Box. Definition and Measurement of Sleep Problems, NHANES, 2005-2008
Problem	Questionnaire Itema	Possible Responses	Definition
Inadequate sleep	How much sleep do you usually get at night on weekdays or workdays?	Any number of hours with upper limit of 12	<7 h
Severe sleep deprivation	How long does it usually take you to fall asleep?	Any number of minutes with upper limit of 60	≤5 min
Frequent daytime sleepiness	In the past month, how often did you feel excessively or overly sleepy during the day?	Never, rarely (1 time/mo), sometimes (2-4 times/mo), often (5-15 times/mo), almost always (16-30 times/mo)	Often/almost always
Frequent sleeping pill use	In the past month, how often did you take sleeping pills or other medication to help you sleep?
Apnea	In the past 12 months, how often did you snort, gasp, or stop breathing while you were sleeping?	Never, rarely (1-2 nights/wk), occasionally (3-4 nights/wk), frequently (≥5 nights/wk)	Often/almost always or yes and sleep apnea
	Have you ever been told by a doctor or other health professional that you have a sleep disorder?	Yes, no
	What was the sleep disorder?	Sleep apnea, insomnia, restless legs, other
Nocturiab	During the past 30 days, how many times per night did you most typically get up to urinate, from the time you went to bed at night until the time you got up in the morning?	Any number with upper limit of 5	≥2 episodes/ night
Leg symptoms	In the past month, how often did you have leg jerks while trying to sleep?	Never, rarely (1 time/mo), sometimes (2-4 times/mo), often (5-15 times/mo), almost always (16-30 times/mo)	Often/almost always or yes and restless legs
	In the past month, how often did you have leg cramps while trying to sleep?
	Have you ever been told by a doctor or other health professional that you have a sleep disorder?	Yes, no
	What was the sleep disorder?	Sleep apnea, insomnia, restless legs, other

Abbreviation: NHANES, National Health and Nutrition Examination Survey.

^a Adapted by NHANES from the Sleep Heart Study Sleep Habits Questionnaire.

^b From kidney conditions – urology questionnaire of NHANES.