The deficiencies of epworth sleepiness scale in the evaluation of excessive daytime sleepiness in obstructive sleep apnea and related factors

Background Epworth Sleepiness Scale(ESS) is widely used in the assessment of excessive daytime sleepiness (EDS) despite certain deficiencies. It was aimed to evaluate the factors associated with low ESS scores in subjects investigated for OSA. MethodsIn this cross sectional study, we recorded the ESS and Pittsburg sleep quality index (PSQI) scores of patients undergoing polysomnography in our sleep center between November 2022-January 2023. Additional questions regarding literacy, vehicle use, driver licence and travelling habits were asked. Sleep indices of patients with AHI >= 5 were recorded following PSG. Results 96 patients with mean age 51 +/- 12, 68% male, median AHI 34.6 (7-105), ESS 7 (0-22), PSQI 9 (2-15) were included. Among moderate-severe OSA patients without EDS; 10% were illiterate, 67% performed reading only from cellular phone, 88% did not attend the social settings, 53% did not travel frequently and 40% did not use any vehicle. The listed factors were also associated with low ESS (p < 0.001). The sleep indices and PSQI scores of patient groups with and without EDS were similar. There was a correlation between ESS and total PSQI score (beta = 0.31, p = 0.002) and subjective sleep quality (beta = 0.21, p = 0.04), sleep disturbances (beta = 0.29, p = 0.004) and daytime dysfunction (beta = 0.49, p < 0.001) domains. Conclusion ESS may be inadequate in the assessment of the demographical features and daily habits of patients from different sociocultural settings. Clinicians should be aware that the patients may have severe OSA and poor sleep quality despite low ESS scores and should evaluate each patient individually.