Epworth sleepiness scale: A meta-analytic study on the internal consistency
Maria Teresa Gonçalves, Simone Malafaia, José Moutinho dos Santos, Thomas Roth, Daniel Ruivo Marques
Sleep Medicine
Abstract
OBJECTIVE/BACKGROUND: The Epworth Sleepiness Scale (ESS) is one of the most used self-reported instruments to assess sleepiness. Thus, several adaptations into different Languages have been performed worldwide over the years. The scale has produced disparate psychometric properties when applied in different settings. In the current study, our aim was to perform a Reliability Generalization meta-analysis of the Cronbach᾽s alphas of all published studies on ESS, specifically with a psychometric focus. PATIENTS/METHODS: Three reference databases (Scopus, PubMed and Web of Science) were searched since 1991 to October 2022 and all the records on psychometric or validation studies that reported Cronbach's alphas, from clinical and nonclinical groups, were included. In total, data from 46 publica