Table 2.

Symptoms and Risk Factors Comparing Self-Reported Incident Cases of Obstructive Sleep Apnea Versus Noncases, Nurses’ Health Study (2002–2012) and Nurses’ Health Study II (1995–2013), United States

OSA-Related Factor	Self-Reported OSAa
	Nurses’ Health Study				Nurses’ Health Study II
	Yes (n = 1,712)		No (n = 48,761)		Yes (n = 2,560)		No (n = 51,267)
	Mean (SD)	%	Mean (SD)	%	Mean (SD)	%	Mean (SD)	%
Habitual snoringb		65.3		26.3		64.8		24.0
Excessive daytime sleepinessc		10.1		3.0		19.0		9.2
Witnessed apneasd						63.6		3.3
Body mass indexe	30.7 (6.3)			26.6 (5.1)	32.3 (7.4)		27.0 (6.0)
Waist circumference, cm	95.2 (15.0)			86.4 (13.2)	96.4 (16.5)		84.3 (13.9)

Abbreviations: OSA, obstructive sleep apnea; SD, standard deviation.

^aP < 0.0001 for all comparisons by OSA status in each cohort.

^b Defined as snoring every night or most nights.

^c Reporting sleepiness for ≥4 days/week.

^d Assessed only in Nurses’ Health Study II.

^e Weight (kg)/height (m)².