The approach of the fourth edition of the AMA Guides in evaluating “permanent impairment” is both careless and cavalier. The following are numerous examples:

  • “…two measurements by the same examiner and involving a patient or a patient’s function may be expected to lie within 10% of each other” [page 9].  No comment regarding measurements of the same patient at different times and by different assessors, the scenario seen in multiple assessments of patients in the context of multidisciplinary plaintiff vs defence medical insurance purposes  is provided.
  • “The individual with one kidney, regardless of cause, should be considered to have a 10% whole-person impairment because of the loss of an essential organ” [page 250].  No rating for loss of a spleen is allowed however in spite of significant future risk to health and life.:  [Example 2, page 205].
  • “If an ocular or adnexal disturbance or deformity interferes with visual function and is not reflected in diminished visual acuity, decreased visual fields, or ocular motility with diplopia, the significance of the disturbance or deformity should be evaluated by the examining physician. In that situation, the physician may (emphasis added) combine an additional 5% to 10% impairment”. [page 209].
  • “Tinnitus in the presence of unilateral hearing loss may impair speech discrimination and adversely influence the ability to carry out daily activities. Therefore, up to 5% may be added because of tinnitus to an impairment estimate for severe unilateral hearing loss.” (Nervous System, Chapter 4, page 145] BUT “Tinnitus in the presence of unilateral hearing loss may impair speech discrimination; therefore, an impairment percentage up to 5% may be added to the impairment for unilateral hearing loss.” [Ear Nose and Throat, Chapter 9, Page 224].  The term “severe” hearing loss is left out here.
  • “An impairment estimate for anosmia or parosmia, which should be given only if the anosmia interferes significantly with daily activities, would be combined with any other permanent impairment (Combined Values Chart, p. 322). The maximum impairment from anosmia is 5%.” [page 144].   What does “interferes significantly with daily activities” mean?  Would this imply that the rating would only apply to a professional chef?  Or a firefighter? 
  • “Persistent vegetative state, or irreversible coma requiring total medical support” is rated at 50-90% WPI [Nervous System, Chapter 4, Table 4, page 142].  How can a person in an irreversible coma requiring total medical support be rated a less than catastrophic?  Does this mean the 50% WPI and 90% WPI are/can be considered as equivalent levels of impairment?
  • Mild mental status impairment is defined as: “Impairment exists, but ability remains to perform satisfactorily most activities of daily living” [Nervous System, Chapter 4, Table 2, page 142]  None of the terms in this vague description are further defined               AND
  • Moderate mental status impairment under the same table is defined as “Impairment requires direction and supervision of daily living activities”.  “Supervision” is not defined. Does this mean, say, in an office worker as someone checking their work, or is it a requirement to have attendant care?