A New Method for Measuring Daytime Sleepiness: The Epworth Sleepiness Scale

TLDR

The Epworth Sleepiness Scale is a simple, self‑administered questionnaire that measures general daytime sleepiness. The study develops and describes the use of the Epworth Sleepiness Scale. The ESS was administered to 180 adults—30 controls and 150 patients with various sleep disorders—who rated their likelihood of dozing in eight common daily situations. ESS scores differentiated normal subjects from patients with obstructive sleep apnea, narcolepsy, and idiopathic hypersomnia, correlated with sleep latency on the multiple sleep latency test and overnight polysomnography, and, in OSA patients, with respiratory disturbance index and minimum SaO₂, but did not differ in simple snorers.

Abstract

The development and use of a new scale, the Epworth sleepiness scale (ESS), is described. This is a simple, self-administered questionnaire which is shown to provide a measurement of the subject's general level of daytime sleepiness. One hundred and eighty adults answered the ESS, including 30 normal men and women as controls and 150 patients with a range of sleep disorders. They rated the chances that they would doze off or fall asleep when in eight different situations commonly encountered in daily life. Total ESS scores significantly distinguished normal subjects from patients in various diagnostic groups including obstructive sleep apnea syndrome, narcolepsy and idiopathic hypersomnia. ESS scores were significantly correlated with sleep latency measured during the multiple sleep latency test and during overnight polysomnography. In patients with obstructive sleep apnea syndrome ESS scores were significantly correlated with the respiratory disturbance index and the minimum SaO2 recorded overnight. ESS scores of patients who simply snored did not differ from controls.