Decreased Mortality in Coronavirus Disease 2019 Patients Treated With Tocilizumab: A Rapid Systematic Review and Meta-analysis of Observational Studies

Background: We systematically reviewed the literature to answer the following research questions: (1) Does interleukin 6 (IL-6) (receptor) antagonist therapy reduce mortality in coronavirus disease 2019 (COVID-19) patients compared to patients not treated with IL-6 (receptor) antagonists; and (2) is there an increased risk of side effects in COVID-19 patients treated with IL-6 (receptor) antagonists compared to patients not treated with IL-6 (receptor) antagonists? Methods: We systematically searched PubMed, PMC PubMed Central, Medline, World Health Organization COVID-19 Database, Embase, Web of Science, Cochrane Library, Emcare, and Academic Search Premier (through 30 June 2020). Random effects meta-analysis was used to pool the risk ratios and risk differences of individual studies. Risk of bias was appraised using the Methodological Index for Non-randomized Studies (MINORS) checklist. Results: The search strategy retrieved 743 unique titles, of which 10 studies (all on tocilizumab [TCZ]) comprising 1358 patients were included. Nine of 10 studies were considered to be of high quality. Meta-analysis showed that the TCZ group had lower mortality than the control group. The risk ratio was 0.27 (95% confidence interval [CI], .12-.59) and the risk difference was 12% (95% CI, 4.6%-20%) in favor of the TCZ group. With only a few studies available, there were no differences observed regarding side effects. Conclusions: Our results showed that mortality was 12% lower for COVID-19 patients treated with TCZ compared with those not treated with TCZ. The number needed to treat was 11, suggesting that for every 11 (severe) COVID-19 patients treated with TCZ, 1 death is prevented. These results require confirmation by randomized controlled trials.