COVID-19(6) pandemic(4) children(2) immunology(2) Cohort(2) Patient(2) disease(2) parent(2) enrolled(2) Anxiety(2) significantly higher(2) hospitals(2) management(2) Follow-up(2) Volume(2) effective(2) correlated(2) COVID-19, Coronavirus disease 2019(2) surgery(2) Migration(2) death(2) Care(2) no statistical difference(2) proportion(2) pediatric(2) coronavirus disease(2) ARDS, acute respiratory distress syndrome(2) China(2) Impact(2) group(2)