title: Age and gender adjusted comparison of clinical features between severe cases infected with H7N9 and H1N1pdm influenza A in Jiangsu Province, China.
abstract: BACKGROUND
  Influenza H7N9 and H1N1pdm can cause severe human infections. It is important to investigate the distinguishing clinical features between these two diseases. Several studies have compared the differences in general, however, age and gender adjusted comparisons may be more useful and informative to the health professionals.
  
  
  METHODS
  A total of 184 severe H1N1pdm patients and 37 severe H7N9 patients from Jiangsu Province were included in this analysis to perform age and gender adjusted comparison of clinical features.
  
  
  RESULTS
  After adjusting age and gender, no significant differences in chronic medical conditions or treatment were found between severely ill patients with H7N9 and H1N1pdm. Severely ill patients with H7N9 had significantly longer interval from onset of illness to neuraminidase inhibitor treatment and to death. They were more likely to have complications such as acute respiratory distress syndrome (ARDS), liver and renal dysfunctions, and had a significantly higher risk of death.
  
  
  CONCLUSIONS
  Our results suggests that age and gender should be adjusted as important confounding factors when comparing the clinical features between severe H7N9 and H1N1pdm patients to avoid any misunderstanding regarding the differences between these two diseases particularly in terms of clinical severity and prognosis.
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Xiang
authors: X
authors: Huo
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Ke
authors: K
authors: Xu
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Qigang
authors: Q
authors: Dai
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Xian
authors: X
authors: Qi
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Huiyan
authors: H
authors: Yu
authors: Department of Acute Infectious Disease, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China, 210009.
authors: Changjun
authors: C
authors: Bao
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D064766:Influenza A Virus, H7N9 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000150:complications / Q000473:pathology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D011379:Prognosis; D012737:Sex Factors; D055815:Young Adult