The July effect: impact of the beginning of the academic cycle on cardiac surgical outcomes in a cohort of 70,616 patients.
BACKGROUND
Because surgical residents' level of experience may be at its nadir early in the academic year, academic seasonality-or the "July effect"-could affect cardiac surgical outcomes.


METHODS
Prospectively collected data from the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Program were used to identify 70,616 consecutive cardiac surgical procedures performed between October 1997 and October 2007. Morbidity and mortality rates were compared between early (July 1 to August 31, n = 11,975) and late (September 1 to June 30, n = 58,641) periods in the academic year. A prediction model was constructed by using stepwise logistic regression modeling.


RESULTS
The two patient groups had similar demographic and risk variables. Isolated coronary artery bypass grafting accounted for 76.7% of early-period procedures and 75.8% of later-period procedures (p = 0.03). Morbidity rates did not differ significantly between the early (14.0%) and later periods (14.2%; odds ratio [OR], 1.01; 95% confidence interval [CI], 0.96 to 1.07; p = 0.67) and operative mortality was similar, 3.7% vs 3.9% (OR, 0.99; 95% CI, 0.89 to 1.11; p = 0.90). The early portion of the year was associated with longer cardiac ischemia times (84 +/- 40 vs 83 +/- 42 minutes), cardiopulmonary bypass times (126 +/-52 vs 124 +/-56 minutes), and total surgical times (295 +/- 90 vs 288 +/- 90 minutes; p < 0.05 for all).


CONCLUSIONS
The early part of the academic year was associated with slightly longer operative times; however, risk-adjusted outcomes were similar in both periods. This finding should lessen concerns about the quality of cardiac surgical care at the beginning of the academic year.
Bakaeen
Faisal G
FG
Michael E DeBakey Department of Surgery, Division of Cardiothoracic Surgery, Baylor College of Medicine, Houston, Texas 77030, USA. fbakaeen@bcm.edu
Huh
Joseph
J
LeMaire
Scott A
SA
Coselli
Joseph S
JS
Sansgiry
Shubhada
S
Atluri
Prasad V
PV
Chu
Danny
D
D000046:Academic Medical Centers; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000193:education / Q000401:mortality*; D002983:Clinical Competence; D004503:Education, Medical, Graduate; D005260:Female; D019538:Health Care Surveys; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007396:Internship and Residency; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D011336:Probability; D012042:Registries; D012308:Risk Management; D012621:Seasons; D016019:Survival Analysis; D013997:Time Factors