title: Retention of basic science information by senior medical students.
abstract: BACKGROUND
  Studies of retention of basic science information have commonly demonstrated a knowledge decline as students progress through medical education. This study examined item characteristics influencing patterns of retention.
  
  
  METHODS
  A large content and statistically representative sample of basic science items from 2004-2005 forms of United States Medical Licensing Examination (USMLE) Step 1 was included in unscored sections of 2004-2005 USMLE Step 2 Clinical Knowledge (CK) test forms, and the performance of 15,000+ first-time examinees from U.S. and Canadian schools was analyzed to identify item characteristics affecting retention.
  
  
  RESULTS
  Across the 502 study items, the mean item difficulty on Step 1 was 76.1%; on Step 2 CK, this value declined to 69.7%. Performance declines were largest in Biochemistry (17.5%) and Microbiology (12.6%). Improvement was only observed for Behavioral Sciences items (8.7%).
  
  
  CONCLUSIONS
  Shifts in examinee performance in this study were similar to those observed in previous research, although the magnitude of the overall decline was somewhat larger.
authors.affiliation: Test Development Associate II, National Board of Medical Examiners, 3750 Market Street, Philadelphia, PA 19104, USA. lling@nbme.org
authors.forename: Yu
authors.initials: Y
authors.lastname: Ling
authors.forename: David B
authors.initials: DB
authors.lastname: Swanson
authors.forename: Kathy
authors.initials: K
authors.lastname: Holtzman
authors.forename: S Deniz
authors.initials: SD
authors.lastname: Bucak
mesh_terms: D001690:Biological Science Disciplines / Q000193:education*; D002170:Canada; D015331:Cohort Studies; D004504:Education, Medical, Undergraduate; D004521:Educational Measurement; D006801:Humans; D008007:Licensure, Medical; D012153:Retention, Psychology; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States