Abstract
The AMA Guides to the Evaluation of Permanent Impairment, (AMA Guides), Sixth Edition, is the recognized international standard for assessing impairment. The National Council on Compensation Insurance (NCCI) conducted a comparative study to examine the effects on impairment ratings in three states that have switched from the fifth to the sixth edition. The purpose and objectives of this article are as follows: 1) to provide a brief review of the conceptual framework and terminology of disablement and of the current model of disability in the AMA Guides and also to underscore the importance of the construct of medical impairment to compensation schemes within workers' compensation and other disability systems; 2) to examine the AMA Guides in terms of its origin, purpose, distribution, applications, and misapplications; 3) to examine the changes in the sixth edition in terms of efforts to direct change and improve upon the AMA Guides; 4) to examine the merits and shortcomings of the NCCI study and its conclusions within a broader context of inherent sources of variance in impairment ratings, as well as the content validity, reliability, and reproducibility of the ratings themselves; 5) to provide recommendations regarding the implications of this study for the use of the sixth and earlier editions of the AMA Guides, and to suggest new directions for much needed critical research.
