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: "An electronically generated randomization 2:1 list was prepared by independent statisticians" "The list was accessible only to nonmasked specialists in the study in an attempt to minimize observation bias" Comment: It was not clear whether the allocation was concealed or not. Baseline characteristics between intervention groups were comparable (except for high blood pressure and diabetes mellitus, known risk factors for unfavorable disease progression, which were more frequent in patients not treated with calcifediol); any differences appear to be compatible with chance. |
| Deviations from intervention |
Some concerns |
Quote: "This pilot study has several limitations as it is not double-blind placebo controlled"
Comment: Unblinded study (participants and personnel/carers) Deviations from intended intervention arising because of the study context: No participant cross-over. No information on key co-interventions such as antivirals and corticosteroids reported 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). Clinical improvement (D28). |
| Missing outcome data |
Low |
Comment: 76 participants randomized, 76 participants analyzed for all outcomes (pilot study).
Data available for all participants randomized. Risk assessed to be low for outcome: Mortality (D28). Clinical improvement (D28). |
| 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) MORTALITY Mortality is an observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Mortality (D28). CLINICAL IMPROVEMENT [choose relevant outcomes] Clinical improvement (defined as discharge) requires clinical judgement and could be affected by knowledge of intervention receipt, but it not considered likely to in the context of a pandemic. Risk assessed to be some concerns for the outcomes: Clinical improvement (D28). |
| Selection of the reported results |
Low |
Comment: Neither the protocol nor the statistical analysis plan was available. The registry was available and utilized (version dated April 28th, 2020).
Outcome pre-specified. 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: Mortality (D28). Clinical improvement (D28). |
| Overall risk of bias |
Some concerns |