Subjective assessment of daytime sleepiness in patients with obstructive sleep apnea and snoring
A.Yu. Melnikov, S.O. Kravchenko

Research and Clinical Center of Otorhinolaryngology, Moscow

Objective. To compare subjective methods of daytime sleepiness assessment and to identify correlation between daytime sleepiness, obstructive sleep apnea (OSA) and its severity by means of polysomnography (PSG). 
Material and methods. The study included 200 patients (152 men and 48 female), mean age 44,6±0,83. PSG revealed severe OSAS in 103 patients, moderate - in 42, mild - in 50, no OSAS - in 5 patients. Epworth Sleepiness Scale (ESS) scores were evaluated as well as two single questions about daytime sleepiness and imperative sleep onset. Correlation between ESS score, answers to single questions, OSAS severity (by apnea/hypopnea index - AHI) and chronic nocturnal hypoxemia severity (by average oxygen saturation) was determined.
Results. Correlation between three subjective methods of daytime sleepiness severity assessment was weak. AHI association with ESS score was very weak (r = 0,26, p <0,01). ESS score statistically significant differed between severe and mild OSAS groups, but there was no difference between mild and moderate as well as moderate and severe OSAS groups. Correlation between average saturation and ESS score was revealed (r =-0,31, p <0,01). 
Conclusions. No significant correlation between patient's assessment of daytime sleepiness and ESS score was revealed. ESS score and OSAS severity correlated weakly. Results demonstrate the necessity to perform accessible and reliable methods for objective daytime sleepiness assessment in patients with snoring and sleep breathing disorders. Primary snoring prevalence in studied population was insignificant, as well as snoring intensity in patients without OSAS according to PSG.

Key words: sleep apnea, daytime sleepiness, Epworth Sleepiness Scale (ESS)

For citation: Melnikov A.Yu., Kravchenko S.O. Subjective assessment of daytime sleepiness in patients with obstructive sleep apnea and snoring // RMJ. 2016. № 13. P. 856– 859.