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BY-NC-ND 4.0 license Open Access Published by De Gruyter October 1, 2010

New COMLEX-USA-to-USMLE Conversion Formula Needed

John R. Gimpel

To the Editor:

In a July letter to the editor, Sahil P. Parikh, DO, and Carly A. Shiembob, DO,1 thoughtfully asked the following question:

How does a director of an ACGME [Accreditation Council for Graduate Medical Education] residency program compare an osteopathic medical student's COMLEX-USA [Comprehensive Osteopathic Medical Licensing Examination-USA] score with an allopathic medical student's USMLE [United States Medical Licensing Examination] score?

After citing a formula for estimating USMLE scores from COMLEX-USA scores—described in the September 2006 JAOA by Philip C. Slocum, DO, and Janet S. Louder2—they characterize this formula as ineffective. Drs Parikh and Shiembob1 conclude, rather than making an effort to get ACGME programs to accept COMLEX-USA results, “we believe it is more important for the osteopathic medical profession to develop a formula for examination score conversion that will more accurately reflect the qualifications of osteopathic medical students.”

As president and chief executive officer of the National Board of Osteopathic Medical Examiners (NBOME)—the creators and sole administrators of the COMLEX-USA series of examinations—I am happy to respond to the letter by Drs Parikh and Shiembob.1

First, I would like to highlight the response to Drs Parikh's and Shiembob's letter1 written by Dr Slocum,3 which also appeared in the July issue. In his response, Dr Slocum3 acknowledges that the statistical analysis conducted 5 years ago2 is no longer valid because of changes in both examinations. I would add that the 2006 Slocum and Louder study2 was based on a group of students from a single osteopathic medical school, and the sample size was small. The demographic characteristics of the student sample were, therefore, not representative of the total pool of osteopathic medical students in the United States. In other words, although the statistical relationship between the USMLE and COMLEX-USA examinations may have been true for that particular school in 2006, it would not necessarily have been true for the national group of osteopathic medical students.

From the NBOME's perspective, the more important point is contained in the second part of Dr Slocum's response,3 in which he notes the osteopathic distinctiveness of the COMLEX-USA examination series. We at the NBOME understand the desire for a “conversion formula,” and we are aware of the challenges faced by osteopathic medical students when applying to ACGME-accredited residency programs. However, because of the different natures of the examinations, it is not possible—or even desirable—to make a direct numerical comparison between the scores of the COMLEX-USA examination series and those of the USMLE.

The osteopathic medical profession honors its contract with the public by ensuring osteopathic physicians are licensed based on results of the COMLEX-USA, which is designed for the practice of osteopathic medicine and validated for that distinct purpose. Only the COMLEX-USA series assesses the skills and philosophy unique to the osteopathic medical profession.

Osteopathic medical students and residents train for the practice of osteopathic medicine. The curriculum of every osteopathic medical school incorporates distinctive osteopathic principles and prepares students for medical practice as osteopathic physicians. The COMLEX-USA incorporates these distinctive osteopathic principles, and it is constructed and validated based on practice patterns that are unique to DOs, including the use of osteopathic manipulative treatment. By contrast, the USMLE does not meet these criteria for assessing osteopathic medical students, and it does not test for osteopathic principles or osteopathic manipulative treatment.

Residency programs consider a wide variety of important factors in determining which applicants to interview and accept. Examination scores are only one of these factors. Although neither the COMLEX-USA nor the USMLE is designed primarily for the purpose of evaluating residency program applicants—they are both designed primarily for initial licensure of physicians—residency program directors do commonly consider test scores in evaluating applicants. When it comes to examinations, the NBOME encourages residency program directors to consider the COMLEX-USA series as the valid and most appropriate assessment tool for osteopathic medical students.

The NBOME has made many efforts over the years to facilitate both osteopathic and allopathic residency program directors' understanding of COMLEX-USA scoring. Specifically, the NBOME reports a 2-digit standard score on all Electronic Residency Application Service requests for COMLEX-USA scores-just as the National Board of Medical Examiners does with USMLE scores. The NBOME's Web site ( features a conversion tool that allows interested parties to obtain percentile scores for the COMLEX-USA.

Despite these efforts, we recognize that more information and education are needed, and we are committed to residency program director outreach as a top priority. The NBOME is actively seeking opportunities to convey the information I have outlined in this letter directly to ACGME residency program directors—particularly those with programs to which large numbers of osteopathic medical students are applying. Our goal is to increase program directors' understanding of the COMLEX-USA examination series, including its content, development, validity, and scoring. We anticipate that improved understanding will allow program directors to recognize the COMLEX-USA as an entity unto itself (rather than something requiring comparison to the USMLE) and as the most appropriate tool with which to evaluate osteopathic medical students.

I would like to thank Drs Parikh and Shiembob1 for their considered efforts in testing the equations reported by Dr Slocum2 and for the time they spent addressing this important matter. I would also like to thank Dr Slocum3 for his response to the letter by Drs Parikh and Shiembob.1 We at the NBOME are taking steps to mitigate the challenges osteopathic medical students sometimes face with respect to COMLEX-USA scores when applying to ACGME-accredited residency programs.

At the same time, I would like to call on all members of the osteopathic medical profession to join me in repeating and reinforcing our fundamental conviction—the COMLEX-USA series of examinations is the valid and most appropriate evaluation tool for osteopathic medical students. I welcome further ideas and suggestions on this matter.

1 Parikh SP, Shiembob CA. New COMLEX-USA-to-USMLE conversion formula needed [letter]. J Am Osteopath Assoc. 2010;110(7):400-401. Accessed August 31, 2010.Search in Google Scholar

2 Slocum PC, Louder JS. How to predict USMLE scores from COMLEX-USA scores: a guide for directors of ACGME-accredited residency programs. J Am Osteopath Assoc. 2006;106(9):568-569. Accessed August 31, 2010.Search in Google Scholar

3 Slocum PC. Response [letter]. J Am Osteopath Assoc. 2010;110(7):401. Accessed August 31, 2010.Search in Google Scholar

Published Online: 2010-10-01
Published in Print: 2010-10-01

The American Osteopathic Association

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