Comparative validation study of risk assessment models for pediatric hospital‐acquired venous thromboembolism

Abstract

Background Risk assessment models (RAMs) have been developed to identify children at high risk of hospital‐acquired venous thromboembolism (HA‐VTE). None have been externally validated nor compared. Objectives The objective was to compare performance of these RAMs by externally validating them using the Children's Hospital‐Acquired Thrombosis (CHAT) Registry, ie, a multicenter database of children with radiographic‐confirmed HA‐VTE and corresponding controls. Patients/Methods Risk assessment models were included if the full logistic regression equation was available and all RAM variables were collected in the CHAT Registry. A random sample of 200 cases and 200 controls was selected. The performance of the RAMs was assessed for discrimination using area under the receiver operating characteristic curves (AUROC), and calibration using plots, slopes, and intercepts, and the Hosmer‐Lemeshow test. Results Three RAMs were included. Each had excellent discrimination with AUROC ≥ 0.85. However, calibration was generally poor, with calibration slopes significantly different from 1 (0.71, P < .001; 1.44, P = .002; 0.68, P < .001), intercepts significantly different from 0 (−1.64, P < .001; −0.62, P < .001; 0.78, P < .001), and Hosmer‐Lemeshow test P < .001 for each. Exceptions included the Arlikar et al and Atchison et al RAMs for pediatric HA‐VTE in non‐intensive care unit (ICU) patients and ICU patients, respectively, despite derivation from ICU and non‐ICU patients, respectively. In these subpopulations, both showed excellent discrimination and good calibration. Conclusion Given the lack of adequate calibration for evaluated RAMs, further investigation and refinement of RAMs for pediatric HA‐VTE is needed prior to application of a RAM in a clinical setting or risk‐stratified clinical trial of primary thromboprophylaxis against HA‐VTE in children.

A New Risk Assessment Model for Hospital-Acquired Venous Thromboembolism in Critically Ill Children: A Report From the Children’s Hospital-Acquired Thrombosis Consortium

“…In hospitalized children, there is a paucity of both RCTs and the RAMs to inform the design of such VTE prevention measures. Progress in this area has been limited by the lower occurrence rate of HA-VTE in children than in adults and also by the scarcity of multicenter cooperative efforts to develop and validate pediatric-specific HA-VTE RAMs (6,7). Although the overall occurrence rate is low, pediatric HA-VTE has been identified as the second leading cause of preventable harm in hospitalized children (8).…”

Venous Thromboembolism among Critically Ill Children: A Narrative Review

“…For critically ill children admitted to the pediatric intensive care unit (PICU), VTE rates vary by presence of thrombophilia (both genetic and acquired), immobility, severity of illness, and clinical factors such as extended length of stay, mechanical ventilation, central venous catheters (CVC), patient age, concurrent infection, hematologic malignancy, or traumatic injury. [6][7][8][9][10][11][12][13][14][15] The development of VTE in this population carries a significant risk for adverse clinical outcomes, including index mortality and reduced ventilator-free days. 12 For adults, routine thromboprophylaxis during hospitalization is recommended by the American College of Physicians 16 and recent assessments reveal these guidelines are generally adhered to.…”

Risk Factors for the Development of Hospital-Acquired Pediatric Venous Thromboembolism: Dealing With Potentially Causal and Confounding Risk Factors Using Directed Acyclic Graph (Dag) Analysis

“…One could argue that the persistence of LOS as a risk factor would be a small sample size issue. However, even larger studies (19,20), including a recent comparative validation study of risk assessment models for pediatric hospital-acquired venous using the Children’s Hospital-Acquired Thrombosis (CHAT) registry(21), still confirm the importance of LOS. Another reason would be the fact that unknown elements, such as biological or biochemical factors involved in the genesis of VTE, are not yet understood, identified, or available in clinical studies.…”