title: Hospitalization with acute exacerbation of chronic obstructive pulmonary disease and associated health resource utilization: a population-based Danish cohort study.
abstract: OBJECTIVE
  Health resource utilization (HRU) and outcomes associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are not well described. Therefore, a population-based cohort study was conducted to characterize patients hospitalized with AECOPD with regard to HRU, mortality, recurrence, and predictors of readmission with AECOPD.
  
  
  METHODS
  Using Danish healthcare databases, this study identified COPD patients with at least one AECOPD hospitalization between 2005-2009 in Northern Denmark. Hospitalized AECOPD patients' HRU, in-hospital mortality, 30-day, 60-day, 90-day, and 180-day post-discharge mortality and recurrence risk, and predictors of readmission with AECOPD in the year following study inclusion were characterized.
  
  
  RESULTS
  This study observed 6612 AECOPD hospitalizations among 3176 prevalent COPD patients. Among all AECOPD hospitalizations, median length of stay was 6 days (interquartile range [IQR] 3-9 days); 5 days (IQR 3-9) among those without ICU stay and 11 days (IQR 7-20) among the 8.6% admitted to the ICU. Mechanical ventilation was provided to 193 (2.9%) and non-invasive ventilation to 479 (7.2%) admitted patients. In-hospital mortality was 5.6%. Post-discharge mortality was 4.2%, 7.8%, 10.5%, and 17.4% at 30, 60, 90, and 180 days, respectively. Mortality and readmission risk increased with each AECOPD hospitalization experienced in the first year of follow-up. Readmission at least twice in the first year of follow-up was observed among 286 (9.0%) COPD patients and was related to increasing age, male gender, obesity, asthma, osteoporosis, depression, myocardial infarction, diabetes I and II, any malignancy, and hospitalization with AECOPD or COPD in the prior year.
  
  
  CONCLUSIONS
  The study included only hospitalized AECOPD patients among prevalent COPD patients. Furthermore, information was lacking on clinical variables.
  
  
  CONCLUSIONS
  These findings indicate that AECOPD hospitalizations are associated with substantial mortality and risk of recurrence.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark. saj@dce.au.dk
authors.forename: Sigrun A
authors.initials: SA
authors.lastname: Johannesdottir
authors.forename: Christian F
authors.initials: CF
authors.lastname: Christiansen
authors.forename: Martin B
authors.initials: MB
authors.lastname: Johansen
authors.forename: Morten
authors.initials: M
authors.lastname: Olsen
authors.forename: Xiao
authors.initials: X
authors.lastname: Xu
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Parker
authors.forename: Nestor A
authors.initials: NA
authors.lastname: Molfino
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Lash
authors.forename: Jon P
authors.initials: JP
authors.lastname: Fryzek
mesh_terms: D000208:Acute Disease; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay / Q000191:economics / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data; D029424:Pulmonary Disease, Chronic Obstructive / Q000191:economics* / Q000401:mortality; D012008:Recurrence; D012042:Registries; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D017678:Sex Distribution