Table 1. Mean differences between the three sleep measures for average weekday, weekend and combined sleep duration in 225 adolescents.

Measure	Measure	Mean difference	p value	95% CI
Average weekday sleep duration (minutes)
Self-report	Sleep diary	13.6	0.017	1.8, 25.4
Self-report	Actigraphy	95.5	<0.001	83.7, 107.3
Actigraphy	Sleep diary	-81.9	<0.001	-93.7, -70.1
Average weekend sleep duration (minutes)
Self-report	Sleep diary	72.0	<0.001	55.4, 88.5
Self-report	Actigraphy	156.7	<0.001	140.2, 173.3
Actigraphy	Sleep diary	-84.8	<0.001	-101.3, -68.2
Average combined sleep duration (minutes)
Self-report	Sleep diary	57.6	<0.001	44.8, 70.4
Self-report	Actigraphy	111.8	<0.001	99.0, 124.6
Actigraphy	Sleep diary	-54.2	<0.001	-67.0, -41.3

CI = confidence intervals