The DOI matches its Crossref record.
Reliability and Factor Analysis of the Epworth Sleepiness Scale
Abstract
The Epworth Sleepiness Scale (ESS) is a self-administered eight-item questionnaire that has been proposed as a simple method for measuring daytime sleepiness in adults. This investigation was concerned with the reliability and internal consistency of the ESS. When 87 healthy medical students were tested and retested 5 months later, their paired ESS scores did not change significantly and were highly correlated (r = 0.82). By contrast, ESS scores that were initially high in 54 patients suffering from obstructive sleep apnea syndrome returned to more normal levels, as expected, after 3-9 months' treatment with nasal continuous positive airway pressure. The questionnaire had a high level of internal consistency as measured by Cronbach's alpha (0.88). Factor analysis of item scores showed that the ESS had only one factor for 104 medical students and for 150 patients with various sleep disorders. The ESS is a simple and reliable method for measuring persistent daytime sleepiness in adults.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cited by
Shamseer, L., Moher, D., Clarke, M., Ghersi, D., Liberati, A., Petticrew, M., Shekelle, P., Stewart, L. A., & the PRISMA-P Group (2015) · BMJ · doi:10.1136/bmj.g7647 · Cited by 13,120
The Cardiovascular Health Study: design and rationale.
Fried, L. P., Borhani, N. O., Enright, P., Furberg, C. D., Gardin, J. M., Kronmal, R. A., Kuller, L. H., Manolio, T. A., Mittelmark, M. B., Newman, A., et al. (1991) · Annals of Epidemiology · doi:10.1016/1047-2797(91)90005-w · Cited by 3,652
Sleep Patterns and Predictors of Disturbed Sleep in a Large Population of College Students
Lund, H. G., Reider, B. D., Whiting, A. B., & Prichard, J. R. (2010) · Journal of Adolescent Health · doi:10.1016/j.jadohealth.2009.06.016 · Cited by 1,907
Yu, L., Buysse, D. J., Germain, A., Moul, D. E., Stover, A., Dodds, N. E., Johnston, K. L., & Pilkonis, P. A. (2012) · Behavioral Sleep Medicine · doi:10.1080/15402002.2012.636266 · Cited by 1,241
“…the Pittsburgh Sleep Quality Index (PSQI; Buysse, Reynolds, Monk, Berman, & Kupfer, 1989) is the most widely used scale for sleep disturbance, and the Epworth Sleepiness Scale (ESS; Johns, 1991, 1992) is the most widely used measure of daytime sleepiness, each with over 500 literature citations.”
MethodAssociation of resident fatigue and distress with perceived medical errors
West, C. P. (2009) · JAMA · doi:10.1001/jama.2009.1389 · Cited by 999
Metadata
- Authors
- Johns, M. W.
- Venue
- Sleep
- Publisher
- Oxford University Press (OUP)
- Published
- 1992-07
- Volume
- 15
- Issue
- 4
- Pages
- 376-381
- ISSN
- 0161-8105 (ISSN-L)
- 1550-9109
- OpenAlex
- W2303635956
- Cited by
- 2,122
- References
- 0
- FWCI
- 5.96
- Type
- journal article
- Language
- en
- Open access
- closed
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Reliability and Factor Analysis of the Epworth Sleepiness Scale. https://app.cochat.ai/papers/10.1093/sleep/15.4.376
- The paper
- Johns, M. W. (1992). Reliability and Factor Analysis of the Epworth Sleepiness Scale. Sleep. https://doi.org/10.1093/sleep/15.4.376
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
