Purpose: The Step 2 Clinical Knowledge (CK) examination of the United States Medical Licensing Examination sequence is a requirement for the certification of international medical graduates (IMGs) by the Educational Commission for Foreign Medical Graduates. An association between scores on the test and the quality of care later provided by those who take it is central to its use in certification and licensure. The purpose of this study was to determine whether there is a relationship between scores on Step 2 CK and patient outcomes for IMGs.
Method: This is a retrospective observational study of the 60,958 hospitalizations from 2003 to 2009 in Pennsylvania where the principal diagnosis was acute myocardial infarction or congestive heart failure and the attending physician (N = 2,525) was an IMG who had taken the Step 2 CK. The main measures were the three-digit scores on Step 2 CK and in-hospital mortality.
Results: After adjustment for severity of illness, physician characteristics, and hospital characteristics, performance on Step 2 CK had a statistically significant inverse relationship with mortality. Each additional point on the examination was associated with a 0.2% (95% CI: 0.1%-0.4%) decrease in mortality. The size of the effect is noteworthy, with each standard deviation (roughly 20 points) equivalent to a 4% change in mortality risk.
Conclusions: These findings provide evidence for the validity of Step 2 CK scores. Given the magnitude of its relationship with patient outcomes, the results support the use of the examination as an effective screening strategy for licensure.