title: Overlap syndrome of asthma and COPD predicts low quality of life.
abstract: BACKGROUND
  In clinical practice, patients whose airway disease shares features of both asthma and chronic obstructive pulmonary disease (COPD) remain poorly recognized.
  
  
  METHODS
  The study population consisted of 1546 patients with a diagnosis of asthma or COPD or both. Based on patient-reported outcomes and retrospective medical record data, the study population was divided into three groups: ( 1 ) asthma only, ( 2 ) COPD only, and ( 3 ) both asthma and COPD (overlap syndrome group). We evaluated patient characteristics associated with health-related quality of life (HRQoL).
  
  
  RESULTS
  In many respects, the overlap group fell between the asthma and COPD groups. In the overlap group, however, HRQoL was the poorest of all. In the logistic regression model, with the asthma group as the reference, both the overlap and the COPD group showed higher risk for low HRQoL [odd ratio (OR): 1.9; 95% confidence interval (CI): 1.2-3.2; and OR: 1.8, 95% CI: 1.0-3.2; respectively]. In addition, female gender, obesity, duration of disease, disability pension, and coexisting cardiovascular disease were associated with low HRQoL across the study population.
  
  
  CONCLUSIONS
  Patients with overlapping asthma and COPD differed from those patients with asthma or COPD only. Overlap syndrome was associated with low HRQoL.
authors.affiliation: Department of Allergology, Skin and Allergy Hospital, Helsinki, Finland. paula.kauppi@hus.fi
authors.forename: Paula
authors.initials: P
authors.lastname: Kauppi
authors.forename: Henna
authors.initials: H
authors.lastname: Kupiainen
authors.forename: Ari
authors.initials: A
authors.lastname: Lindqvist
authors.forename: Lauri
authors.initials: L
authors.lastname: Tammilehto
authors.forename: Maritta
authors.initials: M
authors.lastname: Kilpeläinen
authors.forename: Vuokko L
authors.initials: VL
authors.lastname: Kinnula
authors.forename: Tari
authors.initials: T
authors.lastname: Haahtela
authors.forename: Tarja
authors.initials: T
authors.lastname: Laitinen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001249:Asthma / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D015897:Comorbidity; D004651:Employment / Q000706:statistics & numerical data; D005260:Female; D005387:Finland / Q000453:epidemiology; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D010415:Pensions / Q000706:statistics & numerical data; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology*; D011788:Quality of Life; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013577:Syndrome; D014797:Vital Capacity / Q000502:physiology