Since December 2019, several hospitals in Wuhan City, Hubei Province, have reported multiple cases of unexplained pneumonia with a history of travel to the South China seafood industry, believed to be an acute respiratory infectious disease triggered by the 2019 new coronavirus outbreak, also known as “New Coronavirus Pneumonia” (1–3).

According to existing case data, new coronavirus pneumonia mainly manifests as fever, dry cough, and fatigue (4, 5). A small number of patients present with nasal congestion, runny nose, diarrhea, and other upper respiratory and digestive tract symptoms. Severe cases often have difficulty breathing after 1 week, and rapidly progress to acute respiratory distress syndrome, septic shock, difficulty correcting metabolic acidosis, coagulation dysfunction, and multiple organ failure (6–8).

Corticosteroids are commonly used in the treatment of former coronavirus infections such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) and are now one of the treatment choices for new coronavirus infections (2019-nCoV) (9, 10). However, evidence for its effectiveness is inconclusive. The preliminary results of the RECOVERY trial show that the use of dexamethasone can reduce the 28-day mortality of coronavirus disease 2019 (COVID-19) patients, but only among patients who receive invasive mechanical ventilation (11). Systematic reviews, including randomized controlled trials (RCTs) and observational studies, have shown that corticosteroid use has a beneficial effect on reducing the mortality rate among severe patients with COVID-19 (12). This systematic review and meta-analysis included only RCTs to evaluate the effectiveness and safety of corticosteroids in the treatment of COVID-19.

The results of this systematic review and meta-analysis were different from those of previous studies. First, compared with standard care, corticosteroids do not reduce the mortality of hospitalized patients with COVID-19 within 28 days. Second, compared to the usual care group, the need for oxygen therapy was not significantly different in the corticosteroid group. However, the use of corticosteroids has significantly increased the discharge rate of patients with COVID-19. For other outcomes, including clinical benefit, early mortality, and adverse events, corticosteroiduse was not significantly different from standard care.

A previous prospective meta-analysis of seven randomized clinical trials was conducted. Patients with severe new coronary pneumonia treated with systemic corticosteroids (dexamethasone, hydrocortisone, or methylprednisolone) had a 28-day all-cause death rate that decreased by 20% compared to patients undergoing standard treatment or placebo (20).

Different results were found in this systematic review and meta-analysis and previous review articles published online by The Lancet. Researchers from the University of Edinburgh have found that corticosteroid therapy is not practical for patients with new coronary pneumonia (21). Similar treatments are not recommended for lung damage or shock caused by the new coronavirus (21, 22). Corticosteroids have been widely used to treat SARS (23, 24). However, the clinical guidelines issued by the World Health Organization on January 28, 2020, recommend that unless otherwise specified, corticosteroids should not be used for people who are not severely infected with the new coronavirus (25). Patients with new coronary pneumonia develop acute lung injury and acute respiratory distress syndrome caused by the host immune response (5). Corticosteroids can suppress lung inflammation, suppress immune response, and prevent it from clearing pathogens (21). This article compares the clinical data of corticosteroid treatment for the new coronavirus with other similar diseases. No clinical data have shown that corticosteroids are beneficial for treating of respiratory infections caused by viruses, such as SARS and MERS (21). Similar results were found in the RECOVERY trial, in which there was no indication that dexamethasone offered any advantage to patients who did not provide respiratory assistance at the time of randomization (11).

Although this meta-analysis and previous studies have shown that corticosteroids have no significant effect on the treatment of patients with COVID-19, however, a previous systematic review and RCTs found that compared with dexamethasone, methylprednisolone may have a better effect on the treatment of hospitalized patients with COVID-19 in terms of a lower mortality rate (9, 26). However, because of the few included studies, no firm conclusions could be drawn from these studies.

Corticosteroids are not used in treatment protocol to target virus but to attenuate the consequences of the infection. Several in vitro studies have shown that the dexamethasone and prednisolone are not directly acting as a potent antiviral, but used to minimize the cytokine storm in severe cases (27). Therefore, their impact may be not clear in RCTs including mild-to-moderate COVID-19 cases.

This meta-analysis has several limitations: (1) because there are few RCTs comparing corticosteroids and standard care, there are relatively few studies included in the meta-analysis, and there may be bias; (2) there are differences between each study, including the dose of the medication, the time of treatment, and follow-up duration; and (3) regarding the results of the duration of hospitalization, we did not find enough data in the included studies for meta-analysis.

Our meta-analysis indicates that, in contrast to previous studies, among hospitalized patients with COVID-19, the use of corticosteroids increases the hospital discharge rate. However, other clinical outcomes showed no differences with standard care, including 28-day mortality, need for oxygen support, duration of hospitalization, clinical improvements, early mortality, and adverse events.

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.

JL and JD designed the study and drafted the manuscript. YY, XY, and JS were involved in literature selection and data analysis. JL and HB revised the manuscript accordingly. HB was responsible for this project and commented on the manuscript accordingly. All authors have read and approved the final version of the manuscript.

The study was financially supported by the Key R&D Plan, Gansu Science and Technology Program (20YF2FA013) and the Innovation Base and Talent Plan, Gansu Science and Technology Program (20JR10FA666).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.