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: “Computer generated randomization. Sequentially numbered, sealed, opaque envelopes.” [Registry] “Eligible subjects were randomized with a computer-generated random number table (www.randomizer.org) in to ei- ther group A (HFNC) or group B (NIV) according to a computer-generated random number table. Allocation concealment was done with sealed-envelope technique.” [Report]
Comment: Allocation sequence random. Allocation sequence concealed. |
| Deviations from intervention |
Some concerns |
Quote: “The subject and the clinical management team were not blinded to the allocated intervention.”
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: biologics, antivirals and corticosteroids. Hence, no information on whether deviations arose because of the trial context. Our analysis for the binary outcome is an 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). Time to death. Time to WHO score 7 and above. |
| Missing outcome data |
Low |
Comment: 109 participants randomized; 109 participants analyzed.
Data available for all or nearly all participants randomized. Risk assessed to be low for the outcomes: Mortality (D28). Time to death. Time to WHO score 7 and above. |
| Measurement of the outcome |
Low |
Quote: “An independent investigator unaware of the group allocation noted the outcome variables after 48 h of randomization and thereafter from the subjects’ database and files.”"outcome assessors were blinded, and predefined intubation criteria were followed."
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). Time to death. Time to WHO score 7 and above. |
| Selection of the reported results |
Some concerns |
Comment: The prospective registry was available.
Outcomes were not pre-specified (different time points from the registry). No information on whether the result was selected from multiple outcome measurements or analyses of the data. Trial probably not analyzed as pre-specified. Risk assessed to be some concerns for the outcome: Mortality (D28). Time to death. Time to WHO score 7 and above. |
| Overall risk of bias |
Some concerns |