Impairment Rating

An impairment rating is a doctor's measurement of how much a disease or injury has reduced a person's body function, usually expressed as a class or a percentage of the whole person. For lung disease it rests mainly on breathing tests. Workers' compensation systems and some other benefit programs use it to decide how much is paid.

Origin

The American Medical Association began publishing guidance on rating permanent impairment in the late 1950s and issued the first book edition of its Guides to the Evaluation of Permanent Impairment in 1971. The Guides have been revised many times since, and different states and programs require different editions.

Significance in Asbestos Context

For a person with asbestosis or pleural disease, the impairment rating can decide the size of a workers' compensation or other disability award. Under the AMA Guides, respiratory impairment is placed in classes, from no impairment to severe, mainly by comparing FVC, FEV1 and DLCO (and sometimes exercise testing) to predicted values. Two people with the same scarring on X-ray can receive very different ratings if their breathing tests differ, and a rating can change as the disease progresses. Impairment is not the same as disability: impairment is the medical loss of function, while disability depends also on the person's job, age and training. Asbestos trusts generally use their own medical criteria rather than AMA classes, and a court case does not require a rating, but evidence of impairment can still affect what a claim is worth. Which edition of the Guides applies, and how it is used, varies from state to state and program to program.

Example Sentence

After his pulmonary function tests, the examining physician assigned him a Class 2 respiratory impairment under the AMA Guides for his workers' compensation claim.

Related Terms

Pulmonary Function Test (PFT), Workers’ Compensation, Asbestosis, Diffusing Capacity (DLCO), FVC, Restrictive Lung Disease, Occupational Disease Act

Notes

• Ask which edition of the AMA Guides your state or program uses; the edition can change the result.
• Bring your most recent breathing tests to any rating exam, and tell the examiner about symptoms on exertion.
• If your breathing gets worse, ask whether a new rating can be requested.