P4.050: Vitamin K Deficiency Bleeding in the United States:A Retrospective Cohort Study of the Pediatric Health Information System Database​

Background: Vitamin K Deficiency Bleeding (VKDB) is a potentially severe and preventable coagulopathy in newborns with early, classic, and late subtypes. Intramuscular Vitamin K (VK) in the newborn period prophylaxes against VKDB and is universally recommended by the AAP. However, VK refusal rates may be increasing in the U.S. This study aims to describe the incidence of VKDB in a large national database and identify any changes in demographic and clinical characteristics over time.

Methods: We performed a retrospective cohort study of inpatients 6 months or younger in a PHIS-network hospital 2016-2024 with the diagnosis of VKDB, Hemorrhagic Disease of the Newborn (HDN), Deficiency of coagulation factor due to Vitamin K deficiency, or Vitamin K deficiency. Subjects were excluded if they had a concurrent diagnosis of congenital factor deficiency, suggesting an alternate diagnosis from VKDB. Linear regression was performed to assess the trend of annual admission count over time. The Cochrane Armitage trend test assessed for linear trends in the proportion of categorical variables over time.

Results: Nine hundred twenty-nine encounters for unique patients from 34 PHIS hospitals met the inclusion criteria. There were an average of 103 annual admissions for VKDB (21% early-onset, 9% classic, 70% late-onset). Rates of ICU admission, blood- and platelet-transfusion, mechanical ventilation, neurosurgical procedures, hepatic disease diagnosis, and immunization refusal diagnosis are summarized across disease subtypes. There was a significant increase in late-onset VKDB admissions over time (p = 0.028), but no appreciable change in admissions for early-onset and classic forms. There was a significant positive trend in the proportion of patients with a diagnosis related to immunization refusal (p < 0.001); other clinical characteristics were stable over time.

Conclusion: This study is the first to evaluate the epidemiology and clinical characteristics of VKDB in a large national database. VKDB remains a serious disease with significant infant morbidity and mortality, as reflected by the high rates of ICU admission, mechanical ventilation, intracranial hemorrhage, and mortality seen in our cohort. The incidence of this disease increased modestly but significantly over the study period. While this study is not designed to make a causal inference as to the rise in admissions, it is noteworthy that the diagnosis of immunization refusal, which prior work has shown is associated with VK refusal, was prevalent among the late-onset subtype and had increased both significantly and dramatically across the study period. More work is needed to understand the prevalence of VK refusal at birth as well as the risk of VKDB among infants who do not receive VK at birth.