Objective: Studies in the literature regarding the use of remdesivir to treat COVID-19 patients have shown conflicting results. This study sought to answer questions related to the use of remdesivir for the treatment of patients hospitalized with moderate to severe COVID-19. Methods: This was a systematic review and meta-analysis including phase 3 randomized clinical trials (RCTs) and observational cohort studies selected from various databases, comparing patients hospitalized with moderate to severe COVID-19 receiving remdesivir and controls. Results: A total of 207 studies were retrieved, 9 of which met the eligibility criteria and were included in the study. The meta-analysis using RCTs alone showed no statistically significant differences regarding mortality or use of mechanical ventilation/extracorporeal membrane oxygenation between remdesivir and control groups, and the quality of evidence was moderate and low, respectively. The use of remdesivir increased the recovery rate by 6% (95% CI, 3-9); p = 0.004) and the clinical improvement rate by 7% (95% CI, 1-14); p = 0.02). Additionally, no significant differences in mortality were found between remdesivir and control groups when the meta-analysis used observational cohort studies alone (risk difference = -0.01 (95% CI, -0.02 to 0.01; p = 0.32), the quality of evidence being moderate, and the risk of adverse events was 4% ([95% CI, -0.08 to 0.01]; p = 0.09). Conclusions: The use of remdesivir for the treatment of patients with moderate to severe COVID-19 had no significant impact on clinically important outcomes.

Keywords: Antiviral agents; COVID-19; SARS-CoV-2.

Objective: To evaluate the efficacy of wearing a mask to prevent COVID-19 infection. Methods: This was a systematic review and meta-analysis of cohort and case-control studies, considering the best level of evidence available. Electronic databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trials.gov) were searched to identify studies that evaluated the effectiveness of wearing masks compared with that of not wearing them during the COVID-19 pandemic. Risk of bias and quality of evidence were assessed using the Cochrane risk of bias tool and the Grading of Recommendations Assessment, Development, and Evaluation. Results: Of the 1,028 studies identified, 9 met the inclusion criteria (2 cohort studies and 7 case-control studies) and were included in the analysis. The meta-analysis using cohort studies alone showed statistically significant differences, wearing a cloth mask decreased by 21% [RD = -0.21 (95% CI, -0.34 to -0.07); I2 = 0%; p = 0,002] the risk of COVID-19 infection, but the quality of evidence was low. Regarding case-control studies, wearing a surgical mask reduced the chance of COVID-19 infection [OR = 0.51 (95% CI, 0.37-0.70); I2 = 47%; p = 0.0001], as did wearing an N95 respirator mask [OR = 0.31 (95% CI, 0.20-0.49); I2 = 0%; p = 0.00001], both with low quality of evidence. Conclusions: In this systematic review with meta-analysis, we showed the effectiveness of wearing masks in the prevention of SARS-CoV-2 infection regardless of the type of mask (disposable surgical mask, common masks, including cloth masks, or N95 respirators), although the studies evaluated presented with low quality of evidence and important biases.

Keywords: Antiviral agents; COVID-19; SARS-CoV-2; Masks.