Effect of hydrogen/oxygen therapy for ordinary COVID-19 patients: a propensity-score matched case-control study

Abstract Background Hydrogen/oxygen therapy contribute to ameliorate dyspnea and disease progression in patients with respiratory diseases. Therefore, we hypothesized that hydrogen/oxygen therapy for ordinary coronavirus disease 2019 (COVID-19) patients might reduce the length of hospitalization and increase hospital discharge rates. Methods This retrospective, propensity-score matched (PSM) case–control study included 180 patients hospitalized with COVID-19 from 3 centers. After assigned in 1:2 ratios by PSM, 33 patients received hydrogen/oxygen therapy and 55 patients received oxygen therapy included in this study. Primary endpoint was the length of hospitalization. Secondary endpoints were hospital discharge rates and oxygen saturation (SpO2). Vital signs and respiratory symptoms were also observed. Results Findings confirmed a significantly lower median length of hospitalization (HR = 1.91; 95% CIs, 1.25–2.92; p