title: Factors that influence disease-specific quality of life or health status in patients with COPD: a review and meta-analysis of Pearson correlations.
abstract: BACKGROUND
  A major goal in the management of chronic obstructive pulmonary disease (COPD) is to ensure that the burden of the disease for patients with COPD is limited and that patients will have the best possible quality of life.
  
  
  OBJECTIVE
  To explore all the possible factors that could influence disease-specific quality of life and health status in patients with COPD.
  
  
  METHODS
  A systematic review of the literature and a meta-analysis were performed to explore the factors that could have a positive or negative effect on quality of life and/or health status in patients with COPD.
  
  
  RESULTS
  Quality of life and health status are determined by certain factors included gender, disease severity indices, lung function parameters, body mass index, smoking, symptoms, co-morbidity, depression, anxiety, and exacerbations. Factors such as dyspnoea, depression, anxiety and exercise tolerance were found to be more correlated with health status than the widely used spirometric values. Forced expiratory volume in one second had a weak to modest Pearson weighted correlation coefficient which ranged from -0.110 to -0.510 depending on the questionnaire used.
  
  
  CONCLUSIONS
  The broad range of determining factors suggests that, in order to reach the management goals, health status should be measured in addition to lung function in patients with COPD.
authors.affiliation: University Medical Center, University of Groningen, Groningen, The Netherlands. pdkapa@yahoo.gr
authors.forename: Ioanna
authors.initials: I
authors.lastname: Tsiligianni
authors.forename: Janwillem
authors.initials: J
authors.lastname: Kocks
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tzanakis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Siafakas
authors.forename: Thys
authors.initials: T
authors.lastname: van der Molen
mesh_terms: D006304:Health Status; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis; D011788:Quality of Life