title: Assisted ventilation in COPD - association between previous hospitalizations and mortality.
abstract: BACKGROUND
  In general, previous studies have shown an association between prior exacerbations and mortality in COPD, but this association has not been demonstrated in the subpopulation of patients in need of assisted ventilation. We examined whether previous hospitalizations were independently associated with mortality among patients with COPD ventilated for the first time.
  
  
  METHODS
  In the Danish National Patient Registry, we established a cohort of patients with COPD ventilated for the first time from 2003 to 2011 and previously medicated for obstructive airway diseases. We assessed the number of hospitalizations for COPD in the preceding year, age, sex, comorbidity, mode of ventilation, survival to discharge, and days to death beyond discharge.
  
  
  RESULTS
  The cohort consisted of 6,656 patients of whom 66% had not been hospitalized for COPD in the previous year, 18% once, 8% twice, and 9% thrice or more. In-hospital mortality was 45%, and of the patients alive at discharge, 11% died within a month and 39% within a year. In multivariate models, adjusted for age, sex, mode of ventilation, and comorbidity, odds ratios for in-hospital death were 1.26 (95% confidence interval [CI]: 1.11-1.44), 1.43 (95% CI: 1.19-1.72), and 1.56 (95% CI: 1.30-1.87) with one, two, and three or more hospitalizations, respectively. Hazard ratios for death after discharge from hospital were 1.32 (95% CI: 1.19-1.46), 1.76 (95% CI: 1.52-2.02), and 2.07 (95% CI: 1.80-2.38) with one, two, and three or more hospitalizations, respectively.
  
  
  CONCLUSIONS
  Preceding hospitalizations for COPD are associated with in-hospital mortality and after discharge in the subpopulation of patients with COPD with acute exacerbation treated with assisted ventilation for the first time.
authors.affiliation: Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; Department of Anaesthesia and Intensive Care, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Anne Pernille
authors.initials: AP
authors.lastname: Toft-Petersen
authors.affiliation: Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; Department of Health, Science and Technology, Aalborg University, Aalborg, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.affiliation: Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; Department of Respiratory Medicine, Aalborg University Hospital, Denmark.
authors.forename: Ulla Møller
authors.initials: UM
authors.lastname: Weinreich
authors.affiliation: Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; Department of Anaesthesia and Intensive Care, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Bodil Steen
authors.initials: BS
authors.lastname: Rasmussen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003718:Denmark; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D016017:Odds Ratio; D010351:Patient Discharge; D010359:Patient Readmission; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D012042:Registries; D012121:Respiration, Artificial / Q000009:adverse effects / Q000401:mortality*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: artificial; chronic obstructive; critical care; hospital mortality; patient readmission; pulmonary disease; respiration