Table 2.

Sleep disturbances at baseline among women in SWAN included in the primary cohort

	No sleep medication n=447	Sleep medication user n=238	SMD
Trouble initiating sleep, mean (95% CI)*	2.6 (2.5 to 2.7)	2.7 (2.5 to 2.9)	0.08
Waking frequently, mean (95% CI)*	3.7 (3.6 to 3.9)	3.8 (3.6 to 3.9)	0.03
Early morning awakening, mean (95% CI)*	2.7 (2.6 to 2.8)	2.8 (2.6 to 3.0)	0.07
Trouble initiating sleep, at least three nights per week, n (%)	137 (30.7)	82 (34.5)	0.07
Waking frequently, at least three nights per week, n (%)	291 (65.1)	158 (66.4)	0.008
Early morning awakening, at least three nights per week, n (%)	135 (30.2)	81 (34.0)	0.07
Any disturbance, at least three nights per week, n (%)	322 (72.0)	183 (76.9)	0.08

*Mean calculated based on 5-point Likert scale, where 1=no difficulties on any nights, 2=difficulties on less than one night per week, 3=one to two nights per week, 4=three to four nights per week and 5=five to seven nights per week.

SMD, standardised mean difference; SWAN, Study of Women’s Health Across the Nation.