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.
Method: 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.