Figure 1

Kaplan-Meier Estimated Probability of Remaining in the ED. Legend:___ = invasive ventilation only ---- = non-invasive ventilation only, ---- = both invasive and non-invasive ventilation.
Kaplan-Meier Estimated Probability of Remaining in the ED. Legend:___ = invasive ventilation only ---- = non-invasive ventilation only, ---- = both invasive and non-invasive ventilation.