title: The July effect and cardiac surgery: the effect of the beginning of the academic cycle on outcomes.
abstract: 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.
authors.affiliation: Division of Cardiology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Amandeep S
authors.initials: AS
authors.lastname: Dhaliwal
authors.forename: Danny
authors.initials: D
authors.lastname: Chu
authors.forename: Anita
authors.initials: A
authors.lastname: Deswal
authors.forename: Biykem
authors.initials: B
authors.lastname: Bozkurt
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Coselli
authors.forename: Scott A
authors.initials: SA
authors.lastname: LeMaire
authors.forename: Joseph
authors.initials: J
authors.lastname: Huh
authors.forename: Faisal G
authors.initials: FG
authors.lastname: Bakaeen
mesh_terms: D000046:Academic Medical Centers; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D011787:Quality of Health Care; D012307:Risk Factors; D012621:Seasons; D013781:Texas / Q000453:epidemiology