Trial IRCT20111224008507N3
Publication Shahbaznejad L, Clin Ther (2021) (published paper)
Primary outcome on the report: Clinical improvement after baseline defined as resolving patients’ baseline status on persistent and continuous cough (coughing a lot for more than an hour, or ≥3 coughing episodes in 24 hours that interferes with daily life and ability to work) and tachypnea in addition to increasing oxygen saturation >94%.

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: "The patients were randomly divided into two intervention and control groups by simple randomization method with a table of random numbers" "Neither the participants nor the evaluators were aware of the randomization process or group allocation."
Comment: Allocation sequence random. Unclear allocation concealment.
Deviations from intervention
Low 		Quote: "Double blind. Neither the participants nor the evaluators were aware of the randomization process or group allocation." "Groups that have been masked: participant and care provider (registry)."
Comment: Blinded study (participants and personnel/carers).
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 outcomes: Mortality (D28).
Missing outcome data
Some concerns 		Comment: 73 participants randomized; 69 participants analyzed.
Data not available for nearly all participants randomized.
No evidence that the result is not biased.
Reasons: four withdrawals from the study, all participants were allocated to the control group receiving standard of care (no further details provided).
Missingness could depend on the true value of the outcome.
Not likely that missingness depended on the true value of the outcome.
Risk assessed to be some concerns for the outcomes: 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.
Blinded study (outcome assessor).
Risk assessed to be low for the outcomes: Mortality (D28).
Selection of the reported results
Low 		Comment: The protocol and statistical analysis plan were not available, the registry was retrospective (dated June 27th, 2020).
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.
Mortality outcome was not pre-specified in the registry; however, we do not consider the reporting of this outcome to be selective since mortality should be reported even if not planned.
Risk assessed to be low for the outcome: Mortality (D28).
Overall risk of bias
Some concerns