The Epworth Sleepiness Scale (ESS) is a scale intended to measure daytime

sleep Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain Sensory nervous system, sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with th ...

iness that is measured by use of a very short questionnaire. This can be helpful in diagnosing

sleep disorder A sleep disorder, or somnipathy, is a medical disorder affecting an individual's sleep patterns, sometimes impacting physical, mental, social, and emotional functioning. Polysomnography and actigraphy are tests commonly ordered for diagnosing sle ...

s. It was introduced in 1991 by Dr Murray Johns of Epworth Hospital in

Melbourne, Australia Melbourne ( , ; Boonwurrung/ or ) is the capital and most populous city of the Australian state of Victoria, and the second most-populous city in Australia, after Sydney. The city's name generally refers to a metropolitan area also known ...

The questionnaire

The questionnaire asks the subject to rate their probability of falling asleep on a scale of increasing probability from 0 to 3 for eight different situations that most people engage in during their daily lives, though not necessarily every day. The scores for the eight questions are added together to obtain a single number. A number in the 0–9 range is considered to be normal while a number in the 10–24 range indicates that expert medical advice should be sought. For instance, scores of 11–15 are shown to indicate the possibility of mild to moderate

sleep apnea Sleep apnea (sleep apnoea or sleep apnœa in British English) is a sleep-related breathing disorder in which repetitive Apnea, pauses in breathing, periods of shallow breathing, or collapse of the upper airway during sleep results in poor vent ...

, where a score of 16 and above indicates the possibility of severe sleep apnea or

narcolepsy Narcolepsy is a chronic neurological disorder that impairs the ability to regulate sleep–wake cycles, and specifically impacts REM (rapid eye movement) sleep. The symptoms of narcolepsy include excessive daytime sleepiness (EDS), sleep-r ...

. Certain questions in the scale were shown to be better predictors of specific sleep disorders, though further tests may be required to provide an accurate diagnosis. The questionnaire was originally created with the intent to preserve the exact wording of the questionnaire to provide a standardized test and preserve its validity. Johns, the author of the ESS, recommends that the administrator of the questionnaire does not discuss the results of the test with the subject until it is completed, as it could affect the subject's responses on the questionnaire. An interactive calculator is available that utilizes the 1997 version of the ESS. It automatically provides the score based on the responses to the ESS questions
ESS interactive calculator

Calibration

The Epworth Sleepiness Scale has been validated primarily in

obstructive sleep apnea Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial airway obstruction, obstruction of the respiratory tract#Upper respiratory tract, upper airway lea ...

, though it has also shown success in detecting

and idiopathic hypersomnia. It is used to measure excessive daytime sleepiness and is repeated after the administration of treatment (e.g., CPAP) to document improvement of symptoms. In

, the Epworth Sleepiness Scale has both a high specificity (100%) and sensitivity (93.5%). The Epworth Sleepiness Scale has been used to compare the sensitivity and specificity of other similar measurements of sleep quality. The Pittsburgh Sleep Quality Index is a related scoring tool of sleep quality. Both scores are internally highly reproducible. The test has limitations that can affect the test's accuracy. The test is based on subjectivity and therefore may not be accurate when factors such as: the test takers opinions on their sleep, how others view their sleepiness, education level, and others are considered. The test can be biased as pre-emptive discussion of results can have an effect on the responses while the test is being taken.

References

External links

Epworth Sleepiness Scale (official website)

1997 version of the questionnaire
described on the above site as the "standard version that can be used by most adults."

uses the 1997 version of the ESS questionnaire and published with permission from Lauren Clowney. {{Neuropsychology tests Sleep disorders Mental disorders screening and assessment tools Neuropsychological tests Medical tests