Variables
Investigators and pediatric specialists from each institution reviewed electronic health records to compile data. Variables were chosen to describe demographic characteristics, comorbidities, signs and symptoms upon admission, laboratory and imaging, and disease core variables (severe clinical manifestation, treatment, and outcomes). These variables were recorded in REDcap (electronic data capture system) and variables regarding clinical presentation, treatment and outcomes and radiological findings were recategorized for the analysis (Figure 1).
[INSERT FIGURE 1 ABOUT HERE]