Validation of the Arabic version of the epworth sleepiness scale in Oman

Objectives: The Epworth sleepiness scale is a self-administered eight-item questionnaire that was developed as a tool to measure subjective sleepiness in adults. The validity of the Epworth sleepiness scale has been validated and tested in different populations and ethnic groups. However, it has yet to be validated or tested in an Omani or other Arabic speaking population. Thus, the aim of this study is to test the validity and reproducibility of the Epworth sleepiness scale in an Omani population. Methods: Subjects were recruited from the general population and were asked to participate in the study. The study enrolled 97 Omani volunteers and was conducted between May and October 2008. An Arabic version of the original English questionnaire was used. The study was approved by the Research and Ethics committee of the institution. Lin's concordance correlation coefficient along with Bland-Altman plots were used to test the agreement between the Arabic and English versions of the Epworth sleepiness scale. Results: The study included a total of 37 males (38%) and 60 females (62%) with age ranging between 18-75 years. Concordance correlation results revealed a substantial concordance (RhoC) of 0.914, but one that does not approach 1 (95% CI: 0.881, 0.947). This results from both lack of perfect correlation (Pearson's r=0.914) and bias (C_b = 1.000). The Bland and Altman's limits-of-agreement measured at 0.000 (95% CI: -2.684, 2.684), indicating insignificant average departure from agreement between the two versions of the Epworth sleepiness scale. Conclusion: The results indicate agreement between the two versions of ESS (English and the Arabic).