Multicenter Study of a Risk Prediction Model for Critically Ill Children at High-Risk for Hospital-Acquired Venous Thromboembolism: Findings from the Children's Hospital-Acquired Thrombosis (CHAT) Consortium

Introduction: Critically ill children are at high-risk of developing a hospital-acquired venous thromboembolism (HA-VTE) as well as being at an increased risk for bleeding. To better understand which subset of children may benefit from thromboprophylaxis measures, (without contraindications for potential associated hemorrhagic complications), the Children's Hospital Acquired Thrombosis (CHAT) Consortium previously derived a HA-VTE risk assessment model (RAM) for critically ill children from 8 centers. This RAM included five variables: (1) immobility defined using a Braden score ≤2, (2) length of hospitalization prior to PICU admission, (3) central venous catheterization, (4) presence of congenital heart disease (CHD) and (5) history of autoimmune/inflammatory disorder or infection. For this study we aimed to externally evaluate our previous HA-VTE RAM in critically ill children in an independent cohort via the CHAT Consortium. Methods: Critically ill children aged 0-21 years admitted or transferred into a pediatric intensive care unit (PICU) at 32 U.S. centers were randomly selected to be enrolled in the study. Participants with a HA-VTE at admission or cardiac surgery within 2 weeks of PICU admission/transfer were excluded. Participants were prospectively followed via chart review for the development of a HA-VTE throughout their hospitalization and up to 30 days post discharge. Twenty-one variables that had been evaluated in univariate analyses from the previously-reported ICU-RAM derivation study were again analyzed in the present prospective cohort via univariate logistic regression. Variables with P-value of