di , 20/10/2023

Hospital-acquired venous thromboembolism is a serious condition that can lead to complications and mortality in pediatric patients. Therefore, there is a need to identify effective strategies for its prevention.

A recent study conducted at Monroe Carell Jr Children’s Hospital at Vanderbilt aimed to evaluate the effectiveness of an automated prognostic model in preventing hospital-acquired venous thromboembolism (HA-VTE) among hospitalized children and adolescents.

In short, it aimed to determine if an automated prognostic model embedded in the electronic medical record (EMR) could aid in making informed decisions regarding thromboprophylaxis.

The study, titled “Model-Guided Decision-Making for Thromboprophylaxis and Hospital-Acquired Thromboembolic Events Among Hospitalized Children and Adolescents: The CLOT Randomized Clinical Trial,” was published in JAMA Network Open.

Study Design

This was a randomized clinical trial conducted between November 2020 and January 2022 at a single academic children’s hospital. Pediatric patients (aged <22 years) in inpatient status were included and randomly assigned to the control or intervention group.

The trial involved 17,427 pediatric hospitalizations, with patients randomized into control and intervention groups. The prognostic model automatically calculated the HA-VTE probability daily in the intervention group and made this information visible to the hematology research team. Those at elevated risk (predicted probability ≥2.5%) underwent additional medical record review for potential thromboprophylaxis.


The primary outcome of the study was the rate of HA-VTE, while secondary outcomes included rates of prophylactic anticoagulation and anticoagulation-associated bleeding events. The results showed that in the control group, 58 patients (0.7%) developed HA-VTE, compared to 77 patients (0.9%) in the intervention group. However, this difference was not statistically significant.


Main findings:

  • Participants: 17,427 hospitalizations were analyzed, evenly distributed between the control and intervention groups.
  • HA-VTE Rates: 0.7% in the control group and 0.9% in the intervention group developed HA-VTE, a non-statistically significant difference.
  • Thromboprophylaxis Initiation: Recommendations for thromboprophylaxis were followed only 25.8% of the time.
  • Bleeding Events: Minor bleeding events were rare (4.1%) among patients receiving anticoagulation, and no major bleeding events were observed.
  • Model Accuracy: The prognostic model in the control group exhibited high accuracy (C statistic, 0.799).

The study highlights the challenge of implementing preventive measures even with advanced prognostic tools. Clinician hesitancy remains a barrier in reducing HA-VTE rates among hospitalized pediatric patients.

Despite utilizing an accurate HA-VTE prognostic model, primary clinical teams were reluctant to initiate recommended thromboprophylaxis, leading to no significant difference in HA-VTE rates between the control and intervention groups. Further research is necessary to develop better prevention strategies for HA-VTE and address clinician concerns regarding thromboprophylaxis.