Does the “July effect” of new trainees at teaching hospitals impact outcomes for patients hospitalized with heart failure? Real-world analyses of more than half a million US admissions

Introduction: The "July effect" refers to the potential of adverse clinical outcomes related to the annual turnover of trainees. We investigated whether this impacts inpatient heart failure (HF) outcomes. Methods: Data from all adults (≥18 years) admitted with a primary diagnosis of HF at US teaching hospitals from the 2012-2014 National Inpatient Sample were analyzed. Non-teaching hospital admissions were excluded. The primary outcome was in-hospital mortality. Secondary metrics included hospital length of stay (LOS) and total cost adjusted for inflation. Logistic and linear regression models were used to adjust for confounders. Admissions were classified into 4 quarters (Q1-Q4), based on the academic calendar. Q1 and Q4 were designated to assess the effect of novice (July effect) versus experienced trainees, respectively. Results: There were 699,675 HF admissions during Q1 and Q4 in the study period. Mean age was 71 ± 15 years and 48% were females. There were 20,270 in-hospital deaths, with no difference between Q1 and Q4; crude odds ratio (OR) 1.00, 95% confidence interval (CI) 0.94-1.07, p = 0.95. After risk adjustment, there was no in-hospital mortality difference between Q1 and Q4 admissions; adjusted OR 0.96, 95% CI 0.89-1.03, p = 0.23. There was no difference in hospital LOS or total cost; 5.8 versus 5.8 days, p = 0.66 and $13,755 versus $13,586, p = 0.46, in Q1 and Q4, respectively. Conclusions: In this nationally representative sample, there was no evidence of a "July effect" on inpatient HF outcomes in the US. This suggests that HF patients should not delay seeking care during trainee transitions at teaching hospitals.