We included 22 trials involving 8436 adult participants, in which 4449 received Tocilizumab. Three studies were reported from US, 2 studies from Spain, and 5 studies were conducted in multiple nations. Rest of the 12 studies reported, each from Belgium, Brazil, China, Finland, France, India, Iran, Israel, Italy, Netherlands, Sweden and UK. Of the included trials only 4 trials included mild-moderate patients. Rest of the studies included severe to critically ill participants. Co-interventions varied among different trials, but >80 % of the trial participants received glucocorticoids and only <5% of the participants received Remdesivir as a co-intervention. The risk of Bias assessment was done among the trials and 11 studies were found to be of low risk of bias, out of 22, twelve studies (1,9–15) were found to have low risk of bias, 8 studies (9,16–22) have some concerns and 2 studies (1,23) were of High RoB.
All-Cause Mortality: High certainty of evidence from 21 trials (1,9–26) including 8309 participants found that Tocilizumab reduces mortality in severe to critically ill COVID-19 patients [RR 0.88, 95% CI 0.81, 0.94].
Progression to Invasive Ventilation/ECMO/Death: Moderate certainty of evidence from 18 RCTs (1,9–15,17–19,21,25) including 7127 participants found that Tocilizumab probably results in a reduction in the progression to Ventilation/ECMO/Death [RR 0.85, 95% CI 0.78,0.92].
Clinical improvement: Moderate certainty of evidence from 17 RCTs (1,9–15,18,20,21,23,25) including 6971 participants, showed that Tocilizumab probably results in a slight increase in clinical improvement in severe to critically ill Covid 19 patients [RR 1.04, 95% CI 1.00, 1.09]
Time to Clinical improvement: Low certainty of evidence from 8 RCTs (9,10,13–15,17,18,20) showed, that treating with Tocilizumab may result in slight reduction for the time to clinical improvement [HR 1.18, 95% CI 1.08,1.29]
Adverse events: The evidences from 9 RCTs (10,13,15,16,18,20–22,25) with 2363 participants are very uncertain about the effects of Tocilizumab in serious adverse effects [RR 1.11 95% CI 0.95, 1.29].
Serious Adverse Events: The evidences from 19 RCTs (1,9–13,15–18,20–23,25) with 3850 participants is very uncertain about the effects of Tocilizumab in Serious Adverse events [RR 0.94, 95% CI 0.82, 1.07].