title: Characterisation of exacerbation risk and exacerbator phenotypes in the POET-COPD trial.
abstract: BACKGROUND
  Data examining the characteristics of patients with frequent exacerbations of chronic obstructive pulmonary disease (COPD) and associated hospitalisations and mortality are scarce.
  
  
  METHODS
  Post-hoc analysis of the Prevention Of Exacerbations with Tiotropium in COPD (POET-COPD) trial, targeting exacerbations as the primary endpoint. Patients were classified as non-, infrequent, and frequent exacerbators (0, 1, or ≥ 2 exacerbations during study treatment), irrespective of study treatment. A multivariate Cox regression model assessed the effect of covariates on time to first exacerbation.
  
  
  RESULTS
  In total, 7376 patients were included in the analysis: 63.5% non-exacerbators, 22.9% infrequent, 13.6% frequent exacerbators. Factors significantly associated with exacerbation risk were age, sex, body mass index, COPD duration and severity, smoking history, baseline inhaled corticosteroid use, and preceding antibiotic or systemic corticosteroid courses. Frequent exacerbators had greater severity and duration of COPD, received more pulmonary medication, and ≥ 2 systemic corticosteroid or antibiotic courses in the preceding year, and were more likely to be female and ex-smokers. The small proportion of frequent exacerbators (13.6%) accounted for 56.6% of exacerbation-related hospitalisations, which, overall, were associated with a three-fold increase in mortality.
  
  
  CONCLUSIONS
  The frequent exacerbator phenotype was closely associated with exacerbation-related hospitalisations, and exacerbation-related hospitalisations were associated with poorer survival.
  
  
  BACKGROUND
  NCT00563381; Study identifier: BI 205.389.
authors.forename: Kai M
authors.initials: KM
authors.lastname: Beeh
authors.forename: Thomas
authors.initials: T
authors.lastname: Glaab
authors.forename: Susanne
authors.initials: S
authors.lastname: Stowasser
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schmidt
authors.forename: Leonardo M
authors.initials: LM
authors.lastname: Fabbri
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Rabe
authors.affiliation: University Medical Center Giessen and Marburg, Philipps-Universität Marburg, Baldingerstrasse, D 35043 Marburg, Germany. claus.vogelmeier@med.uni-marburg.de.
authors.forename: Claus F
authors.initials: CF
authors.lastname: Vogelmeier
mesh_terms: D000280:Administration, Inhalation; D000368:Aged; D000369:Aged, 80 and over; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use; D018450:Disease Progression; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000401:mortality; D012044:Regression Analysis; D012307:Risk Factors; D000068299:Salmeterol Xinafoate; D012602:Scopolamine Derivatives / Q000008:administration & dosage / Q000627:therapeutic use*; D012720:Severity of Illness Index; D015996:Survival Rate; D000069447:Tiotropium Bromide; D016896:Treatment Outcome
chemical_list: D012602:Scopolamine Derivatives; D000068299:Salmeterol Xinafoate; D000420:Albuterol; D000069447:Tiotropium Bromide