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

Abstract

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.

Keywords: corticosteroids; influenza A(H1N1)pdm09 virus; mortality; pneumonia.

Figure 1

Study flow diagram

Figure 2

Kaplan‐Meier survival curves for matched patients treated with low‐to‐moderate‐dose corticosteroids or with no corticosteroids (control), censored at 30 d. A, Including all the patients (n=530, log‐rank chi‐squared=10.48, P=.001), the 30‐day mortality in the low‐to‐moderate dose corticosteroid group and control group was 6.8% (18/265) and 14.7% (39/265), respectively. B, Including patients with PaO₂/FiO₂ <300 mm Hg (n=351, log‐rank chi‐squared=13.24, P<.001), the 30‐day mortality in the low‐to‐moderate‐dose corticosteroid group and control group was 8.1% (14/173) and 20.2% (36/178), respectively. C, Including patients with PaO₂/FiO₂ ≥300 mm Hg (n=179, log‐rank chi‐squared=0.17, P=.68), the 30‐day mortality in the low‐to‐moderate‐dose corticosteroid group and control group was 4.3% (4/92) and 3.4% (3/87), respectively

Figure 3

Kaplan‐Meier survival curves for matched patients treated with high‐dose corticosteroids or with no corticosteroids (control), censored at 30 d. A, Including all the patients (n=296, log‐rank chi‐squared=1.06, P=.30), the 30‐day mortality in the high‐dose corticosteroid group and control group was 17.6% (26/148) and 19.6% (29/148), respectively. B, Including patients with PaO₂/FiO₂ <300 mm Hg (n=256, log‐rank chi‐squared=1.33, P=.25), the 30‐day mortality in the high‐dose corticosteroids group and control group was 19.7% (25/127) and 22.5% (29/129), respectively