title: Co-morbidities are the key nominators of the health related quality of life in mild and moderate COPD.
abstract: BACKGROUND
  Co-morbidities are common in chronic obstructive pulmonary disease (COPD). We assessed the contribution of common co-morbidities on health related quality of life (HRQoL) among COPD patients.
  
  
  METHODS
  Using both generic (15D) and respiratory-specific (AQ20) instruments, HRQoL was assessed in a hospital based COPD population (N = 739, 64% males, mean age 64 years, SD 7 years) in this observational study with inferential analysis. The prevalence of their co-morbidities was compared with those of 5000 population controls. The patients represented all severity stages of COPD and the patterns of common concomitant disorders differed between patients.
  
  
  RESULTS
  Co-morbidities such as psychiatric conditions, alcohol abuse, cardiovascular diseases, and diabetes were more common among COPD patients than in age and gender matched controls. Psychiatric conditions and alcohol abuse were the strongest determinants of HRQoL in COPD and could be detected by both 15D (Odds Ratio 4.7 and 2.3 respectively) and AQ20 (OR 2.0 and 3.0) instruments. Compared to respiratory specific AQ20, generic 15D was more sensitive to the effects of comorbidities while AQ20 was slightly more sensitive for the low FEV1. FEV1 was a strong determinant of HRQoL only at more severe stages of disease (FEV1 < 40% of predicted). Poor HRQoL also predicted death during the next five years.
  
  
  CONCLUSIONS
  The results suggest that co-morbidities may impair HRQoL at an early stage of the disease, while bronchial obstruction becomes a significant determinant of HRQoL only in severe COPD.
authors.affiliation: Clinical Research Unit for Pulmonary Diseases and Division of Pulmonology, Helsinki University Central Hospital, Helsinki, Finland. jukka.koskela@helsinki.fi.
authors.forename: Jukka
authors.initials: J
authors.lastname: Koskela
authors.forename: Maritta
authors.initials: M
authors.lastname: Kilpeläinen
authors.forename: Henna
authors.initials: H
authors.lastname: Kupiainen
authors.forename: Witold
authors.initials: W
authors.lastname: Mazur
authors.forename: Harri
authors.initials: H
authors.lastname: Sintonen
authors.forename: Marike
authors.initials: M
authors.lastname: Boezen
authors.forename: Ari
authors.initials: A
authors.lastname: Lindqvist
authors.forename: Dirkje
authors.initials: D
authors.lastname: Postma
authors.forename: Tarja
authors.initials: T
authors.lastname: Laitinen
mesh_terms: D000368:Aged; D000437:Alcoholism / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D005541:Forced Expiratory Volume; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology; D011788:Quality of Life; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires