Table 5.

Categorical moderators of meta-analytic associations of age and actigraphy-assessed sleep characteristics

	Sleep duration		Sleep efficiency		Bedtime, ages 6–21
Moderators	k	ES [95% CI]	k	ES [95% CI]	k	ES [95% CI]
Continent		R 2 = 10%, p < .001		R 2 = 16%, p < .001		R 2 = 0%, p = .20
North America	53	−0.06 [−0.10, −0.02]	37	−0.006 [−0.06, 0.05]	8	Insufficient N
Europe	19	−0.13 [−0.22, −0.03]	9	Insufficient N	5	Insufficient N
Asia	7	Insufficient N	5	Insufficient N	0	Insufficient N
Exclusion criteria
Mental health		R 2 = 4%, p = .05		R 2 = 0%, p = .57		R 2 = 15%, p = .008
Excluded	34	−0.20 [−0.30, −0.09]*	23	−0.08 [−0.22, 0.07]	7	Insufficient N
Included	55	−0.08 [−0.12, −0.03]	35	−0.04 [−0.08, 0.008]	12	0.22 [0.05, 0.38]
Medical		R 2 = 2%, p = .03		R 2 = 0%, p = .12		R 2 = 0%, p = .60
Excluded	41	−0.18 [−0.26, −0.09]*	33	−0.10 [−0.19, −0.005]*	8	Insufficient N
Included	48	−0.07 [−0.12, −0.02]	25	−0.01 [−0.07, 0.04]	11	0.32 [0.19, 0.44]*
Sleep disorders		R 2 = 2%, p = .09		R 2 = 0%, p = .61		R 2 = 0%, p = .23
Excluded	26	−0.19 [−0.28, −0.09]*	18	−0.03 [−0.13, 0.07]	8	Insufficient N
Included	63	−0.09 [−0.15, −0.04]*	40	−0.06 [−0.12, 0.001]	11	0.28 [0.06, 0.48]
Actigraphy device		R 2 = 0%, p = .34		R 2 = 0%, p = .39		R 2 = 0%, p = .91
Philips	37	−0.11 [−0.17, −0.04]	18	−0.12 [−0.22, −0.01]*	10	0.38 [0.22, 0.52]*
AMI	29	−0.17 [−0.27, −0.07]	25	−0.04 [−0.10, 0.03]	5	Insufficient N
ActiGraph	8	Insufficient N	3	Insufficient N	1	Insufficient N
Other	15	−0.05 [−0.15, 0.06]	12	−0.01 [−0.17, 0.15]	3	Insufficient N

k, number of effect sizes; ES, effect size, 95% CI, 95% confidence interval; R², variance explained in the meta-analytic effect size by the categorical moderator; AMI, Ambulatory Monitoring, Inc.

*p < .001, which is the Bonferroni-corrected threshold for significance.