Table 2.

Sleep characteristics at the first and second assessment of the full sample when all women were pre- or early peri-menopausal and for each menopause transition group based on menopausal status at the second sleep assessment

	Time	N	Full sample	Pre/early peri-menopause (N = 38)	Pre/early peri-menopause to late peri-menopause (N = 31)	Pre/early peri-menopause to postmenopause (N = 90)	p-value for group differences at first assessment
Sleep duration, mean hours (SD)	1	159	6.39 (0.89)	6.67 (0.84)	6.41 (0.76)	6.26 (0.92)	0.06
	2	159	6.42 (1.02)	6.50 (1.20)	6.62 (1.15)	6.32 (0.88)
Wake after sleep onset, mean minutes (SD)	1	159	47.41 (30.22)	45.92 (26.53)	46.25 (27.03)	48.43 (32.86)	0.99
	2	159	60.27 (43.93)	49.66 (30.85)	58.25 (38.72)	65.44 (49.48)
Log NREM Delta EEG power, mean (SD)	1	136	2.19 (0.19)	2.18 (0.18)	2.22 (0.24)	2.19 (0.17)	0.68
	2	136	2.22 (0.22)	2.20 (0.20)	2.21 (0.25)	2.23 (0.22)
Log NREM Beta EEG power, mean (SD)	1	136	0.51 (0.20)	0.46 (0.17)	0.58 (0.28)	0.51 (0.17)	0.07
	2	136	0.57 (0.20)	0.50 (0.16)	0.55 (0.23)	0.61 (0.21)
Log REM Delta EEG power, mean (SD)	1	133	1.58 (0.15)	1.55 (0.13)	1.61 (0.16)	1.58 (0.16)	0.26
	2	133	1.61 (0.20)	1.58 (0.20)	1.59 (0.21)	1.62 (0.19)
Log REM Beta EEG power, mean (SD)	1	135	0.55 (0.19)	0.54 (0.21)	0.57 (0.17)	0.55 (0.19)	0.83
	2	135	0.63 (0.20)	0.63 (0.24)	0.61 (0.21)	0.64 (0.18)