Hospital-associated venous thromboembolism in children: incidence and clinical characteristics

To determine incidence and clinical characteristics of hospital-associated venous thromboembolism (VTE) in pediatric patients.

A retrospective analysis of patients with hospital-associated VTE at the Johns Hopkins Hospital from 1994 to 2009 was performed. Clinical characteristics of patients aged 21 years and younger who developed VTE symptoms after 2 days of hospitalization or <90 days after hospital discharge were examined. International Classification of Diseases, Ninth Revision codes were used to categorize patients with complex chronic medical conditions and trauma.

There were 270 episodes of hospital-associated VTE in 90,485 admissions (rate 30 per 10,000 admissions). Young adults (18-21 years) and adolescents (14-17 years) had significantly increased rates of VTE compared with children (2-9 years) (incidence rate ratio [IRR] 7.7, 95% CI 5.1-12.0; IRR 4.3, 95% CI 2.7-6.8, respectively). A central venous catheter (CVC) was present in 50% of patients, and a surgical procedure was performed in 45% of patients before VTE diagnosis. For patients without a CVC, trauma was the most common admitting diagnosis. CVC-related VTE was diagnosed most frequently in infants (<1 year old) and in patients with malignancy. Renal and cardiac diseases were associated with the highest rates of VTE (51 and 48 per 10,000, respectively). Rates were significantly higher among those with ≥ 4 medical conditions compared with those with 1 medical condition (IRR 4.0, 95% CI 1.4-8.9).

Older age and multiple medical conditions were associated with increased rates of hospital-associated VTE. These data can contribute to the design of future clinical trials to prevent hospital-associated VTE in high-risk children.