Table 3.

Item-level sleep practices descriptive statistics and bivariate associations with sleep disturbance and sleep-related impairment

	Descriptive statistics			Sleep disturbance (B)			Sleep related impairment (B)
	All Children (n = 307)	Ages 8–12 (n=171)	Ages 13–17 (n=136)	All children	Ages 8–12	Ages 13–17	All children	Ages 8–12	Ages 13–17
Weekday bedtime (time), M(SD)	21:31 (1:01)	21:06 (0:50)	22:02 (1:00)
Recommendeda	61%	59%	63%	ref	ref	ref	ref	ref	ref
Latea	29%	33%	23%	0.48	1.39	0.20	2.57	2.20	3.92
Very latea	10%	7%	14%	4.70+	6.35	2.71	4.91*	4.30	4.76
Weekday sleep opportunity (h), M(SD)	9.08 (1.20)	9.62 (0.98)	8.43 (1.13)
Recommendedb	62%	67%	57%	ref	ref	ref	ref	ref	ref
Insufficientb	26%	24%	28%	0.83	1.49	−0.31	2.24	1.33	2.42
Very insufficientb	12%	9%	15%	3.77	2.40	3.19	5.46*	5.79+	4.36
Δ weekday vs. weekend sleep opportunity (h), M(SD)	1.12 (1.65)	0.53 (1.38)	1.87 (1.63)
Small Δ (< 1 hour)	58%	72%	41%	ref	ref	ref	ref	ref	ref
Moderate Δ (1–2 hours)	8%	9%	6%	−1.18	−1.94	1.56	1.33	−0.04	3.45
Large Δ (> 2 hours)	34%	19%	53%	2.01	−0.08	1.68	4.97***	5.46*	3.43
Followed a bedtime routine, M(SD)	1.10 (0.81)	0.94 (0.81)	1.30 (0.77)
Always (0)	28%	36%	19%	ref	ref	ref	ref	ref	ref
Almost always (1)	33%	34%	33%	3.75****	3.11**	4.41**	3.88****	3.29**	3.80**
Never, almost never, sometimes (2)	39%	30%	49%	6.37****	5.99***	6.43****	7.04****	6.40****	6.52***
Tried to fall asleep at about the same time every night, M(SD)	1.17 (0.73)	1.11 (0.75)	1.25 (0.71)
Always (0)	20%	23%	16%	ref	ref	ref	ref	ref	ref
Almost always (1)	43%	43%	44%	3.64***	3.97***	2.91*	3.66***	3.39**	3.74*
Never, almost never, sometimes (2)	37%	34%	40%	8.27***	7.49***	8.53***	7.50****	6.99****	7.35***
Woke up at about the same time every morning, M(SD)	1.06 (0.71)	0.99 (0.71)	1.15 (0.69)
Always (0)	22%	26%	18%	ref	ref	ref	ref	ref	ref
Almost always (1)	50%	49%	50%	3.58***	3.60***	2.95*	4.01***	3.89***	3.15*
Never, almost never, sometimes (2)	28%	25%	32%	7.99***	9.36***	5.82***	6.81***	8.36***	4.00**
Technology use before bed, M(SD)	1.38 (0.67)	1.22 (0.70)	1.56 (0.59)
Never (0)	11%	15%	5%	ref	ref	ref	ref	ref	ref
Almost never, sometimes (1)	41%	47%	34%	4.76***	5.63***	1.58	5.93***	5.47***	6.23**
Almost always, always (2)	48%	38%	61%	7.63****	6.74***	6.13*	9.95***	8.69***	10.22***
Problems sleeping because too noisy, M(SD)	0.25 (0.47)	0.25 (0.48)	0.25 (0.45)
Never (0)	77%	78%	76%	ref	ref	ref	ref	ref	ref
Almost never, sometimes (1)	21%	20%	23%	6.85***	6.44***	7.14***	6.94***	6.52***	7.17***
Almost always, always (2)	2%	2%	1%	11.01***	11.38***	12.11*	9.48***	8.92**	13.34**
Problems sleeping because too hot or too cold, M(SD)	0.44 (0.57)	0.41 (0.55)	0.47 (0.58)
Never (0)	60%	62%	58%	ref	ref	ref	ref	ref	ref
Almost never, sometimes (1)	37%	35%	38%	7.71***	8.96***	7.22***	6.95***	7.47***	6.08***
Almost always, always (2)	4%	3%	5%	16.29***	14.16***	17.33***	11.39***	10.33***	11.81***
Problems sleeping because too much light, M(SD)	0.24 (0.45)	0.23 (0.45)	0.25 (0.45)
Never (0)	77%	79%	76%	ref	ref	ref	ref	ref	ref
Almost never, sometimes (1)	21%	20%	23%	6.99***	6.65***	7.16***	6.76***	5.98***	7.09***
Almost always, always (2)	1%	1%	1%	7.44*	7.02*	8.07*	5.13*	9.13*	1.89
Needed someone to fall asleep, M(SD)
Never (0)	77%	69%	87%	ref	ref	ref	ref	ref	ref
Almost never (1)	9%	10%	7%	2.77	2.59	4.35	2.33	1.53	4.44*
Sometimes, almost always, always (2)	14%	21%	6%	5.40****	5.40***	10.83***	4.09***	4.58***	8.14***

Notes:

^aWeekday bedtimes: recommended = at/before 21:00 for ages 8–12, at/before 22:00 for ages 13–17; late = after 21:00 and at/before 22:00 for ages 8–12, after 22:00 and at/before 23:00 for ages 13–17, very late = after 22:00 for ages 8–12; after 23:00 for ages 13–17.

^bWeekday sleep opportunity: recommended = ≥ 9.50 for ages 8–12, ≥ 8.50 for ages 13–17; insufficient = 8.50–9.50 for ages 8–12, 7.50–8.50 for ages 13–17; very insufficient = < 8.50 for ages 8–12, < 7.50 for ages 13–17.

p values using Sidak correction for multiple comparisons:

⁺p < 0.10;

^*p < 0.05;

^**p < 0.01;

^***p < 0.001;

^****p < 0.0001.

ref = reference category