Fig. 3From: Outcomes of patients aged ≥80 years with respiratory failure initially treated with non-invasive ventilation in European intensive care units before and during COVID-19 pandemicKaplan–Meier curves comparing a crude 30-day mortality between patients treated initially with NIV who required and who did not require intubation, stratified by study. This curves represent pint estimates with 95% confidence intervalsBack to article page