title: Hospitalized exacerbations of COPD: risk factors and outcomes in the ECLIPSE cohort.
abstract: OBJECTIVE
  Exacerbations of COPD requiring hospital admission have important clinical and societal implications. We sought to investigate the incidence, recurrence, risk factors, and mortality of patients with COPD exacerbations requiring hospital admission compared with those without hospital admission during 3-year follow-up. Patients with COPD (N = 2,138) were identified from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) observational cohort.
  
  
  METHODS
  An analysis of time to first event of hospital admission was performed using Kaplan-Meier curves and Cox proportional hazard regression adjusting for possible confounders.
  
  
  RESULTS
  Of the 2,138 patients, 670 (31%) reported a total of 1,452 COPD exacerbations requiring hospital admission during the study period; 313 patients (15%) reported multiple events. A prior history of exacerbation of COPD requiring hospital admission was the factor associated with the highest risk of a new hospitalization for exacerbation (hazard ratio, 2.71; 95% CI, 2.24-3.29; P < .001). Other risk factors included more severe airflow limitation, poorer health status, older age, radiologic evidence of emphysema, and higher WBC count. Having been hospitalized for exacerbation significantly increased the risk of mortality (P < .001).
  
  
  CONCLUSIONS
  Exacerbations of COPD requiring hospital admission occur across all stages of airflow limitation and are a significant prognostic factor of reduced survival across all COPD stages. Patients with COPD at a high risk for hospitalization can be identified by their past history for similar events, and other factors, including the severity of airflow limitation, poor health status, age, presence of emphysema, and leukocytosis.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT00292552; URL: www.clinicaltrials.gov.
authors.affiliation: Respiratory Epidemiology, GlaxoSmithKline R&D, Uxbridge, England.
authors.forename: Hana
authors.initials: H
authors.lastname: Müllerova
authors.affiliation: Audie L. Murphy Hospital, South Texas Veterans Health Care System, San Antonio, TX; Division of Pulmonary Diseases/Critical Care Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Diego J
authors.initials: DJ
authors.lastname: Maselli
authors.affiliation: Respiratory Medicines Development Center, GlaxoSmithKline, Research Triangle Park, NC.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Locantore
authors.affiliation: Gentofte, Hellerup, Denmark; Respiratory Research Group, Manchester Academic Health Science Centre, University of Manchester, Manchester, England.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Vestbo
authors.affiliation: Centre of Inflammation and Tissue Repair, University College London, London, England.
authors.forename: John R
authors.initials: JR
authors.lastname: Hurst
authors.affiliation: Centre for Respiratory Medicine, University College London, London, England.
authors.forename: Jadwiga A
authors.initials: JA
authors.lastname: Wedzicha
authors.affiliation: Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Per
authors.initials: P
authors.lastname: Bakke
authors.affiliation: Thorax Institute, Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain; FISIB, CIBER Enfermedades Respiratorias, Mallorca, Spain.
authors.forename: Alvar
authors.initials: A
authors.lastname: Agusti
authors.affiliation: Audie L. Murphy Hospital, South Texas Veterans Health Care System, San Antonio, TX; Division of Pulmonary Diseases/Critical Care Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX. Electronic address: anzueto@uthscsa.edu.
authors.forename: Antonio
authors.initials: A
authors.lastname: Anzueto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D015994:Incidence; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D012008:Recurrence; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014481:United States / Q000453:epidemiology