title: Is Acute Exacerbation of COPD (AECOPD) Related to Viral Infection Associated with Subsequent Mortality or Exacerbation Rate?
abstract: BACKGROUND
  There is a growing interest in better defining risk factors associated with increased susceptibility to exacerbation in patients with COPD.
  
  
  BACKGROUND
  The aim of the study was to determine whether identification of a respiratory virus during a severe acute exacerbation of COPD (AECOPD) increases the risk of subsequent exacerbations and mortality during a one-year followup.
  
  
  METHODS
  Secondary analysis of 86 COPD patients admitted for AECOPD between June 2007 and December 2008 at Geneva's University Hospital who were followed up for 1 year. Fifty-one percent of index AECOPD were related to viral infection. Rate of AECOPD, time to next AECOPD, and all-cause mortality were compared between patients with vs without viral index AECOPD.
  
  
  RESULTS
  Eighty-one cases were included in this secondary follow-up analysis. Mean exacerbation rate was 1.9 AECOPD per person-year for patients with viral index AECOPD vs 4.0 AECOPD per person year for those with non-viral index AECOPD. Incidence rate ratio (IRR) for subsequent AECOPD during one year follow up was lower for patients with viral index AECOPD (IRR 0.57; [CI 95% 0.39-0.84]), after controlling for previous exacerbations, and was strongly associated with the number of exacerbations in the year preceding the index AECOPD. During the one-year follow-up period, 16 patients (19%) died. In a Cox regression model, patients with a proven viral infection did not have a higher mortality (HR 0.56 [CI 95% 0.20 -1.58]).
  
  
  CONCLUSIONS
  Viral AECOPD was not associated with a higher rate of subsequent exacerbations or mortality during the following year.
authors.affiliation: Department of Internal Medicine and University of Geneva, La Tour Hospital, Geneva, Switzerland.
authors.forename: Omar
authors.initials: O
authors.lastname: Kherad
authors.affiliation: Division of Pulmonary Diseases, Geneva's University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Pierre-Olivier
authors.initials: PO
authors.lastname: Bridevaux
authors.affiliation: Central Laboratory of Virology, Division of Infectious Diseases, Geneva's University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Kaiser
authors.affiliation: Division of Pulmonary Diseases, Geneva's University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Janssens
authors.affiliation: Department of Community, Primary Care and Emergency Medicine, Geneva's University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Olivier T
authors.initials: OT
authors.lastname: Rutschmann
keywords: COPD; exacerbation; phenotype; virus.