. 2017 Feb 10;40(3):zsx006. doi: 10.1093/sleep/zsx006

Table 5.

Test–Retest Reliability Results and Descriptive Statistics for 12 wk of Sleep Diary Data on School Nights for 55 US Adolescents.

	Week
	1	2	3	4	5	6	7	8	9	10	11	12
Bedtime
ICC	N/A	.88^a	.87^a	.90^a	.93^a	.89^a	.85^a	.90^a	.90^a	.88^a	.88^a	.90^a
N	55	55	55	54	53	51	52	50	47	49	50	50
Mean	22:47	22:58	22:58	22:50	22:56	22:52	22:53	22:34	22:34	22:47	22:49	22:52
SD	65 min	73 min	67 min	70 min	67 min	68 min	65 min	64 min	67 min	75 min	55 min	58 min
SOL
ICC	N/A	.83^a	.85^a	.86^a	.82^a	.82^a	.78^a	.78^a	.76^a	.77^a	.72^b	.83^a
N	54	53	54	51	50	49	49	48	45	47	50	47
Mean	14 min	11 min	11 min	13 min	13 min	11 min	13 min	13 min	13 min	12 min	11 min	11 min
SD	10 min	10 min	11 min	11 min	11 min	9 min	10 min	12 min	12 min	12 min	10 min	10 min
SD
ICC	N/A	.80^a	.71^b	.87^a	.83^a	.81^a	.59	.85^a	.80^a	.88^a	.84^a	.82^a
N	53	52	51	47	49	46	44	44	44	44	44	43
Mean	7 h 25 min	7 h 34 min	7 h 39 min	7 h 38 min	7 h 38 min	7 h 37 min	7 h 51 min	7 h 31 min	7 h 43 min	7 h 35 min	7 h 43 min	7 h 30 min
SD	72 min	71 min	72 min	72 min	77 min	71 min	56 min	62 min	65 min	59 min	74 min	56 min

ICC, intraclass correlation coefficient; N, number; N/A, not applicable; SD, sleep duration; SD, standard deviation; SOL, sleep onset latency; WUT, wake up time.

^aIndicates excellent reliability (ICC ≥ .75).

^bIndicates good reliability (ICC = .60–.74).