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: “The randomization scheme used computer generated lists performed by the clinical research center, stratified by center, with blocks of various sizes and performed through a centralized internet service to ensure allocation concealment.”
Comment: Allocation sequence random. Allocation sequence concealed. |
| Deviations from intervention |
Some concerns |
Quote: “This was an open-label study in which both participants and investigators knew to which groups participants had been randomly assigned.”
Comment: Unblinded study (participants and personnel/carers). Deviations from intended intervention arising because of the study context: No participant cross-over. No information on administration of co-interventions of interest: biologics, antivirals and corticosteroids. Hence, no information on whether deviations arose because of the trial context. Of note, 1 patient randomized to SOC received low-volume plasma; 3 patients randomized to high volume plasma received low-volume plasma. Our analysis for the binary 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 outcome: Clinical improvement (D28). |
| Missing outcome data |
Low |
Comment: 129 participants randomized; 126 participants who completed follow up in ITT analysis (129).
Data available for all or nearly all participants randomized. Risk assessed to be low for the outcome: Clinical improvement (D28). |
| 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) CLINICAL IMPROVEMENT Clinical improvement (defined as 2-point improvement on WHO clinical scale or discharge) requires clinical judgement and could be affected by knowledge of intervention receipt, but it not considered likely to in the context of a pandemic. Risk assessed to be some concerns for the outcome: Clinical improvement (D28). |
| Selection of the reported results |
Low |
Comment: The protocol, statistical analysis plan and prospective registry were available.
br/>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 outcome: Clinical improvement (D28). |
| Overall risk of bias |
Some concerns |