title: COMLEX-1 and USMLE-1 are not interchangeable examinations.
abstract: OBJECTIVE
  Osteopathic medical students must take the Comprehensive Osteopathic Medical Licensing Examination (COMLEX)-USA series of examinations, but not the United States Medical Licensing Examination (USMLE-1) series. Few data are available describing the comparability of the two tests. This study sought to determine if COMLEX-1 scores could predict USMLE-1 scores among osteopathic medical students applying to an emergency medicine (EM) residency and to determine if the scores are interchangeable.
  
  
  METHODS
  This was a retrospective analysis of osteopathic medical students applying to an EM residency program in the 2005-2006 and 2006-2007 application seasons. Students were included if they took both the COMLEX-1 and the USMLE-1 examinations. Linear regression was performed and a Bland-Altman plot of the standardized mean scores of each test was created.
  
  
  RESULTS
  Ninety students were included. The mean (+/- standard deviation [SD]) COMLEX-1 score was 559.5 (+/-68.6), and the mean (+/-SD) USMLE-1 score was 207.6 (+/-15.5). The correlation was 0.79, with an R(2) of 62.3%. The Bland-Altman plot showed a mean difference between the standardized scores of 0, with 95% confidence intervals (CIs) of )1.28 to +1.28 standard normal units. Limitations include that this was a single center study, and only students who took both tests could be studied.
  
  
  CONCLUSIONS
  COMLEX-1 scores predict only 62.3% of the variance in USMLE-1 scores, and the scores are not interchangeable.
authors.affiliation: Department of Emergency Medicine, Maricopa Medical Center, Phoenix, AZ, USA. sarkoj@cox.net
authors.forename: John
authors.initials: J
authors.lastname: Sarko
authors.forename: Elena
authors.initials: E
authors.lastname: Svoren
authors.forename: Eric
authors.initials: E
authors.lastname: Katz
mesh_terms: D004521:Educational Measurement / Q000592:standards*; D004635:Emergency Medicine / Q000193:education*; D006801:Humans; D007396:Internship and Residency; D010021:Osteopathic Medicine / Q000193:education*; D012189:Retrospective Studies