Development of a pediatric-specific clinical probability tool for diagnosis of venous thromboembolism: a feasibility study

BACKGROUND: Pediatric venous thromboembolism (VIE) is an increasingly common, difficult to diagnose problem. Clinical probability tools (CPT) for adults estimate VIE likelihood, but are not available for children. We hypothesized that a pediatric-specific CPT is feasible. METHODS: Radiology reports were utilized to identify children imaged for suspected VIE. Relevant signs, symptoms, and comorbidity variables, identified from published literature, were extracted from corresponding medical records. Variables associated with pediatric VIE were incorporated into a multivariate logistic regression to create a pilot CPT which was confirmed on a separate cohort. RESULTS: A total of 389 subjects meeting inclusion criteria were identified: 91 with VIE and 298 without. Univariate analysis revealed male gender (odds ratio (OR) = 2.96; P < 0.001), asymmetric extremity (OR = 1.76; P = 0.033), central venous catheter utilization and/or dysfunction (OR = 2.51; P < 0.001), and cancer (OR = 2.35; P= 0.014) as VTE predictive variables. Documentation of an alternate diagnosis was inversely related to VIE (OR = 0.42; P= 0.004). Receiver operating characteristic analysis of the derived CPT demonstrated reasonable ability to discriminate VIE probability in the training cohort (area under the curve (AUC) = 0.73; P < 0.001) and moderate discrimination in a separate validation cohort of 149 children (AUC = 0.64; P= 0.011). CONCLUSION: A pediatric-specific VIE CPT is feasible, would facilitate early diagnosis, and could lead to improved outcomes.