Sleep quality predicts quality of life in chronic obstructive pulmonary disease

Steven M Scharf^1*, Nimrod Maimon^2*, Tzahit Simon-Tuval³, Barbara J Bernhard-Scharf⁴, Haim Reuveni², Ariel Tarasiuk²

¹Department of Pulmonary and Critical Care, University of Maryland, Baltimore, MD, USA; ²Faculty of Health Sciences, Ben-Gurion University, Beersheba, Israel; ³Guilford Glazer School of Business and Management, Ben Gurion University, Beersheba, Israel; ⁴Mt. Washington Pediatric Hospital, Baltimore, MD, USA; The study was performed at the Soroka University Medical Center, Beer Sheva, Israel
*Drs Scharf and Maimon contributed equally to this manuscript.

Purpose: 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 [FEV₁] 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.
Keywords: COPD, quality of life, Pittsburgh Sleep Quality Index, St George’s Respiratory Questionnaire, Health Utilities Index, sleep quality