title: Health status, dyspnea, lung function and exercise capacity in patients with chronic obstructive pulmonary disease.
abstract: METHODS
  A secondary hospital outside Oslo.
  
  
  OBJECTIVE
  To assess relationships between health status and measures of dyspnea, lung function and exercise capacity in patients with chronic obstructive pulmonary disease (COPD), to identify dimensions where lung-specific instruments associate and discriminate better than general measures.
  
  
  METHODS
  We assessed health status in 59 out-patients with COPD, using the following instruments: Short Form 36 (SF-36)-a general health status measure, Respiratory Quality of Life Questionnaire (RQLQ)-a lung-specific measure, the Karnofsky performance scale, and a rating scale. All patients rated their dyspnea and had spirometry and exercise capacity measured.
  
  
  RESULTS
  Mean (SD) patient age was 57.3 (9.7) years, FEV1 47% (15%) of predicted, 6 minute walk distance 503 m (122 m). Dyspnea was the strongest predictor for health status. Both SF-36 and RQLQ had dimensions associating well with dyspnea and exercise capacity. The associations with FEV1 ranged from none to moderate.
  
  
  CONCLUSIONS
  All RQLQ scales had a moderate to substantial association with indices of dyspnea and exercise capacity, while the SF-36 associated well only in dimensions related to physical health. The general measure has a broader scope and complements the lung-specific measure. These findings support the construct validity of both the SF-36 and the RQLQ, and justify using a general measure to supplement a lung-specific measure.
authors.affiliation: HELTEF Foundation for Health Services Research, Nordbyhagen, Norway. knut.stavem@klinmed.uio.no
authors.forename: K
authors.initials: K
authors.lastname: Stavem
authors.forename: J
authors.initials: J
authors.lastname: Boe
authors.forename: J
authors.initials: J
authors.lastname: Erikssen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004417:Dyspnea / Q000503:physiopathology*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006304:Health Status; D006801:Humans; D017567:Karnofsky Performance Status; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires