Methods:

The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) Checklist was followed to improve reporting this meta-analysis

Protocol registration:

The protocol was registered in the International Prospective Reregister of Systematic Review with registration number CRD42020204233 in August 2020.
  1. Criteria for considering studies for this review

    Types of the studies:

Cohort studies either prospective or retrospective comparing the use of tocilizumab with placebo in presence of standard of care that was given to all patients according to need. Case-control studies were excluded.

Types of participant:

Patients with severe COVID-19 patients defined as those with at least reduced oxygen saturation (< 94%) or required ICU admission and patients with PCR-confirmed COVID-19. Evidence of hyperinflammatory status is not necessary but will be highlighted.

Types of interventions:

Tocilizumab intravenous (IV) with dose 400 to 800 mg once and could be repeated for another dose.

Types of outcome measures

Efficacy and adverse effects that were reported up to 28 days follow-up period