title: Health-related quality of life and long-term prognosis in chronic hypercapnic respiratory failure: a prospective survival analysis.
abstract: BACKGROUND
  Health-related quality of life (HRQL) is considered as an important outcome parameter in patients with chronic diseases. This study aimed to assess the role of disease-specific HRQL for long-term survival in patients of different diagnoses with chronic hypercapnic respiratory failure (CHRF).
  
  
  METHODS
  In a cohort of 231 stable patients (chronic obstructive pulmonary disease (COPD), n = 98; non-COPD (obesity-hypoventilation syndrome, restrictive disorders, neuromuscular disorders), n = 133) with CHRF and current home mechanical ventilation (HMV), HRQL was assessed by the disease-specific Severe Respiratory Insufficiency (SRI) questionnaire and its prognostic value was prospectively evaluated during a follow-up of 2-4 years, using univariate and multivariate regression analysis.
  
  
  RESULTS
  HRQL was more impaired in COPD (mean +/- SD SRI-summary score (SRI-SS) 52.5 +/- 15.6) than non-COPD patients (67.6 +/- 16.4; p < 0.001). Overall mortality during 28.9 +/- 8.8 months of follow-up was 19.1% (31.6% in COPD, 9.8% in non-COPD). To identify the overall role of SRI, we first evaluated the total study population. SRI-SS and its subdomains (except attendance symptoms and sleep), as well as body mass index (BMI), leukocyte number and spirometric indices were associated with long-term survival (p < 0.01 each). Of these, SRI-SS, leukocytes and forced expiratory volume in 1 s (FEV1) turned out to be independent predictors (p < 0.05 each). More specifically, in non-COPD patients SRI-SS and most of its subdomains, as well as leukocyte number, were related to survival (p < 0.05), whereas in patients with COPD only BMI and lung function but not SRI were predictive.
  
  
  CONCLUSIONS
  In patients with CHRF and HMV, the disease-specific SRI was an overall predictor of long-term survival in addition to established risk factors. However, the SRI predominantly beared information regarding long-term survival in non-COPD patients, while in COPD patients objective measures of the disease state were superior. This on one hand highlights the significance of HRQL in the long-term course of patients with CHRF, on the other hand it suggests that the predictive value of HRQL depends on the underlying disease.
authors: Center for Pneumology, Donaustauf Hospital, Donaustauf, Germany. stephan.budweiser@klinik.uni-regensburg.de
authors: Stephan
authors: S
authors: Budweiser
authors: Andre P
authors: AP
authors: Hitzl
authors: Rudolf A
authors: RA
authors: Jörres
authors: Kathrin
authors: K
authors: Schmidbauer
authors: Frank
authors: F
authors: Heinemann
authors: Michael
authors: M
authors: Pfeifer
mesh_terms: D000368:Aged; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D006935:Hypercapnia / Q000175:diagnosis* / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000453:epidemiology; D011795:Surveys and Questionnaires; D016019:Survival Analysis