The July Effect on Mortality, Hospital Length of Stay, and Time to Colonoscopy Among Patients Presenting to Teaching Hospitals With LGIB in the United States.

Background and aim: The "July effect" refers to increased morbidity and mortality observed when new medical trainees start at teaching hospitals in July. This phenomenon has been noted in various conditions but has not been extensively studied in lower gastrointestinal bleeding (LGIB). LGIB accounts for 20% to 30% of major gastrointestinal bleeding admissions, with a mortality rate of 2% to 4%. This study aimed to assess the impact of the "July effect" on clinical outcomes for patients with LGIB admitted to teaching hospitals in the United States from 2016 to 2020.

Methods: This retrospective cohort study analyzed data from the Nationwide Inpatient Sample (2016 to 2020). The primary outcomes were inpatient mortality, hospital length of stay (LOS), and delays in early colonoscopy, defined as more than 24 hours from admission. The key variable was the month of admission, categorized into pre-July (May and June) and July effect (July and August) periods. Survey-weighted multivariable logistic and Poisson regression models were used to evaluate the month of admission's impact on outcomes.

Results: The study included 27,425 admissions, with 13,746 (50.1%) in May and June and 13,679 (49.9%) in July and August. Less than two-thirds (59.2%) of LGIB admissions received a colonoscopy during hospitalization. Among the 15,708 patients who underwent colonoscopy within 7 days of admission, 40.8% had an early colonoscopy (within 24 h). The overall mean hospital LOS was 4.4 days, with an in-hospital mortality rate of 1%. There was no significant "July effect" on delays in early colonoscopy [adjusted odds ratio (aOR) 1.06, 95% CI (0.99, 1.13)], hospital LOS [adjusted incidence rate ratio (aIRR) 1.02, 95% CI (1.00, 1.04)], or in-hospital mortality [aOR 1.17, 95% CI (0.91, 1.50)].

Conclusion: The study found no evidence of a "July effect" on in-hospital mortality, LOS, or delays in early colonoscopy for LGIB patients. Despite the influx of new trainees in July, patient care for LGIB in teaching hospitals seems consistent, indicating that current protocols and supervision effectively mitigate risks. Further research is needed to explore other factors influencing LGIB outcomes and overall patient care during this period.