title: Chronic obstructive pulmonary disease stage and health-related quality of life. The Quality of Life of Chronic Obstructive Pulmonary Disease Study Group.
abstract: BACKGROUND
  The American Thoracic Society recently recommended that chronic obstructive pulmonary disease be staged on the basis of the percentage of predicted FEV1.
  
  
  OBJECTIVE
  To examine 1) the relation between the american Thoracic Society system for staging chronic obstructive pulmonary disease and health-related quality of life and 2) the effect of self-reported comorbid conditions on health-related quality of life.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Outpatient clinics of respiratory departments of four hospitals and one primary health care center in spain.
  
  
  METHODS
  321 consecutive male patients with chronic obstructive pulmonary disease.
  
  
  METHODS
  Functional respiratory impairment, FEV1, respiratory symptoms, and health-related quality of life. Respiratory symptoms and health-related quality of life were measured by using the Spanish version of the St. George's Respiratory Questionnaire and the Nottingham Health Profile.
  
  
  RESULTS
  Patient scores on the St. George's Respiratory Questionnaire were moderately to strongly associated with disease staging (r = 0.27 to 0.51). Compared with reference values, values for health-related quality of life for patients with stage I disease were substantially higher on the St. George's Respiratory Questionnaire (6 and 34; p < 0.001) and values for impairment were significantly greater in stage 1 patients with comorbid conditions (19 and 36; P = 0.001). At least one concomitant chronic condition was found in 84% of study patients. Comorbid conditions only partly influenced the observed pattern of deterioration of health-related quality of life with worsening stages of disease.
  
  
  CONCLUSIONS
  Staging criteria for chronic obstructive pulmonary disease based on percentage of predicted FEV1 separated groups of patients with varying degrees of impairment in health-related quality of life. Contrary to expectations, even patients with mild disease showed substantially compromised health-related quality of life. Comorbid conditions influenced the relation between chronic obstructive pulmonary disease and health-related quality of life.
authors.affiliation: Hospital de Badalona Germans Trias i Pujol, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ferrer
authors.forename: J
authors.initials: J
authors.lastname: Alonso
authors.forename: J
authors.initials: J
authors.lastname: Morera
authors.forename: R M
authors.initials: RM
authors.lastname: Marrades
authors.forename: A
authors.initials: A
authors.lastname: Khalaf
authors.forename: M C
authors.initials: MC
authors.lastname: Aguar
authors.forename: V
authors.initials: V
authors.lastname: Plaza
authors.forename: L
authors.initials: L
authors.lastname: Prieto
authors.forename: J M
authors.initials: JM
authors.lastname: Antó
mesh_terms: D015897:Comorbidity; D003430:Cross-Sectional Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012044:Regression Analysis; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires