Confirmatory factor analysis of the Epworth Sleepiness Scale (ESS) in patients with obstructive sleep apnoea

Smith, Simon S., Oei, Tian, Douglas, James, Brown, Ian, Jorgensen, Greg, & Andrews, Jonathan (2008) Confirmatory factor analysis of the Epworth Sleepiness Scale (ESS) in patients with obstructive sleep apnoea. Sleep Medicine, 9(7), pp. 739-744.

View at publisher


Background: The Epworth Sleepiness Scale (ESS [Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep 1991;14(6):540–5]) has been used frequently to assess daytime sleepiness, particularly in the context of clinical sleep disorders. Its psychometric properties are still unclear, particularly when used to evaluate sleep propensity in patients with obstructive sleep apnoea. Methods: The present study used confirmatory factor analysis (CFA) to investigate a potential single-factor structure of the ESS in a sample of 759 Australian patients with a diagnosis of obstructive sleep apnoea by the treating physicians. Results: CFA results from showed that the original single-factor structure proposed by Johns [Johns MW. Reliability and factor analysis of the Epworth Sleepiness Scale. Sleep 1992;15(4):376–81] did not adequately fit the data. A re-specified single-factor solution provided a good fit for data, and this improved fit was confirmed on a second CFA. Conclusions: The findings suggest that standard scoring of the ESS should be interpreted cautiously for patients with obstructive sleep apnoea.

Impact and interest:

28 citations in Scopus
23 citations in Web of Science®
Search Google Scholar™

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 15529
Item Type: Journal Article
Refereed: Yes
Additional Information: For more information, please refer to the journal's website (see hypertext link) or contact the author.
DOI: 10.1016/j.sleep.2007.08.004
ISSN: 1389-9457
Subjects: Australian and New Zealand Standard Research Classification > PSYCHOLOGY AND COGNITIVE SCIENCES (170000) > PSYCHOLOGY (170100) > Personality Abilities and Assessment (170109)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Copyright Owner: Copyright 2008 Elsevier
Deposited On: 10 Nov 2008 00:00
Last Modified: 29 Feb 2012 13:48

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page