| Bias | Author's judgement | Support for judgement |
| Randomization |
Low |
Quote: "patients were randomly assigned in a 2:1 ratio to receive either UC-MSCs or the placebo, in addition to standard care, using an interactive web response management system (IWRS). A permutated-block randomisation sequence that was stratified by the trial sites was generated and uploaded to the system."
Quote: "A barcode-based product management system (Product Identification Authentication and Tracking System, PIATS) was introduced in this study to manage and track the study products logistics, e.g., preparation, packaging, shipping, storage, and clinical administration to the patients. The application of PIATS could realize the blind label processing by non-informative unique barcodes of the clinical study drug. The concealment of the randomisation sequence could be ensured using PIATS and IWRS." Comment: Allocation sequence random. Allocation sequence concealed. |
| Deviations from intervention |
Low |
Quote: "Patients, investigators, and outcome assessors (independent central imaging reviewers) were all blinded to the treatment allocation. Blinding was also ensured by the product marking, with the UC-MSCs and the placebo having a similar appearance and packaging."
Comment: Blinded study (patients, physicians, investigators, and outcome assessors). Data were analyzed using intention-to-treat analysis. |
| Missing outcome data |
Low |
Comment: 101 patients randomized; 100 patients analyzed.
One participant in the intervention group withdrew consent before treatments were administered and was not included in analyses. Risk assessed to be low for the outcomes: Mortality. WHO score 6 and above. WHO score 7 and above. Adverse events. Serious adverse events. |
| Measurement of the outcome |
Low |
Comment: Blinded study (outcome assessor).
Risk assessed to be low for the outcomes: Mortality. WHO score 6 and above. WHO score 7 and above. Adverse events. Serious adverse events. |
| Selection of the reported results |
Low |
Comment: The protocol and statistical analysis plan were available. Data analyzed and presented as pre-specified.
Risk assessed to be low for the outcomes: Mortality. WHO score 6 and above. WHO score 7 and above. Adverse events. Serious adverse events. |
| Overall risk of bias |
Low |