title: Clinical characteristics and outcomes of H1N1-associated pneumonia among adults in South Korea.
abstract: BACKGROUND
  Pneumonia has been reported to be the most life-threatening complication of influenza virus infection.
  
  
  OBJECTIVE
  to describe clinical characteristics and determine risk factors for death among patients with H1N1-associated pneumonia.
  
  
  METHODS
  A retrospective cohort study included all adult patients diagnosed and treated with H1N1-associated pneumonia in 14 participating institutions between 1 May 2009 and 28 February 2010 in South Korea. Clinical outcomes were summarised and predictors for death evaluated through univariate and multivariate analysis.
  
  
  RESULTS
  A total of 269 adult patients with H1N1-associated pneumonia were diagnosed and treated. Hospital visits or admissions peaked in November 2009, coinciding with the peak in the 2009 H1N1 epidemic in South Korea. The patients' median age was 48 years; 143 were male. Most (n = 266, 98.9%) were admitted for treatment: 97 (36.1%) required intensive care and 28 (10.4%) needed mechanical ventilation. Despite the use of antiviral and antibacterial agents, 19 patients (7.1%) died. Risk factors predictive of death included presence of malignancy (aOR 12.0, 95%CI 2.8-51.5), and pneumonia severity index (PSI) score (aOR 1.03, 95%CI 1.01-1.04).
  
  
  CONCLUSIONS
  Deaths among adult patients with H1N1-associated pneumonia were not rare. Clinicians should be aware of the possibility of a poor prognosis among H1N1-associated pneumonia patients with underlying malignancy or high PSI score.
authors.affiliation: Department of Internal Medicine, Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: W-I
authors.initials: WI
authors.lastname: Choi
authors.forename: J-J
authors.initials: JJ
authors.lastname: Yim
authors.forename: J
authors.initials: J
authors.lastname: Park
authors.forename: S-C
authors.initials: SC
authors.lastname: Kim
authors.forename: M J
authors.initials: MJ
authors.lastname: Na
authors.forename: W-Y
authors.initials: WY
authors.lastname: Lee
authors.forename: S-B
authors.initials: SB
authors.lastname: Hong
authors.forename: H S
authors.initials: HS
authors.lastname: Choi
authors.forename: S H
authors.initials: SH
authors.lastname: Jang
authors.forename: W J
authors.initials: WJ
authors.lastname: Kim
authors.forename: K
authors.initials: K
authors.lastname: Jeon
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: J C
authors.initials: JC
authors.lastname: Choi
authors.forename: C-H
authors.initials: CH
authors.lastname: Lee
authors.forename: C H
authors.initials: CH
authors.lastname: Kim
authors.forename: J Y
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use; D016009:Chi-Square Distribution; D003422:Critical Care; D005260:Female; D006760:Hospitalization; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D007251:Influenza, Human / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy / Q000821:virology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy / Q000821:virology; D056910:Republic of Korea / Q000453:epidemiology; D012121:Respiration, Artificial; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000998:Antiviral Agents