Fig. 3.

The 28-day mortality from randomization (day 1) to day 28. a Kaplan–Meier analysis was used to estimate the 28-day mortality, and survival curves were compared with the Wilcoxon test (P = 0.27) among patients with COVID-19. Cox regression was used for multiple comparisons (P = 0.31, HR, 0.50 [95% CI 0.2 to 1.8]). b Kaplan–Meier analysis was used to estimate the 28-day mortality and survival curves were compared with the Wilcoxon test (P = 0.06) among severe COVID-19 patients (baseline SOFA score ≥ 3). Cox regression was used as multiple comparisons (P = 0.07, HR, 0.32 [95% CI 0.10–1.06]). HDIVC high-dose intravenous vitamin C, COVID-19 coronavirus disease 2019, SOFA Sequential Organ Failure Assessment