BACKGROUND: The commencement of new academic cycle in July is presumed to be 
associated with poor patient outcomes, although supportive evidence is limited 
for cardiac surgery patients. We sought to determine if the new academic cycle 
affected the outcomes of patients undergoing Coronary Artery Bypass Grafting.
METHODS: A retrospective analysis was performed on 10-year nationwide 
in-hospital data from 1998-2007. Only patients who underwent CABG in the first 
and final academic 3-month calendar quarter were included. Generalized 
multivariate regression was used to assess indicators of hospital quality of 
care such as risk-adjusted mortality, total complications and "failure to 
rescue" (FTOR) - defined as death after a complication.
RESULTS: Of the 1,056,865 CABG operations performed in the selected calendar 
quarters, 698,942 were at teaching hospitals. The risk-adjusted mortality, 
complications and FTOR were higher in the beginning of the academic year [Odds 
ratio = 1.14, 1.04 and 1.19 respectively; p < 0.001 for all] irrespective of 
teaching status. However, teaching status was associated with lower mortality 
(OR 0.9) despite a higher complication rate (OR 1.02); [p < 0.05 for both]. The 
July Effect thus contributed to only a 2.4% higher FTOR in teaching hospitals 
compared to 19% in non teaching hospitals.
CONCLUSIONS: The July Effect is reflective of an overall increase in morbidity 
in all hospitals at the beginning of the academic cycle and it had a pronounced 
effect in non-teaching hospitals. Teaching hospitals were associated with lower 
mortality despite higher complication rates in the beginning of the academic 
cycle compared to non-teaching hospitals. The July effect thus cannot be 
attributed to presence of trainees alone.
ULTRAMINI ABSTRACT: This study compares the July effect in teaching and 
non-teaching hospitals and demonstrates that this effect is not unique to 
teaching hospitals for CABG patients. In fact, teaching hospitals have somewhat 
better outcomes at the beginning of the academic cycle and the July effect is a 
much broader seasonal variation.