Table 3.

Binomial logistic regressions (with further adjustments for covariates)

	Low: <1 hours		High: 3 to <5 hours		Very high: 5+ hours
	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)	P value
Late sleep onset (school days)	0.61 (0.51 to 0.73)	<0.001	1.23 (1.02 to 1.49)	<0.05	2.14 (1.83 to 2.5)	<0.001
Late sleep onset (free days)	0.57 (0.49 to 0.68)	<0.001	1.32 (1.09 to 1.6)	<0.01	2.41 (2.08 to 2.79)	<0.001
Late wake time (school days)	1.04 (0.71 to 1.5)	ns	1.56 (1.02 to 2.4)	<0.05	1.97 (1.32 to 2.93)	<0.01
Late wake time (free days)	0.79 (0.67 to 0.93)	<0.01	1.12 (0.92 to 1.35)	ns	1.57 (1.32 to 1.87)	<0.001
Sleep onset latency >30 min	0.9 (0.78 to 1.04)	ns	1.11 (0.92 to 1.34)	ns	1.12 (0.96 to 1.32)	ns
Frequent nighttime awakenings	1.04 (0.88 to 1.24)	ns	1.08 (0.87 to 1.35)	ns	1.36 (1.1 to 1.66)	<0.01

See table 1 for criteria and prevalence of each sleep outcome. Reference category is average (1 to <3 hours). ORs are adjusted to control for: exact age, sex, ethnic minority status, family income, number of siblings in household, the presence of both parents in household, parent’s age, Strengths and Difficulties score, Mood and Feelings score, self-esteem, general health, social support and physical activity.

ns, not significant.