| Bias | Author's judgement | Support for judgement |
| Confounding |
Moderate |
Comment: The following review confounders (Age, Gender, Ethnicity, Comorbidities - all besides Hypertension, Severity - via vital signs at baseline) were controlled for in the propensity score and Cox regression model. |
| Selection of participants into the study |
Serious |
Comment: Baseline was considered as the date of hospitalization. Follow-up began from this point in time. And exposure to the intervention occurred at any time during hospitalization. Start of follow up and start of treatment is not at the same moment for some patients There is a risk of immortal bias |
| Intervention classification |
Low |
Quote : « Patients were exposed to hydroxychloroquine if they had a dispensed drug from the VA bar code medication administration (BCMA) data file during their hospitalization. Similarly, if patients received azithromycin with hydroxychloroquine during their hospitalization they were categorized HC- and AZ-treated. »Comment: Study baseline was defined as date of a hospitalization Quote : « Data were extracted from the Veterans Affairs Informatics and Computing Infrastructure (VINCI), which includes inpatient, outpatient data (coded with International Classification of diseases (ICD) revision 9-CM, revision 10-CM), laboratory, and pharmacy claims. The completeness, utility, accuracy, validity, and access methods are described on the VA website, http://www.virec.research.va.gov. » |
| Deviation from intended intervention |
NI |
Quote : « All patients received standard supportive management » Comment: The information reported is inadequate to assess whether there are deviations from the intended intervention beyond what would be expected in usual practice |
| Missing data |
Low |
Comment: 807 included/807 analyzed. Risk assessed to be low for the outcomes: Mortality. Time to death. Time to WHO score 6 and above. Time to WHO score 7 and above. Incidence of Clinical improvement. |
| Measurements of outcomes |
Low |
Comment: Mortality is an observer-reported outcome not involving judgement. Incidence of WHO score 7 and above is an outcome that reflects decisions made by the intervention provider. However, we consider that the assessment of these outcomes cannot possibly be influenced by knowledge of the intervention assignment. Risk assessed to be low for outcomes: Mortality. Time to death. Time to WHO score 7 and above. For Incidence of clinical improvement (discharge), and Incidence of WHO score 6 and above, we considered that although the assessment could possibly be influenced by knowledge of the intervention assignment, it was not likely to have happened in the context of a pandemic. Risk assessed to be some concerns for outcomes: Incidence of clinical improvement. Time to WHO score 6 and above |
| Selection of the reported results |
Moderate |
Comment: The outcomes and analyses are clearly defined in the Methods section. There is no a-priori registered protocol or statistical analysis plan available. Risk assessed to be Moderate for the outcomes: Mortality. Time to death. Time to WHO score 6 and above. Time to WHO score 7 and above. Incidence of Clinical improvement. |