Outcome definition
Our primary outcome was escalated care, defined as hospitalization plus any of the following: HFNC, non-invasive ventilation (e.g., continuous or biphasic positive airway pressure), intubation and ventilation, or management in the ICU without airway support. The criteria for ICU admission were impair hypoxemia or hypercapnia, respiratory distress, inspired fraction of oxygen of over fifty percent, hemodynamic instability, or apnea.