title: Characterisation and prognosis of undiagnosed chronic obstructive pulmonary disease patients at their first hospitalisation.
abstract: BACKGROUND
  Under-diagnosis of COPD is an important unmet medical need. We investigated the characteristics and prognosis of hospitalised patients with undiagnosed COPD.
  
  
  METHODS
  The PAC-COPD cohort included 342 COPD patients hospitalised for the first time for an exacerbation of COPD (2004-2006). Patients were extensively characterised using sociodemographic, clinical and functional variables, and the cohort was followed-up through 2008. We defined "undiagnosed COPD" by the absence of any self-reported respiratory disease and regular use of any pharmacological respiratory treatment.
  
  
  RESULTS
  Undiagnosed COPD was present in 34% of patients. They were younger (mean age 66 vs. 68 years, p = 0.03), reported fewer symptoms (mMRC dyspnoea score, 2.1 vs. 2.6, p < 0.01), and had a better health status (SGRQ total score, 29 vs. 40, p < 0.01), milder airflow limitation (FEV1% ref., 59% vs. 49%, p < 0.01), and fewer comorbidities (two or more, 40% vs. 56%, p < 0.01) when compared with patients with an established COPD diagnosis. Three months after hospital discharge, 16% of the undiagnosed COPD patients had stopped smoking (vs. 5%, p = 0.019). During follow-up, annual hospitalisation rates were lower in undiagnosed COPD patients (0.14 vs. 0.25, p < 0.01); however, this difference disappeared after adjustment for severity. Mortality was similar in both groups.
  
  
  CONCLUSIONS
  Undiagnosed COPD patients have less severe disease and lower risk of re-hospitalisation when compared with hospitalised patients with known COPD.
authors.forename: Eva
authors.initials: E
authors.lastname: Balcells
authors.forename: Elena
authors.initials: E
authors.lastname: Gimeno-Santos
authors.forename: Jordi
authors.initials: J
authors.lastname: de Batlle
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Ramon
authors.forename: Esther
authors.initials: E
authors.lastname: Rodríguez
authors.forename: Marta
authors.initials: M
authors.lastname: Benet
authors.forename: Eva
authors.initials: E
authors.lastname: Farrero
authors.forename: Antoni
authors.initials: A
authors.lastname: Ferrer
authors.forename: Stefano
authors.initials: S
authors.lastname: Guerra
authors.forename: Jaume
authors.initials: J
authors.lastname: Ferrer
authors.forename: Jaume
authors.initials: J
authors.lastname: Sauleda
authors.forename: Joan A
authors.initials: JA
authors.lastname: Barberà
authors.forename: Àlvar
authors.initials: À
authors.lastname: Agustí
authors.forename: Robert
authors.initials: R
authors.lastname: Rodriguez-Roisin
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gea
authors.forename: Josep M
authors.initials: JM
authors.lastname: Antó
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Doctor Aiguader 88, 08003 Barcelona, Spain. jgarcia@creal.cat.
authors.forename: Judith
authors.initials: J
authors.lastname: Garcia-Aymerich
mesh_terms: D000368:Aged; D015897:Comorbidity; D004417:Dyspnea; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006304:Health Status; D006760:Hospitalization; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality*; D057566:Self Report; D012720:Severity of Illness Index; D016540:Smoking Cessation / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D064424:Tobacco Use