Note: The risk of bias by domain corresponds to the highest risk of bias among outcomes by domain.
The overall risk of bias corresponds to the overall highest risk of bias assessed among outcomes.
| Bias | Author's judgement | Support for judgement |
| Randomization |
Low |
Quote: "Patients were randomized in a 2:1 ratio to receive convalescent plasma or standard of care using a secure, concealed, computer-generated, web-accessed randomization sequence (REDCap)".
Comment: Allocation sequence random. Allocation sequence concealed. Imbalances in baseline characteristics appear to be compatible with chance. |
| Deviations from intervention |
Some concerns |
Quote: "open-label trial".
Comment: Unblinded study (participants and personnel/carers). No participant cross-over. Antivirals and corticosteroids were balanced between groups. No information on administration of co-interventions of interest: biologics. Antivirals and corticosteroids were reported. Hence, no information on whether deviations arose because of the trial context. Our analysis for the outcome is an intention-to-treat analysis. This method was considered appropriate to estimate the effect of assignment to intervention. Risk assessed to be some concerns for the outcomes: Mortality (D28). Mortality (D60 or more) Time to death. WHO score 7 and above (D28). Time to WHO score 7 and above. Serious adverse events. |
| Missing outcome data |
Low |
Comment: 940 participants randomized; 921 participants analyzed. 938 analyzed for mortality (D60 and more) and time to death.
Data available for all or nearly all participants randomized Risk assessed to be low for the outcomes: Mortality (D28). Mortality (D60 or more). Time to death. WHO score 7 and above (D28). Time to WHO score 7 and above. and Serious adverse events. |
| Measurement of the outcome |
Some concerns |
Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups. Unblinded study (outcome assessor). MORTALITY, TIME TO DEATH Mortality is an observer-reported outcome not involving judgement. Risk assessed to be low for the outcome: Mortality (D28). Mortality (D60 or more). Time to death. (TIME TO) WHO SCORE 7 AND ABOVE For WHO score 7 and above, we consider that the assessment cannot possibly be influenced by knowledge of intervention assignment. Risk assessed to be low for the outcomes: WHO score 7 and above (D28). Time to WHO score 7 and above. SERIOUS ADVERSE EVENTS The authors reported on serious adverse events that may contain both clinically- and laboratory-detected events, which can be influenced by knowledge of the intervention assignment, but is not likely in the context of the pandemic. Risk assessed to be some concerns for the outcome: Serious adverse events. |
| Selection of the reported results |
Low |
Comment: The protocol, statistical analysis plan (retrospective, May 04th, 2020) and the trial registry were available (prospective, dated April 16th, 2020).
Outcome pre-specified. Results were not selected from multiple outcome measurements or analyses of the data. Trial analyzed as pre-specified. Risk assessed to be low for the outcomes: Mortality (D28). Mortality (D60 or more). Time to death. WHO score 7 and above (D28).Time to WHO score 7 and above. Serious adverse events. |
| Overall risk of bias |
Some concerns |