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 |
Some concerns |
Quote: “patients with a confirmed diagnosis of COVID-19 infection were randomized into two groups’
Comment: No information on allocation sequence. No information on allocation concealment. |
| Deviations from intervention |
Some concerns |
Comment: The trial registry describes the study as double-blinded (Participant, Care Provider), but no information is provided on what measures were taken to establish and maintain blinding such as a placebo for zinc in the control group. Comment: Unclear blinding (participants and personnel/carers) No participant cross-over. No information on administration of co-interventions of interest: antivirals, corticosteroids, biologics. Hence, no information on whether deviations arose because of the trial context. Data for the outcome were analyzed using 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: Mortality (D28). |
| Missing outcome data |
Low |
Comment: 191 participants randomized; 191 participants analyzed.
Data available for all participants randomized. Risk assessed to be low for the outcome: Mortality (D28). |
| Measurement of the outcome |
Low |
Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups. Unblinded study (outcome assessor). Mortality is an observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Mortality (D28). |
| Selection of the reported results |
Some concerns |
Comment: Neither the protocol nor the statistical analysis plan was available. The trial registration was available (dated June 23rd, 2020).
Outcome not pre-specified No information on whether the result was selected from multiple outcome measurements or analyses of the data. Trial probably not analyzed as pre-specified. Risk assessed to be some concerns for the outcome: Mortality (D28). |
| Overall risk of bias |
Some concerns |