RT Journal Article
SR Electronic
T1 Relationship between quality of life and clinical status in asthma: a factor analysis
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 287
OP 291
DO 10.1183/09031936.04.00064204
VO 23
IS 2
A1 E.F. Juniper
A1 M.E. Wisniewski
A1 F.M. Cox
A1 A.H. Emmett
A1 K.E. Nielsen
A1 P.M. O'Byrne
YR 2004
UL http://erj.ersjournals.com/content/23/2/287.abstract
AB Many studies have shown that correlation between clinical asthma status and asthma-specific quality of life is only weak to moderate. However, this relationship has never been explored to determine whether the weakness is due to noise of measurement or whether quality of life is a distinct component of asthma health status. With a database from three clinical trials (n=763), factor analysis was used to explore the relationships between quality of life, measured by the Asthma Quality of Life Questionnaire (AQLQ), and conventional measures of asthma clinical status (symptoms, airway calibre and rescue β2‐agonist use). The analysis revealed that although patients with severe, poorly controlled asthma tend to have worse quality of life than milder, well-controlled patients, overall asthma health status has four components (factors): asthma-specific quality of life; airway calibre; daytime symptoms and daytime β2‐agonist use, and night-time symptoms and night-time β2‐agonist use. The clean loading of all 21 outcomes onto four distinct and clinically identifiable factors suggests that, although some weakness of correlation between clinical indices and quality of life may be due to noise of measurement, it is mainly attributable to asthma health status being composed of distinct components. This study was supported by GlaxoSmithKline R&D.