A Nationwide Study of the "July Effect" Concerning Postpartum Hemorrhage and Its Risk Factors at Teaching Hospitals across the United States.

Objective To assess the "July effect" and the risk of postpartum hemorrhage (PPH) and its risk factors across the U.S. teaching hospitals. Method This study used the 2018 Nationwide Inpatient Sample (NIS) and included 2,056,359 of 2,879,924 single live-birth hospitalizations with low-risk pregnancies across the U.S. teaching hospitals. The International Classification of Diseases, Tenth Revision (ICD-10) from the American Academy of Professional Coders (AAPC) medical coding was used to identify PPH and other study variables. Multivariable logistic regression models were used to compare the adjusted odds of PPH risk in the first and second quarters of the academic year vs. the second half of the academic year. Results Postpartum hemorrhage occurred in approximately 4.19% of the sample. We observed an increase in the adjusted odds of PPH during July through September (adjusted odds ratios (AOR), 1.05; confidence interval (CI), 1.02-1.10) and October through December (AOR, 1.07; CI, 1.04-1.12) compared to the second half of the academic year (January to June). Conclusions This study showed a significant "July effect" concerning PPH. However, given the mixed results concerning maternal outcomes at the time of childbirth other than PPH, more research is needed to investigate the "July effect" on the outcomes of the third stage of labor. This study's findings have important implications for patient safety interventions concerning MCH.