Table 3.

Summary of Hierarchical Regression Analysis examining the mediation of country and sleep duration by school start time, parent-set bedtimes and extra-curricular load, after controlling for age and sex

Variable	B	SE B	Beta	p
Step 2
Sex	−11.91	4.81	−.09	.01
Age	−8.83	2.21	−.15	<.001
Parent-set bedtime	−23.64	7.07	−.13	.001
School start time	28.54	5.09	.22	<.001
Extra-curricular load	−.85	.29	−.11	.004
Step 3
Sex	−8.37	4.68	−.07	ns
Age	−6.96	2.15	−.12	.001
Parent-set bedtime	−19.50	6.87	−.10	.005
School start time	−13.30	8.00	−.10	ns
Extra-curricular load	−.53	.29	−.07	ns
Country	53.39	8.05	.42	<.001