BACKGROUND: The Epworth Sleepiness Scale (ESS) is a largely wide used scale for sleepiness assessment. Measurement properties are studied in a sample of Portuguese adults, using different statistical procedures. METHODS: The sample consisted of 222 Portuguese adults (97 men and 125 women) with a mean age of 42 years old (SD = 12.5), 46 of which had obstructive sleep apnea (OSA) confirmed by polysomnography. The participants were assessed with the ESS, which was tested through a quantitative analysis based on the classical measurement theory (CMT) or the Rasch model (RM) conventions. RESULTS: A principal component factor analysis was performed according to the CMT, revealing a single factor explaining 39.92% of the total variance of the scale. Internal consistency measured by Cronbach's α coefficient was of .77. The mean of inter-item correlation was of .31 (.05 < r > .47), whereas the item-total correlations were considered good (.46 < r > .73). The ESS total score for OSA patients was significantly higher than healthy participants (p < .05). Overall data from the RM analysis was consistent with the guidelines of Linacre and essential unidimensionality was empirically corroborated (61% the percentage of variance explained by the Rasch analysis). Model fit is adequate and the reliability coefficients for both items (.99) and subjects (.78) were considered good. The Cronbach's α coefficient was also satisfactory (.78). CONCLUSIONS: The ESS showed an adequate structural, internal, and criterion validity, both in the CMT and the RM, suggesting this as a useful and effective measure for assessing sleepiness in Portuguese adults.
BACKGROUND: The Epworth Sleepiness Scale (ESS) is a largely wide used scale for sleepiness assessment. Measurement properties are studied in a sample of Portuguese adults, using different statistical procedures. METHODS: The sample consisted of 222 Portuguese adults (97 men and 125 women) with a mean age of 42 years old (SD = 12.5), 46 of which had obstructive sleep apnea (OSA) confirmed by polysomnography. The participants were assessed with the ESS, which was tested through a quantitative analysis based on the classical measurement theory (CMT) or the Rasch model (RM) conventions. RESULTS: A principal component factor analysis was performed according to the CMT, revealing a single factor explaining 39.92% of the total variance of the scale. Internal consistency measured by Cronbach's α coefficient was of .77. The mean of inter-item correlation was of .31 (.05 < r > .47), whereas the item-total correlations were considered good (.46 < r > .73). The ESS total score for OSA patients was significantly higher than healthy participants (p < .05). Overall data from the RM analysis was consistent with the guidelines of Linacre and essential unidimensionality was empirically corroborated (61% the percentage of variance explained by the Rasch analysis). Model fit is adequate and the reliability coefficients for both items (.99) and subjects (.78) were considered good. The Cronbach's α coefficient was also satisfactory (.78). CONCLUSIONS: The ESS showed an adequate structural, internal, and criterion validity, both in the CMT and the RM, suggesting this as a useful and effective measure for assessing sleepiness in Portuguese adults.
Authors: Lidwine B Mokkink; Caroline B Terwee; Donald L Patrick; Jordi Alonso; Paul W Stratford; Dirk L Knol; Lex M Bouter; Henrica C W de Vet Journal: Qual Life Res Date: 2010-02-19 Impact factor: 4.147
Authors: Marco Fabbri; Alessia Beracci; Monica Martoni; Debora Meneo; Lorenzo Tonetti; Vincenzo Natale Journal: Int J Environ Res Public Health Date: 2021-01-26 Impact factor: 3.390
Authors: Md Dilshad Manzar; Mohammed Salahuddin; Majed Alamri; Abdulrhman Albougami; Mohammad Yunus Ali Khan; Dejen Nureye; D Warren Spence; Seithikurippu R Pandi-Perumal Journal: Health Qual Life Outcomes Date: 2019-02-07 Impact factor: 3.186