Risk of bias for analysis 2.1 All‐cause mortality – at 28 to 30 days, or in‐hospital.
| Study | Bias | |||||||||||
| Randomisation process | Deviations from intended interventions | Missing outcome data | Measurement of the outcome | Selection of the reported results | Overall | |||||||
| Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | |
| Subgroup 2.1.1 Ambulatory, mild | ||||||||||||
| AlQahatani 2022 | Low risk of bias | The allocation sequence was random. No information regarding allocation concealement but there is not much differences in the baseline characters, except for the number of diabetes patients:‐ 22% patients in Favipiravir group and 38% in control group. | Low risk of bias | There was no deviations from the intended intervention and appropriate analysis was done.only 1 patient in the favipiravir group stopped taking medicine due to headache. (1/54) | Low risk of bias | No outcomes were missing for mortality. | Low risk of bias | No bias in measurement. | Low risk of bias | Clinical trials registration. NCT04387760. Registration date: 07/05/2020. Mortality rate was mentioned and is reported, | Low risk of bias | All the domains are low risk of bias. |
| Golan 2022 | Low risk of bias | "Randomization was performed via an Interactive Web Randomization System and maintained by a third party." Comment: Allocation sequence random. Allocation sequence probably concealed. Imbalances in baseline differences not significant. | Low risk of bias | "double‐blind" study. Comment: Blinded study (participants and personnel/carers). | Low risk of bias | data available for all randomised | Low risk of bias | Method of measuring the outcome probably appropriate. | Low risk of bias | The prospective registry was available (dated October 23, 2020) Outcome pre‐specified.Results were not selected from multiple outcome measurements or analyses of the data. Trial analyzed as pre‐specified. | Low risk of bias | low |
| Shah 2023 | Low risk of bias | Eligible patients were randomly assigned using a permuted block design, in a 1:1 ratio, to receive open‐label oral favipiravir plus standard care or standard care alone. Randomisation was conducted by an appropriately delegated member of the study team, using a centralised online portal. Baseline character distribution was similar. |
Low risk of bias | OPEN label trial. All analyses were performed using STATA 13·1 and according to the principle of intention to treat. Data are presented as hazard ratios (HRs) with 95% CIs. All statistical tests were two‐sided and a p value of less than 0·05 was considered significant. No data was imputed and missing data was assumed to occur at random. The PIONEER study was registered with ClinicalTrials. gov, NCT04373733. | Low risk of bias | 499 randomised and all outcomes are available. | Low risk of bias | No bias in measuring mortality. | Low risk of bias | protocol and analysis plan available | Low risk of bias | All domains are low risk of bias. |
| Subgroup 2.1.2 Moderate, severe or critical | ||||||||||||
| Mahmudie 2022 | Some concerns | Double‐blind study. Randomly allocated into two groups. Permuted balanced blocked randomization using a sealed envelope website. Allocation concealment is also guaranteed by the same. some differences in baseline characteristics were reported between groups. Age not matched.Favipiravir:‐ 34.86 (15.95) vs placebo:‐71.91 (15.87) Hb low, WBC high, Lymphocytes high, platelets high, ESR high, PCO2 high, PCO3 high in Favipiravir group |
High risk of bias | Double blind allocation concealed no information regarding if appropriate analysis were used to estimate the effect of assignment to intervention |
Low risk of bias | data for this outcome is available for all participants randomized(n=97) | High risk of bias | method of measuring the outcome‐no information. Outcome assessors were not aware of the intervention‐double blind study |
High risk of bias | no information if data were produced as a result of a pre‐specified analysis plan and multiple eligible outcome measurements were used within the outcome domain. | High risk of bias | high risk |
| Solaymani‐Dodaran 2021 | Low risk of bias | “Sealed envelopes were used to protect the randomization sequence. We used a central allocation mechanism in which participating centers called a central randomization unit, and registered their eligible patients to receive the 4‐digit unique code for assigned group identification” allocation sequence random and concealed.Baseline differences balanced between groups | Low risk of bias | Open Label trial. No details about whether patients aware of their allocated treatment.No obvious deviation from intervention and Performed Modified ITT for analysis which can be considered appropriate | Low risk of bias | data for this outcome available for all participants randomized | Low risk of bias | low risk | Some concerns | no information on pre‐specified analysis plan | Some concerns | some concerns |
| Tabarsi 2021 | Low risk of bias | “The allocation was according to the block randomization method. 16 blocks, including 4 patients in each block, were generated by the Online Randomizer website (www.sealesenvelop.com/simple randomizer).” Allocation sequence random and probably concealed | Some concerns | no information if participants, carers aware of assigned intervention during the trial | Low risk of bias | data for this outcome available for all, or nearly all, participants randomized. 175Favipiravir and 178placebo |
Some concerns | per protocol analysis used | Some concerns | no information if outcomes were analysed in accordance with a pre‐specified analysis plan. protocol available but the analysis plan is unavailable. | High risk of bias | high risk |