Table 2.

Association between log transformed cortisol (pg/mg) and sleep latency, sleep duration, sleep efficiency and physical activity before and after adjusting for sex, age and BMI z - scores

	Crude				Adjusted
	R2	Β	95% CI	p value	R2	β	95% CI	p value
Sleep latency (min)	0.038	0.015	(−0.00, 0.035)	0.13	0.188	0.0084	(−0.011, 0.028)	0.40
Sleep duration (hours)	< 0.001	−0.0016	(−0.34, 0.34)	0.99	0.179	0.055	(−0.27, 0.38)	0.74
Sleep efficiency (%)a	0.030	−3.1	(−7.7, 1.5)	0.18	0.179	−0.60	(−5.3, 4.1)	0.80
Physical activity (100 CPM)b	0.033	0.014	(−0.008, 0.036)	0.22	0.178	0.013	(−0.009, 0.035)	0.22

^a: percentage of minutes scored as sleep during the down time interval; ^b Counts per minute