The Serbian version of the Epworth Sleepiness Scale

The Epworth Sleepiness Scale (ESS) is extensively used for evaluating daytime sleepiness in patients with sleep apnea-hypopnea syndrome (SAHS). The aim of this study was to translate and validate the ESS in the Serbian language. The Serbian version of the ESS (ESSs) was administered to 112 patients with symptoms of sleep disorder breathing referred to Sleep Center of the Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica, Serbia and 111 healthy controls. Test-retest reliability was tested in 19 healthy subjects. Patients referred to the Sleep center had significantly higher ESS scores compared to controls (9 vs. 4, p < 0.001). The difference was also present for each item separately, excluding item 5. The ESSs scores were significantly higher in patients with severe (median, 13.5; interquartile range (IQR), 10.3-17.8) compared to moderate (median, 9; IQR, 7.3-9.5; p = 0.005) and mild SAHS (median, 8; IQR, 5.5-9.7; p < 0.001). Item analysis demonstrated good internal consistency of the scale (Cronbach's alpha 0.88 in patients and 0.72 in healthy controls). Test-retest Spearman's correlation coefficient was 0.68 (p = 0.001). The Serbian version of the ESS demonstrated good internal consistency and test-retest reliability. The ESSs could be used for both clinical practice and research in Serbian population.