Inpatient Characteristics and Outcomes of Venous Thromboembolism Among Children and Adolescents

Importance: Endogenous venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism (PE), is considered a rare event in pediatric patients, and its health care implications are largely unstudied. However, its burden on the health care system may be disproportionately higher owing to age-specific risk factors. Objective: To evaluate and characterize the inpatient cohort of children and adolescents with VTE and PE. Design, Setting, and Participants: This nationwide cohort study used data on inpatient cases of VTE in Germany (data source: Federal Bureau of Statistics DESTATIS) from 2020 to 2024. Cases younger than 20 years with VTE as the main or secondary diagnosis, as well as a subcohort with PE as the main diagnosis, were analyzed regarding risk profiles, inpatient care, and outcomes stratified by sex and age. Main Outcomes and Measures: Hospital-based incidence of VTE (VTE cases per 10 000 inpatient cases per year) and in-hospital mortality. Results: This study identified 14 108 pediatric inpatient cases of VTE (mean [SD] age, 9.0 [7.3] years; 7201 male [51.0%]), corresponding to a hospital-based incidence of 15.3 per 10 000 pediatric cases per year. A total of 3311 patients with VTE (23.5%), comprising 1361 of 6907 female patients (19.7%) and 1950 of 7201 male patients (27.1%), were infants younger than 1 year. Risk factors for VTE varied, as rates of infection, chronic organ failure, and congenital diseases decreased with increasing patient age, while cancer was most commonly diagnosed among cases aged 5 to 14 years, and thrombophilia remained a relatively constant risk factor across all age groups. PE occurred in 1564 VTE cases (11.1%); among cases whose main diagnosis was PE, 624 of 888 (70.3%) were female. The in-hospital mortality rate in the VTE cohort was 3.7% (522 of 14 108); mortality risk was significantly increased among infants aged 4 years or younger (OR, 3.52 [95% CI, 2.73-4.57]; P < .001). Conclusions and Relevance: This cohort study found a marked inpatient health care and economic burden for VTE among children and adolescents. Mortality risk was significantly increased among infants younger than 1 year. Studies are needed to provide evidence-based support for the safety and effectiveness of medical interventions for children and adolescents with VTE.