title: Do corticosteroids reduce the mortality of influenza A (H1N1) infection? A meta-analysis.
abstract: BACKGROUND
  Corticosteroids are used empirically in influenza A (H1N1) treatment despite lack of clear evidence for effective treatment. This study aims to assess the efficacy of corticosteroids treatment for H1N1 infection.
  
  
  METHODS
  Systematic review and meta-analysis were used to estimate the efficacy of corticosteroids for the prevention of mortality in H1N1 infection. Databases searched included MEDLINE, EMBASE, PubMed, Cochrane Central Register of Controlled Clinical Trials and so on, and bibliographies of retrieved articles, from April 2009 to October 2014. We included both cohort studies and case-control studies reported in English or Chinese that compared treatment effects between corticosteroids and non-corticosteroids therapy in inpatients with H1N1 virus infection. Cohort studies employed mortality as outcome, and case-control studies employed deaths as cases and survivors as controls; both were assessed in this meta-analysis.
  
  
  RESULTS
  In total twenty-three eligible studies were included. Both cohort studies (nine studies, n = 1,405) and case-control studies (14 studies, n = 4,700) showed a similar trend toward increased mortality (cohort studies relative risk was 1.85 with 95% confidence interval (CI) 1.46 to 2.33; case-control studies odds ratio was 4.22 with 95% CI 3.10 to 5.76). The results from both subgroup analyses and sensitive analyses were consistent with each other, showing that steroid treatment is associated with mortality. However, considering the fact that corticosteroids were tend to be used in sickest case-patients and heterogeneity was observed between studies, we cannot make a solid conclusion.
  
  
  CONCLUSIONS
  Available evidence did not support the use of corticosteroids as standard care for patients with severe influenza. We conclude that further research is required.
authors.affiliation: Beijing Center for Disease Prevention and Control (CDC), No. 16 He Pingli Middle Street, Dongcheng District, Beijing, 100013, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA, 70112, USA.|School of Food Science, Guangdong Pharmaceutical University, Zhongshan, 528458, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Sun
authors.affiliation: School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA, 70112, USA.
authors.forename: Erik R
authors.initials: ER
authors.lastname: Svendsen
authors.affiliation: School of Environment and Sustainability, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
authors.forename: Song
authors.initials: S
authors.lastname: Tang
authors.affiliation: School of Public Health and Community Medicine, The University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Raina C
authors.initials: RC
authors.lastname: MacIntyre
authors.affiliation: Beijing Center for Disease Prevention and Control (CDC), No. 16 He Pingli Middle Street, Dongcheng District, Beijing, 100013, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yang
authors.affiliation: Beijing Center for Disease Prevention and Control (CDC), No. 16 He Pingli Middle Street, Dongcheng District, Beijing, 100013, China.
authors.forename: Daitao
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Beijing Center for Disease Prevention and Control (CDC), No. 16 He Pingli Middle Street, Dongcheng District, Beijing, 100013, China. bjcdcxm@126.com.
authors.forename: Quanyi
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D015331:Cohort Studies; D003131:Combined Modality Therapy; D016638:Critical Illness; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000188:drug therapy* / Q000401:mortality / Q000628:therapy; D016017:Odds Ratio; D012121:Respiration, Artificial
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents