, the rating physician must also read Chapters 1 and 2 of the AMA Guides, Sixth Edition, being particularly mindful of the overarching principles presented in Table 2-1 (6th ed, 20). Being familiar with these principles will potentially go a long way in supporting and defending the chosen methodology for any given medical IR evaluation. All IR reports should be divided into three main sections: clinical evaluation, analysis of the findings, and discussion. These three sections are required to have specific subsections, such as patient history and a record review, that cannot be omitted if the report is to be in keeping with AMA Guides methodology. Finally, to obtain the highest level of competency, the rating physician should be familiar with jurisdictional requirements that effectively supplant AMA Guides methodology.
