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. No participant cross-over. No information on administration of co-interventions of interest: antivirals, corticosteroids, biologics. Appropriate method of analysis used; participants analyzed according to randomization assignment. |
| Missing outcome data |
Low |
Comment: 191 patients randomized; 191 patients analyzed.
Data available for all participants. Risk assessed to be low for the outcome: Mortality. |
| Measurement of the outcome |
Low |
Comment: No information on blinding of outcome assessor.
Mortality is an observer-reported outcome not involving judgement. Risk assessed to be low for the outcome: Mortality. |
| Selection of the reported results |
Some concerns |
Comment: Neither the protocol nor the statistical analysis plan was available. The trial registration was available.
Mortality was specified at 2 weeks in the registry vs 28 days in the published article. No information on whether the result was selected from multiple outcome measurements or analyses of the data. Trial not analyzed as pre-specifed. Risk assessed to be some concerns for the outcome: Mortality. |
| Overall risk of bias |
Some concerns |