Corticosteroids for the treatment of human infection with influenza virus: a systematic review and meta-analysis

Administration of corticosteroids to patients affected by influenza virus, especially pandemic avian influenza virus, although relatively common, remains controversial. A systematic review and meta-analysis was performed to assess the impact of corticosteroid treatment on outcomes of patients with influenza virus infection. The PubMed, EMBASE, Web of Science and Cochrane Library databases were searched up to February, 2015. Studies comparing corticosteroid treatment with no corticosteroid treatment in patients with influenza virus infection were included. The primary outcomes assessed were the association of mortality and nosocomial infection with corticosteroid treatment. Two authors independently extracted the data. ORs and weighted mean differences (WMDs) were used to describe dichotomous data and continuous data, respectively. Nineteen studies with 4916 patients were included in this meta-analysis. The results showed that corticosteroid treatment was significantly associated with mortality (OR 1.98, 95% CI 1.62-2.43, p < 0.00001) and nosocomial infection (OR 3.16, 95% CI 2.09-4.78, p < 0.00001). The durations of mechanical ventilation (WMD 3.82, 95% CI 1.49-6.15, p 0.001) and intensive-care unit stay (WMD 4.78, 95% CI 2.27-7.29, p 0.0002) were both markedly longer in the corticosteroid treatment group than in the control group. These findings suggest that routine steroid use may not be ideal for influenza virus infection. However, these results are derived from observational studies, with some important biases. They should be examined in future sufficiently powered randomized trials.