title: Sleep quality predicts quality of life in chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  Chronic obstructive pulmonary disease (COPD) patients may suffer from poor sleep and health-related quality of life. We hypothesized that disturbed sleep in COPD is correlated with quality of life.
  
  
  METHODS
  In 180 patients with COPD (forced expired volume in 1 second [FEV(1)] 47.6 ± 15.2% predicted, 77.8% male, aged 65.9 ± 11.7 years), we administered general (Health Utilities Index 3) and disease-specific (St George's Respiratory) questionnaires and an index of disturbed sleep (Pittsburgh Sleep Quality Index).
  
  
  RESULTS
  Overall scores indicated poor general (Health Utilities Index 3: 0.52 ± 0.38), disease- specific (St George's: 57.0 ± 21.3) quality of life and poor sleep quality (Pittsburgh 11.0 ± 5.4). Sleep time correlated with the number of respiratory and anxiety symptoms reported at night. Seventy-seven percent of the patients had Pittsburg scores >5, and the median Pittsburgh score was 12. On multivariate regression, the Pittsburgh Sleep Quality Index was an independent predictor of both the Health Utilities Index 3 and the St George's scores, accounting for 3% and 5%, respectively, of the scores. Only approximately 25% of the patients demonstrated excessive sleepiness (Epworth Sleepiness Scale >9).
  
  
  CONCLUSIONS
  Most patients with COPD suffer disturbed sleep. Sleep quality was correlated with general and disease-specific quality of life. Only a minority of COPD patients complain of being sleepy.
authors.affiliation: Department of Pulmonary and Critical Care, University of Maryland, Baltimore, MD, USA. sscharf@medicine.umaryland.edu
authors.forename: Steven M
authors.initials: SM
authors.lastname: Scharf
authors.forename: Nimrod
authors.initials: N
authors.lastname: Maimon
authors.forename: Tzahit
authors.initials: T
authors.lastname: Simon-Tuval
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Bernhard-Scharf
authors.forename: Haim
authors.initials: H
authors.lastname: Reuveni
authors.forename: Ariel
authors.initials: A
authors.lastname: Tarasiuk
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007557:Israel; D016018:Least-Squares Analysis; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D011788:Quality of Life; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012890:Sleep; D012893:Sleep Wake Disorders / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D013147:Spirometry; D011795:Surveys and Questionnaires