Zeng 2020.

Study characteristics
Methods	Trial design: retrospective matched controlled study Type of publication: journal online, ahead of print Setting: ICU Recruitment dates: NR Country: China Language: English Number of centres: 2 Trial registration number: NR Date of trial registration: NR
Participants	Age: median 61.5 years in CP group, median 73 years in control group Gender: 5 male, 1 female in CP group; 11 males, 4 females in control group Ethnicity: NR Number of participants (recruited/allocated/evaluated): 21 (6 received CP, 15 in control group) Severity of disease: critical (admitted to ICU) Co‐morbidities: pregnancy, diabetes, hypertension, cardiovascular disease (CP group) Inclusion criteria: critically ill patients  Exclusion criteria: NR Previous treatments (e.g. experimental drug therapies, oxygen therapy, ventilation): antibiotics (100%), antiviral therapy (67%), traditional Chinese medicine (50%),  IVIG (83%), steroid therapy (67%), high‐flow oxygen therapy (100%), mechanical ventilation (83%), renal replacement therapy (33%), ECMO (67%) in the CP group
Interventions	Intervention(s): CP therapy Details of CP: Type of plasma: NR Volume: median 300 mL (range 200‐600mL)  Number of doses: 1‐2 Type of antibody test(s) and antibody‐titre(s): Gold immunochromatography for SARS‐CoV‐2 IgM and IgG tests were performed using blood sample (New Coronavirus [2019‐nCoV] Antibody Detection Kit, Shanghai Outdo Biotech and Tangshan Innovita Biotech). Pathogen inactivated: NR RT‐PCR tested: NR Details of donors:  Gender: NR HLA and HNA antibody‐negative: NR Severity of disease: NR Timing from recovery from disease: NR RT‐PCR tested: NR Treatment details, including time of plasma therapy (e.g. early stage of disease): critically ill patients  Comparator: Not applicable Concomitant therapy: antibiotics (100%), antiviral therapy (67%), traditional Chinese medicine (50%),  IVIG (83%), steroid therapy (67%), high‐flow oxygen therapy (100%), mechanical ventilation (83%), renal replacement therapy (33%), ECMO (67%) in the CP group. Unclear whether these treatments were stopped before plasma transfusion or continuously given Duration of follow‐up: NR Treatment cross‐overs: Not applicable Compliance with assigned treatment: good (all compliant)
Outcomes	Primary study outcome(s):  survival  Primary review outcomes All‐cause mortality at hospital discharge: reported (5 of 6 patients died) Time to death: reported  Secondary review outcomes Number of participants with grade 3 and grade 4 AEs, including potential relationship between intervention and adverse reaction (e.g. TRALI, transfusion‐transmitted infection, TACO, TAD, acute transfusion reactions): none Number of participants with SAEs: none Improvement of clinical symptoms, assessed through need for respiratory support at up to 7 days; 8‐15 days; 16‐30 days: NR 30‐day and 90‐day mortality: reported Admission on the ICU: reported (all admitted) Length of stay on the ICU: NR Time to discharge from hospital: reported (1 discharged) QoL: NR Additional study outcomes: duration of viral shedding
Notes	Sponsor/funding: supported by The National Natural Science Foundation of China (No. 81970517), Zhongyuan (Henan) Thousands Outstanding Talents Plan (No. ZYQR201912179), Foundation for Distinguished Young Talents of Zhengzhou University Medical School (No.2020ZQLMS), and The Key Scientific Research Project of Henan Higher Education Institutions of China (No. 20B320028). COIs: the authors have no potential conflicts of interest to disclose. Other: written informed consents were obtained from all the family members of patients who received plasma.