Effect of low-to-moderate-dose corticosteroids on mortality of hospitalized adolescents and adults with influenza A(H1N1)pdm09 viral pneumonia.

Background The effect of corticosteroids on influenza A(H1N1)pdm09 viral pneumonia patients remains controversial, and the impact of dosage has never been studied. Methods Using data of hospitalized adolescent and adult patients with influenza A(H1N1)pdm09 viral pneumonia, prospectively collected from 407 hospitals in mainland China, the effects of low-to-moderate-dose (25-150 mg d⁻¹) and high-dose (>150 mg d⁻¹) corticosteroids on 30-day mortality, 60-day mortality, and nosocomial infection were assessed with multivariate Cox regression and propensity score-matched case-control analysis. Results In total, 2141 patients (median age: 34 years; morality rate: 15.9%) were included. Among them, 1160 (54.2%) had PaO₂/FiO₂<300 mm Hg on admission, and 1055 (49.3%) received corticosteroids therapy. Corticosteroids, without consideration of dose, did not influence either 30-day or 60-day mortality. Further analysis revealed that, as compared with the no-corticosteroid group, low-to-moderate-dose corticosteroids were related to reduced 30-day mortality (adjusted hazard ratio [ aHR] 0.64 [95% CI 0.43-0.96, P=.033]). In the subgroup analysis among patients with PaO₂/FiO₂<300 mm Hg, low-to-moderate-dose corticosteroid treatment significantly reduced both 30-day mortality ( aHR 0.49 [95% CI 0.32-0.77]) and 60-day mortality ( aHR 0.51 [95% CI 0.33-0.78]), while high-dose corticosteroid therapy yielded no difference. For patients with PaO₂/FiO₂ ≥300 mm Hg, corticosteroids (irrespective of dose) showed no benefit and even increased 60-day mortality ( aHR 3.02 [95% CI 1.06-8.58]). Results were similar in the propensity model analysis. Conclusions Low-to-moderate-dose corticosteroids might reduce mortality of influenza A(H1N1)pdm09 viral pneumonia patients with PaO₂/FiO₂<300 mm Hg. Mild patients with PaO₂/FiO₂ ≥300 mm Hg could not benefit from corticosteroid therapy. [ABSTRACT FROM AUTHOR]