A nationwide retrospective study of the July effect on nonvariceal upper GI bleeding outcomes in teaching hospitals in the United States

BACKGROUND: "July effect" also known as "July phenomenon" are adverse patient outcomes related to the changeover of medical residents in teaching hospitals in the United States at a particular time of the year. This study aims to explore this phenomenon on hospital outcomes among patients with nonvariceal upper gastrointestinal bleeding (UGIB). METHODS: The National Inpatient Sample data from Jan 1, 2016, to Dec. 31, 2020, was used. Patients admitted in teaching hospitals between May and August were stratified patients into two groups; May & June; as (Non-July Effect), July & August as (July Effect). The study involved a comprehensive assessment and comparison of various clinical outcomes, including the likelihood of mortality, length of hospital stay, and the utilization and timing of esophagogastroduodenoscopy (EGD). These analyses were conducted while controlling factors such as socio-demographic variables, hospital characteristics, and associated comorbidities to ensure accurate and meaningful results. RESULTS: A total of 53,710 patients had non-variceal UGIB. There is no significant difference in Mortality risk (aOR = 1.10, 95% CI: 0.86-1.40, p = 0.4406), Length of hospitalization (0.98, 0.91-1.05, p = 0.5410), EGD (1.04, 0.94-1.32, p = 0.4412), and Early EGD (0.97, 0.80-1.19, p = 0.7759) between the July effect and non-July effect groups. CONCLUSIONS: The analysis reveals no significant differences in mortality rates, length of hospitalization, or endoscopy and its timing among patients with UGIB during the July effect compared to those not affected by this phenomenon. Our study corroborates previous research on the July phenomenon while also exploring this phenomenon in upper gastrointestinal bleeding.