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 randomly assigned (1:1) via a web-based system, according to a randomization list stratified on center”
Comment: Allocation sequence random. Allocation sequence probably concealed. |
| Deviations from intervention |
Low |
Quote: “open-label”
Comment: Unblinded study (participants and personnel/carers) Deviations from intended intervention: 1 patient in the convalescent plasma group did not receive any infusion. Administration of co-interventions of interest: antivirals (0 vs 1), corticosteroids (30 vs 23), biologics (0 vs 0) were reported. Hence, deviations did not arise 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 low for the outcomes: Mortality (D28). Mortality (D60 or more). Time to death. Clinical improvement (D28). Time to clinical improvement. WHO score 7 and above (D28). WHO score 7 and above (D60 or more). Time to WHO score 7 and above. Adverse events. Serious adverse events. |
| Missing outcome data |
Some concerns |
Comment: 120 participants randomized; 120 participants analyzed for mortality (D28), time to death, clinical improvement (D28), time to clinical improvement, WHO score 7 and above (D28). Not all participants analyzed for mortality (D60), WHO score 7 and above (D60), adverse events and serious adverse events, .
MORALITY (D28), TIME TO DEATH, CLINICAL IMPROVEMENT (D28), TIME TO CLINICAL IMPROVEMENT, WHO SCORE 7 AND ABOVE (D28), TIME TO WHO SCORE 7 AND ABOVE. Data available for all or nearly all participants randomized. Risk assessed to be low for the outcomes: Mortality (D28). Time to death. Clinical improvement (D28). Time to clinical improvement. WHO Score 7 and above (D28). Time to WHO score 7 and above. MORTALITY (D60 AND ABOVE). WHO SCORE 7 AND ABOVE (D60 AND ABOVE), SERIOUS ADVERSE EVENTS, ADVERSE EVENTS. Data not available for all or nearly all participants randomized. No evidence that the result is not biased. Reasons: censored observations. The number of missing participants is unknown. Missingness could depend on the true value of the outcome. Not likely that missingness depended on the true value of the outcome. Risk assessed to be some concerns for the outcomes: Mortality (D60 or more). WHO score 7 and above (D60 or more). Adverse events. 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 Observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Mortality (D28). Mortality (D60 or more). Time to death. (TIME TO) WHO SCORE 7 AND ABOVE For this outcome, 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). WHO score 7 and above (D60 or more). Time to WHO score 7 and above. (TIME TO) CLINICAL IMPROVEMENT Clinical improvement (defined as hospital discharge) requires clinical judgement and could be affected by knowledge of intervention receipt, but it is not considered likely to in the context of a pandemic. Risk assessed to be some concerns for the outcomes: Clinical improvement (D28). Time to clinical improvement. ADVERSE and SERIOUS ADVERSE EVENTS The authors reported on adverse events and 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 outcomes: Adverse events. Serious adverse events |
| Selection of the reported results |
Low |
Comment: The registry was consulted up to version dated April 14, 2020.
MORTALITY (D28). 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: Mortality (D28). MORTALITY (D60 OR MORE). TIME TO DEATH. CLINICAL IMPROVEMENT. TIME TO CLINICAL IMPROVEMENT. WHO SCORE 7 AND ABOVE. TIME TO SCORE 7 AND ABOVE. ADVERSE EVENTS. SERIOUS ADVERSE EVENTS. Outcome data acquired from direct contact with authors. Analysis performed by the COVID-NMA. Risk assessed to be low for the outcome: Mortality (D60 or more). Time to death. Clinical improvement (D28). Time to clinical improvement. WHO score 7 and above (D28). WHO score 7 and above (D60 or more). Time to WHO score 7 and above. Adverse events. Serious adverse events. |
| Overall risk of bias |
Some concerns |