Does the NBME Surgery Shelf exam constitute a “double jeopardy” of USMLE Step 1 performance?

Michael S. Ryan, Jorie Colbert-Getz, Salem N. Glenn, Joel D. Browning, Rahul J. Anand

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Background Scores from the NBME Subject Examination in Surgery (Surgery Shelf) positively correlate with United States Medical Licensing Examination Step 1 (Step 1). Based on this relationship, the authors evaluated the predictive value of Step 1 on the Surgery Shelf. Methods Surgery Shelf standard scores were substituted for Step 1 standard scores for 395 students in 2012–2014 at one medical school. Linear regression was used to determine how well Step 1 scores predicted Surgery Shelf scores. Percent match between original (with Shelf) and modified (with Step 1) clerkship grades were computed. Results Step 1 scores significantly predicted Surgery Shelf scores, R2 = 0.42, P < 0.001. For every point increase in Step 1, a Surgery Shelf score increased by 0.30 points. Seventy-seven percent of original grades matched the modified grades. Conclusion Replacing Surgery Shelf scores with Step 1 scores did not have an effect on the majority of final clerkship grades. This observation raises concern over use of Surgery Shelf scores as a measure of knowledge obtained during the Surgery clerkship.

Original languageEnglish (US)
Pages (from-to)325-329
Number of pages5
JournalAmerican Journal of Surgery
Issue number2
StatePublished - Feb 1 2017
Externally publishedYes


  • Surgery clerkship
  • Surgery Shelf exam
  • USMLE Step 1 exam

ASJC Scopus subject areas

  • Surgery


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