Primary thromboprophylaxis in hospitalized children: A multi-center retrospective analysis

Background/objectives: Hospital acquired venous thromboembolism in children is associated with significant morbidity/mortality. Prevention strategies include sequential compression devices and prophylactic anticoagulation but these interventions carry risk and are poorly studied in children. Objectives were to evaluate primary thromboprophylaxis use in hospitalized children over time and the associated bleeding risk.

Materials and methods: Retrospective study of hospitalized patients aged 10-18 years within the Pediatric Health Information System administrative database from January 2008-September 2015. Factors associated with thromboprophylaxis receipt and bleeding were identified using generalized linear mixed effects models.

Results: Of 1,075,383 hospitalizations, 10,544 (1%) received prophylactic enoxaparin and 58,768 (5%) received mechanical compression. Mechanical thromboprophylaxis increased slightly over time (4.3% in 2008, 6.2% in 2015), enoxaparin use did not (0.8% in 2008, 1.2% in 2015). Patients aged 16-18 were more likely than younger children (10-12) to receive pharmacologic (adjusted odds ratio [aOR] 3.1, 95% confidence interval [CI] 2.9-3.3) or mechanical thromboprophylaxis (aOR 2.9, 95% CI 2.9-3). Patients on rehabilitation medical service were more likely to receive prophylactic enoxaparin (aOR 53, 95% CI 44.1-64.5). 5.6% (589/10,544) of patients receiving enoxaparin prophylaxis had bleeding. Thromboprophylaxis use by hospital varied with a range of 0.25-3.3% for enoxaparin and 2-26.2% for mechanical compression.

Conclusion: Thromboprophylaxis is infrequently utilized in hospitalized children. Pharmacologic prophylaxis with enoxaparin remains low and has not substantially increased over time. Significant variability exists across hospitals and services in the administration of both mechanical and pharmacologic thromboprophylaxis highlighting the need for further evidence to standardize practice.