Dramatic Increase in Venous Thromboembolism in Children's Hospitals in the United States From 2001 to 2007

OBJECTIVES: The goals were to determine whether there has been an increase in the rate of venous thromboembolism (VTE) in pediatric tertiary care hospitals and to evaluate the use of anticoagulants in the treatment of hospitalized pediatric patients with VTE. METHODS: A retrospective cohort study of patients < 18 years of age who were discharged from 35 to 40 children's hospitals (depending on the year) across the United States in 2001-2007 was performed. By using the Pediatric Health Information System administrative database, cases were assessed for discharge diagnosis codes for VTE; the use of anticoagulants was assessed by using patient-specific pharmacy files. RESULTS: During the 7-year study period, in which 11 337 hospitalized patients were diagnosed with VTE, the annual rate of VTE increased by 70%, from 34 to 58 cases per 10 000 hospital admissions (P < .001). This increase was observed in neonates, infants, children, and adolescents. The majority (63%) of children with VTE had >= 1 coexisting chronic complex medical condition. Pediatric malignancy was the medical comorbid condition associated most strongly with recurrent VTE (P < .001). The proportion of children with VTE who were treated with enoxaparin increased from 29% to 49% during this time period (P < .001); the use of warfarin decreased slightly from 11.4% to 9.6% (P = .02). Increasing age was associated with increased likelihood of patients with VTE being treated with either enoxaparin or warfarin. CONCLUSION: This multicenter study demonstrates a dramatic increase in the diagnosis of VTE at children's hospitals from 2001 to 2007. Pediatrics 2009; 124: 1001-1008