. 2023 May 1;19(5):925–934. doi: 10.5664/jcsm.10484

Table 3.

Intraindividual variability and social jetlag measured with actigraphy based on 1 week of recording in typically developing and gifted children.

	TDC (n = 36)^a	Gifted (n = 55)^a	t	df	P	Cohen’s d
	mean ± SD	mean ± SD	t	df	P	Cohen’s d
SOL (min)
School nights	12 ± 10	14 ± 11	−1.062	84	.291	0.00
Weekends^a	9 ± 7	16 ± 14	−2.353	63	.022	0.63
Total	14 ± 8	16 ± 10	−1.010	84	.315	0.27
WASO (min)
School nights	6 ± 3	8 ± 4	−2.156	88	.034	0.47
Weekends^a	7 ± 4	9 ± 7	−1.212	88	.229	0.28
Total	7 ± 3	9 ± 5	−2.565	88	.012	0.59
TST (min)
School nights	24 ± 11	28 ± 12	−1.860	88	.066	0.41
Weekends^a	42 ± 36	37 ± 27	0.751	88	.454	0.16
Total	34 ± 14	34 ± 12	−0.082	88	.935	0.02
SE (%)
School nights	1.04 ± 0.6	1.28 ± 0.7	−1.729	88	.087	0.38
Weekends^a	1.23 ± 0.8	1.29 ± 1.1	−0.316	88	.753	0.07
Total	1.16 ± 0.5	1.42 ± 0.7	−1.967	88	.052	0.44
Bedtime (min)
School nights	22 ± 12	20 ± 11	0.906	89	.367	0.21
Weekends^a	33 ± 29	29 ± 27	0.682	89	.497	0.15
Total	38 ± 17	31 ± 13	2.209	89	.030	0.48
Wake-up time (min)
School nights	16 ± 10	24 ± 14	−2.815	89	.006	0.64
Weekends^a	34 ± 28	23 ± 18	2.279	89	.025	0.46
Total	35 ± 20	30 ± 16	1.271	89	.207	0.27
MP (min)
School nights	17 ± 10	17 ± 11	−0.030	89	.291	0.00
Weekends^a	26 ± 22	19 ± 15	1.971	89	.052	0.42
Total	33 ± 16	24 ± 13	2.998	89	.004	0.63
Social jetlag (min)	55 ± 40	33 ± 29	3.343	110	.001	0.62

The table shows mean ± SD results from independent samples t-tests and Cohen’s d as a measure of effect size. ^aParticipants whose actigraphy data did not include at least 2 school nights and 2 weekend nights were excluded of the intraindividual variability analyses, leaving 36 control and 55 gifted participants for these analyses. df = degrees of freedom, MP = midpoint, ie, halfway between bedtime and final awakening, SE = sleep efficiency, SOL = sleep onset latency, TDC = typically developing children, TST = total sleep time, WASO = wake after sleep onset.