title: Relationship Between Severity Classification of Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Clinical Outcomes in Hospitalized Patients.
abstract: BACKGROUND
  Limited data are available regarding the impact of the potential validation of the Canadian Thoracic Society (CTS) guidelines recommendations in classifying patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in simple and complex. The aim of the present study was to assess the CTS recommendations regarding risk stratification on clinical outcomes among patients hospitalized with an AECOPD.
  
  
  METHODS
  We developed a retrospective cohort study of patients admitted to one tertiary hospital with a diagnosis of AECOPD. The main clinical outcome was the percentage of treatment failure. Secondary outcomes were 30-day, 90-day, and 1-year readmission and mortality rate, length of stay in hospital, intensive care unit (ICU) admission rate, time to readmission, and time to death. Multivariate analyses were performed using 1-year mortality rate as the dependent measures.
  
  
  RESULTS
  One hundred forty-three patients composed the final study population, most of them (106 [74.1%)] classified as complex acute exacerbation (C-AE) of COPD. C-AE patients had similar rate of treatment failure compared with simple acute exacerbation (S-AE) of COPD (31.1% vs. 27%; p = 0.63). There were no differences regarding the length of stay in hospital, ICU admission rate, and 30-day, 90-day, and 1-year readmission rate. C-AE patients had faster declined measures on time to death (691.6 ± 430 days vs. 998.1 ± 355 days; p = 0.02). In the multivariate analysis, after adjusting for comorbidity, lung function and previous treatment, C-AE patients had a significant higher mortality at one year (Odds Ratio [OR] = 4.9 (Confidence Interval [CI] 95%: 1.16-21); p = 0.031).
  
  
  CONCLUSIONS
  In hospitalized patients with an AECOPD, CTS classification, according to the presence of risk factors, was not associated with worse short-term clinical outcomes although it is related with long-term mortality.
authors.affiliation: Servicio de Neumología. Instituto de Investigación Biomédica de A Coruña (INIBIC), Complejo Hospitalario Universitario de A Coruña (CHUAC), Sergas. Universidade da Coruña (UDC).
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Marcos
authors.affiliation: Respiratory Medicine, Hospital Lucus Augusti, Lugo.
authors.forename: Pilar
authors.initials: P
authors.lastname: Sanjuán
authors.affiliation: Respiratory Medicine, Hospital Clinic de Barcelona.
authors.forename: Arturo
authors.initials: A
authors.lastname: Huerta
authors.affiliation: Respiratory Medicine, CHU A Coruña, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Nieto-Codesido
authors.affiliation: Internal Medicine, Complejo Hospitalario Universitario de Ferrol.
authors.forename: Lucía
authors.initials: L
authors.lastname: Ferreira-Gonzalez
authors.affiliation: Servei de Pneumologia, Hospital Santa Creu i Sant Pau, Barcelona.
authors.forename: Oriol
authors.initials: O
authors.lastname: Sibila
authors.affiliation: Department of Medicine, Division of Pulmonary and Critical Care Medicine, South Texas Veterans Health Care System Audie L Murphy VA Hospital and the University of Texas Health Science Center at San Antonio.
authors.forename: Marcos I
authors.initials: MI
authors.lastname: Restrepo
keywords: copd; exacerbation; guidelines; hospitalization