PREVALENCE OF NORMAL EPWORTH SLEEPINESS SCORE IN SLEEP APNEA AND GENDER INFLUENCES

Abstract

PURPOSE: The Epworth Sleepiness Scale (ESS) is a widely used screening tool for evaluation for sleep apnea (OSA) and as a criterion for making decisions about CPAP therapy. A significant proportion of patients with sleep apnea have low ESS scores. The purpose of this study was to evaluate the prevalence of normal ESS score in patients with a diagnosis of OSA METHODS: A retrospective evaluation of all patients referred to our sleep center and who underwent overnight polysomnography (PSG). OSA defined as a AHI of > 15. ESS score <10 considered normal and high if >12. RESULTS: 493 patients were included - 173 were females and 370 males. 54% of patients had a normal ESS. There was no gender difference in prevalence nor any difference in age between high and normal ESS groups. See Table 1. Both RDI and SaO2 nadir were higher in the group with high ESS. CPAP requirements were higher in the High ESS group only in males – in females this difference not seen. Arousal index was higher in males with high ESS group, but interestingly this difference was not seen in females. CONCLUSIONS: More than 50% of patients with OSA have normal ESS scores. Hypoxemia rather than sleep disruption may be a better correlate for daytime sleepiness in OSA. CLINICAL IMPLICATIONS: Use of ESS as a screening tool for OSA may lead to a significant degree of under recognition of this disease. There may be a gender influence on the impact of sleep disruption in modulating daytime sleepiness in OSA.