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: “Masked randomisation was centralised and done
electronically
through an automated interactive
web-response system (IWRS). Participants were randomly assigned (1:1) to either colchicine treatment or
placebo, using an allocation sequence that was computergenerated using a blocking schema with block sizes of six. Allocation sequence was not stratified. Eligible patients were randomly assigned by research nurses through the IWRS system that provided the bottle
number to send to patients. The randomisation list was
computer-generated by an unmasked biostatistician and
uploaded to an interactive web response system
(Dacima)”
Comment: Allocation sequence random. Allocation sequence concealed. |
| Deviations from intervention |
Low |
Quote: “Randomized, double-blind trial”
Comment: Blinded study (participants, personnel/carers). Participants were analyzed according to their randomized groups for the outcome. Of note 18 participants (unclear distribution/proportion between arms) were excluded from the analysis post-randomization due to study medication not delivered at patient home (11) and eligibility issues/condition declined before delivery of study medication (7). Nevertheless, we consider this method appropriate to estimate the effect of assignment to intervention. Risk assessed to be low for the outcomes: Hospitalization or Death (D28). Mortality (D28). Adverse events. Serious adverse events. |
| Missing outcome data |
Low |
Quote: "At the time of database lock and unblinding on January 20, 2021, vital and primary endpoint event status were available for all except for 93 patients (97.9%)."
Comment: 4506 patients randomized; 4488 patients analyzed for efficacy; 4412 analyzed for adverse events and serious adverse events. Data available for all or nearly all participants. Risk assessed to be low for the outcomes: Hospitalization or death (D28). Mortality (D28). Adverse events. Serious adverse events. |
| Measurement of the outcome |
Low |
Quote: "double-blind, placebo-controlled"
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: Hospitalization or death (D28). Mortality (D28). Adverse events. Serious adverse events. |
| Selection of the reported results |
Some concerns |
Comment: The prospective trial (dated March 26th, 2020, considered as prospective due to delay of solely 3 days).
Mortality and Hospitalization or death outcome pre-specified in the registry. 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 outcomes: Hospitalization or Death (D28). Mortality (D28). Adverse events and serious adverse events were not pre-specified in the registry. No information on whether the results were selected from multiple outcome measurements or analyses of the data. Risk assessed to be some concerns for the outcome: Adverse events. Serious adverse events. |
| Overall risk of bias |
Some concerns |