A Multi-center, Prospective, Observational-cohort controlled study of Clinical Outcomes following COVID-19 Convalescent plasma therapy in hospitalized COVID-19 patients

Background: The SARS-CoV2 pandemic has caused high inpatient mortality and morbidity throughout the world. COVID19 convalescent plasma has been utilized as a potential therapy for patients hospitalized with COVID19 pneumonia. This study evaluated the outcomes of hospitalized COVID19 patients treated with COVID19 convalescent plasma in a prospective, observational multicenter trial. Methods: From April 2020 through August 2020, hospitalized COVID19 patients at 16 participating hospitals in Colorado were enrolled and treated with COVID19 convalescent plasma (CCP) and compared to hospitalized patients with COVID19 who were not treated with convalescent plasma. Plasma antibody levels were determined following the trial given that antibody tests were not approved at the initiation of the trial. CCP-treated and untreated COVID19 hospitalized patients were matched using propensity scores followed by analysis for length of hospitalization and inpatient mortality. Results: 542 total hospitalized COVID19 patients were enrolled at 16 hospitals across the region. A total of 468 hospitalized COVID19 patients were entered into propensity score matching with 188 patients matched for analysis in the CCP-treatment and control arms. Fine-Gray models revealed increased length of hospital stay in CCP-treated patients and no change in inpatient mortality compared to controls. In subgroup analysis of CCP-treated patients within 7 days of admission, there was no difference in length of hospitalization and inpatient mortality. Conclusions: These data show that treatment of hospitalized COVID19 patients with CCP did not significantly improve patient hospitalization length of stay or inpatient mortality.