Methods
Institutional Review Board (IRB) of Montefiore Medical Center approval was obtained for this study. In this retrospective analysis, we present data on 27 patients admitted to the hospital for symptomatic COVID-19 between March 1 and May 31, 2020. Due to the emerging data on coagulopathy, all COVID-19 patients were followed by the Pediatric Hematology consult service during this time. Primary provider teams consulted the hematology service for all confirmed COVID-19 cases, which minimized selection bias. Only patients hospitalized for symptomatic COVID-19 were included: those admitted for another reason and found to have incidental COVID-19 infection were excluded. Diagnosis of COVID-19 was confirmed in all cases by nasopharyngeal swab PCR. D-dimer was measured using the Stago Liquid Xa assay in our clinical hematology laboratory.
Hospital records were reviewed for laboratory, clinical, radiographic and demographic data. This included comorbid conditions and concurrent medications. Descriptive statistics, including proportions, means, and standard deviations, were calculated for study variables. Associations of risk factors with thrombosis were analyzed using Chi-square or Fisher Exact tests and odds ratios (ORs) also were calculated for these comparisons. Additionally, a logistic regression analysis including the variables found to be significant in bivariate analyses was run to control for confounding and determine which factors independently predicted thrombosis. For each analysis any cases with missing data were excluded.