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 |
High |
Quote: "Randomized Clinical Trial". "But during recruitment and as the trial was non-blinded, the high protective efficacy detected for ivermectin made the researchers to stop prematurely the non-intervention arm." Comment: No information on allocation sequence generation. Allocation sequence probably not concealed. Imbalances in baseline characteristics appear to be compatible with chance. |
| Deviations from intervention |
Low |
Quote: “open label-controlled study”.
Comment: Unblinded study. (participants and personnel/carers) Deviations from intended intervention arising because of the study context: No participant cross-over. No co-interventions of interest (vaccines) were available at the time of the study. Hence, deviations did not arise 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 low for the outcome: Confirmed or probable symptomatic COVID-19 |
| Missing outcome data |
Some concerns |
Comment: 340 participants randomized; 304 participants analyzed.
Data not available for all or nearly all participants randomized. No evidence the result was not biased. Reasons for missing data: loss to follow-up (25/228 [11%] vs 11/112 [10%]). Missingness could depend on the true value of the outcome. Not likely that missingness depended on the true value of the outcome (equal proportion of missingness between arms and same reason for missingness). Risk assessed to be some concerns for the outcome: Confirmed or probable symptomatic COVID-19. |
| 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). Incidence of symptomatic COVID-19 (which includes probable or suspected cases) contains clinically-detected and patient-reported outcomes which can be influenced by knowledge of intervention assignment but is not considered likely to in the context of a pandemic. Risk assessed to be some concerns for the outcomes: Confirmed or probable symptomatic COVID-19. |
| Selection of the reported results |
Low |
Comment: The protocol and trial registry were available.
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: Confirmed or probable symptomatic COVID-19. |
| Overall risk of bias |
High |