Corticosteroid Use in Influenza Increases Mortality, Infection Risk

Study findings posted online in Critical Care Medicine, show that corticosteroid use among individuals with influenza may increase both mortality and hospital-acquired infection.

“Corticosteroids may be beneficial in sepsis, but uncertainty remains over their effects in severe influenza,” study authors explained. “This systematic review updates the current evidence regarding corticosteroids in the treatment of influenza and examines the effect of dose on outcome.”

For the study, a team of researchers used electronic databases and trial registries in order to identify randomized controlled trials, quasi-experimental designs, and observational cohort studies reporting corticosteroid versus no corticosteroid treatment in individuals with influenza. Two of the researchers then assessed the studies for inclusion and used the Cochrane Risk of Bias tool (randomized controlled trials) or Newcastle-Ottawa Scale (observational studies) in order to identify bias.

“Where appropriate, we estimated the effect of corticosteroids by random-effects meta-analyses using the generic inverse variance method,” they noted. “Meta–regression analysis was used to assess the association of corticosteroid dose and mortality.”

Based off of their criteria, the research team identified 30 eligible studies—29 were observational and one was a randomized control trial.

According to the findings, 21 observational studies that were included in the meta-analysis of mortality suggested an adverse association with corticosteroid therapy (odds ratio, 3.90; 95% CI, 2.31–6.60; 15 studies; adjusted hazard ratio, 1.49; 95% CI, 1.09–2.02; six studies). The researchers noted that risk of bias assessment was consistent with potential confounding by indication. Further, there were increased odds of hospital-acquired infection in people treated with corticosteroids based of pooled analysis of seven studies (unadjusted odds ratio, 2.74; 95% CI, 1.51–4.95). Finally, the researchers found that meta-regression of the effect of dose on mortality did not reveal a clear association. They explained that the reported doses of corticosteroids in the studies they observed were high (mostly > 40 mg methylprednisolone [or equivalent] per day).

“Corticosteroid treatment in influenza is associated with increased mortality and hospital-acquired infection, but the evidence relates mainly to high corticosteroid doses and is of low quality with potential confounding by indication a major concern,” they concluded.

—Julie Gould  

Reference:

Lansbury LE, Rodrigo C, Leonardi-Bee Jo, Nguyen-Van-Tam J, Shen Lim W. Corticosteroids as adjunctive therapy in the treatment of influenza: an updated Cochrane systematic review and meta-analysis. Crit Care Med. 2020;48(2):e98-e106. doi:10.1097/CCM.0000000000004093.