The Epworth sleepiness scale is a questionnaire that is routinely used to assess the degree of an individual’s sleepiness. It is a subjective measure completed by patients, but it can be helpful in quantifying one's sleepiness over time. The scale is completed by an individual and given to his or her doctor. It is often used as a screening test for sleepiness or to monitor response to a treatment.
The scale measures an individual’s likelihood of falling asleep in routine life situations. The situations described on the questionnaire are the following:
- Sitting and reading
- Watching television
- Sitting inactively in a public place
- Riding as a passenger in a car for one hour without a break
- Lying down to rest in the afternoon when circumstances permit
- Sitting and talking with someone
- Sitting quietly after lunch without alcohol
- Sitting in a car as the driver, while stopped for a few minutes in traffic
For each situation, a score is assigned that indicates the likelihood a person would fall asleep. The scores range from zero to three:
- 0 = would never doze
- 1 = slight chance of dozing
- 2 = moderate chance of dozing
- 3 = high chance of dozing
The total score can range from zero to 24, and higher scores are correlated with increased sleepiness. This correlation has been established with a large study comparing the results of the Epworth scale to the ability to fall asleep during a Multiple Sleep Latency Test (MSLT).
The average score among healthy adults is six. In general, scores higher than eight indicate excessive sleepiness. Higher scores may occur in patients with narcolepsy, idiopathic hypersomnia, or sleep apnea.
Though the Epworth sleepiness scale is easy to administer and adds some basic information about sleepiness, it is admittedly a measure with a somewhat limited purpose.
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Punjabi, N et al. "Predictors of objective sleep tendency in the general population." Sleep. 2003; 25:678.