Patel B, Buschbacher R, Crawford J: National variability in permanent partial impairment ratings. Am J Phys Med Rehabil 2003;82:302–306.
Objective: To evaluate the variability in permanent partial impairment ratings of three different clinical vignettes by physiatrists throughout the United States with regard to location in the country, years of experience, and type of practice.
Design: Participants were asked to fill out a questionnaire requesting their state of practice, number of years in practice, scope of their practice, and percentage of their time devoted to worker’s compensation cases. They were also given three clinical scenarios and were asked for the diagnosis of each, along with an impairment rating and how that rating was obtained.
Results: The range of impairment ratings for the case of radiculopathy was 0–14%. The range for the case of radial neuropathy was 3–60%. The range for the total hip replacement case was 8–100%. The responses did not correlate with region, years of experience, or type of practice except in the first case, in which a trend was noted that the younger respondents gave lower ratings. Participants used different sources for obtaining their results, which included the third, fourth, or fifth edition of the American Medical Association’s guides to impairment. Some used their state guides, whereas others used their clinical judgment.
Conclusion: There is a great deal of variability of permanent partial impairment ratings throughout the country; several different sources are used to determine ratings.