Additional file 5: Fig. S4. ROC curve analysis for predicting poor outcome in patients with critical COVID-19 receiving ECMO. (A) ROC curve for age, (B) body mass index, (C) number of ventilator days before starting ECMO, (D) number of ECMO experiences at an institution for patients with critical COVID-19, and (E) number of ECMO days. ROC, receiver operating characteristic curve; COVID-19, coronavirus disease 2019; ECMO, extracorporeal membrane oxygenation

Additional file 5: Fig. S4. ROC curve analysis for predicting poor outcome in patients with critical COVID-19 receiving ECMO. (A) ROC curve for age, (B) body mass index, (C) number of ventilator days before starting ECMO, (D) number of ECMO experiences at an institution for patients with critical COVID-19, and (E) number of ECMO days. ROC, receiver operating characteristic curve; COVID-19, coronavirus disease 2019; ECMO, extracorporeal membrane oxygenation

Additional file 1: Supplemental Figure 1. Lifestyle factors assessed in a dose-dependent manner using the least-squares method.

Additional file 2: Fig. S1. Serial changes in the number of patients with severe COVID-19 receiving mechanical ventilation and ECMO, and the serial proportion of patients who had ECMO added to mechanical ventilation. There have been five outbreaks of COVID-19 in Japan to date, and the number of patients receiving mechanical ventilation increased continuously. However, the proportion of patients changed from mechanical ventilation to ECMO decreased continuously. The gray bars indicate the numbers of patients...

Additional file 2: Fig. S1. Serial changes in the number of patients with severe COVID-19 receiving mechanical ventilation and ECMO, and the serial proportion of patients who had ECMO added to mechanical ventilation. There have been five outbreaks of COVID-19 in Japan to date, and the number of patients receiving mechanical ventilation increased continuously. However, the proportion of patients changed from mechanical ventilation to ECMO decreased continuously. The gray bars indicate the numbers of patients...

Additional file 3: Fig. S2. Serial changes in the survival rates of patients with severe COVID-19 receiving mechanical ventilation (A) and ECMO (B). (A) The number of patients receiving mechanical ventilation increased with each outbreak from the first to the fifth outbreaks; however, the survival rate improved continuously. The gray bars indicate the numbers of survivors, the black bars indicate the numbers of deaths, and the white circles indicate the survival rates. (B) The survival...

Additional file 4: Fig. S3. ROC curve analysis for predicting poor outcome in patients with severe COVID-19 receiving mechanical ventilation. (A) ROC curve for age, (B) for body mass index, (C) for the number of ventilator days, and (D) for the number of mechanical ventilations experienced at an institution for patients with severe COVID-19. ROC, receiver operating characteristic curve; COVID-19, coronavirus disease 2019

Additional file 4: Fig. S3. ROC curve analysis for predicting poor outcome in patients with severe COVID-19 receiving mechanical ventilation. (A) ROC curve for age, (B) for body mass index, (C) for the number of ventilator days, and (D) for the number of mechanical ventilations experienced at an institution for patients with severe COVID-19. ROC, receiver operating characteristic curve; COVID-19, coronavirus disease 2019

Additional file 1: Supplemental Figure 1. Lifestyle factors assessed in a dose-dependent manner using the least-squares method.

Additional file 3: Fig. S2. Serial changes in the survival rates of patients with severe COVID-19 receiving mechanical ventilation (A) and ECMO (B). (A) The number of patients receiving mechanical ventilation increased with each outbreak from the first to the fifth outbreaks; however, the survival rate improved continuously. The gray bars indicate the numbers of survivors, the black bars indicate the numbers of deaths, and the white circles indicate the survival rates. (B) The survival...