The July effect and cardiac surgery: the effect of the beginning of the academic cycle on outcomes

Background The effect of the time of the academic year on cardiac surgical outcomes is unknown. Methods Using prospectively collected data, we identified all (n = 1,673) cardiac surgical procedures performed at our institution between October 1997 and April 2007. Morbidity and mortality rates were compared between 2 periods of the academic year, one early (July 1–August 31, n = 242) and one later in the year (September 1–June 30, n = 1,431). A prediction model was constructed by using stepwise logistic regression modeling. Results Morbidity rates did not differ significantly between the early (12.8%) and later periods (15.4%) (odds ratio [OR], 0.83; 95% confidence interval [CI], 0.54–1.28; P = 0.3). Additionally, there was no significant difference in operative mortality between the early (1.2%) and later periods (3.5%) (OR, 0.28; 95% CI, 0.07–1.19; P = 0.06). Conclusions The early and later parts of the academic year were associated with similar risk-adjusted outcomes. Further studies are needed to determine whether our findings are applicable to other academic cardiac centers.