| Medical permanent impairment ratings deal only with the physical impact of injury
to the body and the resulting functional limitations.
This is not the same as the vocational effect of the injury.
Medical impairment ratings cannot be translated directly into
“vocational impairment ratings†or into loss of lifetime income.
The issues are different. The Guides to the Evaluation of
Permanent Impairment, Fifth Edition (AMA Press, 2001) defines
impairment as “a loss, loss of use, or derangement of any body part,
organ system, or organ function.†(page
2) It also distinguishes
impairment from disability, which is defined in the publication as “An
alteration of an individual’s capacity to meet personal, social, or
occupational demands or statutory or regulatory requirements because of an
impairment.†(page 8)
Allowing the Guides to further
speak for itself: “Impairment
ratings were designed to reflect functional limitations and not
disability. The whole person
impairment percentages listed in the Guides estimate the impact of
the impairment on the individual’s overall ability to perform activities
of daily living, excluding work.â€
(page 4; emphasis in original)“The Guides is not intended to be used for direct estimates of work
disability. Impairment
percentages derived according to the Guides criteria do not measure
work disability. Therefore,
it is inappropriate to use the Guides’ criteria or ratings to
make direct estimates of work disability.â€
(page 9)
This is very clear. When
assessing the vocational loss due to injury, many factors other than the
purely physical ones must be considered, such as the person’s age,
education, gender, and work history.
The medical impairment rating has limited use. |