A Single Subjective Question Can Be An Effective Sleepiness Screening Tool

Sarah Nath Zallek, MD, of the Illinois Neurological Institute Sleep Center in Peoria, Ill., sought to determine whether the following single question about sleepiness can measure subjective sleepiness comparably to the Epworth Sleepiness Scale (ESS):

"Please measure your sleepiness on a typical day: (0 = none, 10 is highest)."

The study focused on 303 subjects between 18-78 years of age, who had been diagnosed with a variety of sleep disorders, including obstructive or central sleep apnea, narcolepsy, periodic limb movement disorder, restless legs syndrome, psychophysiological insomnia, inadequate sleep hygiene, and idiopathic hypersomnia. ESS scores ranged from 0-24, while SS scores ranged from 0-10.

According to Dr. Zallek, the finding that the single question used in this study had significant associations with the ESS in all subject groups and was able to distinguish between "subjectively sleepy" and "subjectively not sleepy" groups suggests the SS is a good measure of subjective sleepiness.

"Excessive sleepiness is an important and widespread symptom of insufficient sleep and a variety of sleep disorders," said Dr. Zallek. "It increases the risk of accidents and injuries, and leads to lost work productivity. Recognition of sleepiness is the first step to finding a cause and treating it. Most physicians don't use the existing questionnaires to determine if someone is excessively sleepy. Sleepiness often goes unrecognized."

By using a single question to detect excessive sleepiness, one can quickly determine who might need further evaluation, noted Dr. Zallek.

"This scale can also assess change in an individual's sleepiness over time. This study provides individuals, physicians, and employers a simple, single question to initiate an evaluation of this important symptom," added Dr. Zallek.

On average, most adults need seven to eight hours of nightly sleep to feel alert and well-rested.