Introduction: High-flow oxygen therapy (HFO) and non-invasive ventilation (NIV) are non-invasive systems that are administered post-extubation in COVID-19 patients to avoid reintubation. However, the evidence on the choice of any of these devices is not very clear. The objective was to determine if the group that received OAF compared to the group that received NIV is associated with a lower risk of reintubation in adults with difficult weaning and extubated due to COVID-19. Material and methods: Retrospective cohort study in 206 records of patients in difficult weaning from mechanical ventilation in the Intensive Care Unit (ICU). The primary outcome was reintubation in patients who failed HFO or post-extubation NIV, and the secondary outcomes were ICU hospital stay and 90-day mortality. Results: Two hundred and six patients met the inclusion criteria, 102 patients in the OAF group and 1...