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: "Randomization of the study was done at the KFMC Pharmacy, which also provided the Investigational Drug Service (IDS) clearance and the site for dispensing the supplements. The randomization scheme was computer-generated using four permuted blocks of equal size for the two treatment groups."
Comment: Allocation sequence random. Allocation sequence concealed. |
| Deviations from intervention |
Some concerns |
Quote: "The supplements provided were different in color in both packaging and tablet with unit labels stamped in both the tablet and blister, making blinding of the trial impossible."
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: antivirals, biologics, and corticosteroids. 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 outcomes: Mortality (D28). Adverse events. |
| Missing outcome data |
Some concerns |
Comment: 73 participants randomized; 69 participants analyzed of which 23 were missing with last observation carried forward.
Data not available for all or nearly all participants randomized. No evidence that the result is not biased. Reasons: Participant discontinuation due to incomplete blood sample (1 [3%] vs 2 [6%]), Died (1 [3%] vs 0), No blood sample for 2nd visit (LOCF) (12 [32%] vs. 11 [31%]).Unclear discontinuation due to incomplete blood samples affect outcomes of interest. Missingness could depend on the true value of the outcome. Not likely that missingness depended on the true value of the outcome because reasons for missing data were similar and balanced between arms. Risk assessed to be some concerns for the outcomes: Mortality (D28). 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 (interviewers were blinded but patients that reported on outcomes were not blinded). MORTALITY Mortality is an observer-reported outcome not involving judgement. Risk assessed to be low for the outcome: Mortality (D28). ADVERSE ADVERSE EVENTS The authors reported on 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. |
| Selection of the reported results |
Some concerns |
Comment: The protocol, statistical analysis plan and registry were not available.
No information on whether the result was selected from multiple outcome measurements or analyses of the data. No information on whether the trial was analyzed as pre-specified. Risk assessed to be some concerns for the outcomes: Mortality (D28). Adverse events. |
| Overall risk of bias |
Some concerns |