Table 1.

Sample Characteristics Among Non-Hispanic Black (NHB, n = 399) and Non-Hispanic White (NHW, n = 995) Participants in the NEXT Generation Health Study, Waves 1–3.

Characteristic	NHB, Mean (SD)	NHW, Mean (SD)	p
Number of occasions smoked in the past 30 days (1–7)
Wave 1	1.15 (0.77)	1.67 (1.65)	<.01
Wave 2	1.09 (0.50)	1.68 (1.68)	<.01
Wave 3	1.12 (0.65)	1.91 (1.91)	<.01
Troubles falling asleep in the past 4 weeks (1–5)
Wave 1	2.16 (1.19)	2.50 (1.21)	<.01
Wave 2	2.15 (1.16)	2.47 (1.22)	<.01
Wave 3	2.10 (1.14)	2.33 (1.17)	<.01
Trouble staying asleep in the past 4 weeks (1–5)
Wave 1	2.21 (1.24)	2.32 (1.25)	.14
Wave 2	2.24 (1.27)	2.21 (1.21)	.71
Wave 3	2.18 (1.20)	2.21 (1.18)	.64
Difficulty getting to sleep in the past 6 months (1–5)
Wave 1	1.91 (1.33)	2.21 (1.39)	<.01
Wave 2	1.82 (1.20)	2.14 (1.36)	<.01
Wave 3	1.82 (1.15)	2.03 (1.28)	<.01
Weekday sleep duration (hours)
Wave 1	7.31 (1.21)	7.61 (0.94)	<.01
Wave 2	7.35 (1.22)	7.63 (1.00)	<.01
Wave 3	7.15 (1.04)	7.58 (1.02)	<.01
Weekend sleep duration (hours)
Wave 1	9.23 (1.79)	9.37 (1.46)	.17
Wave 2	9.30 (1.84)	9.32 (1.52)	.89
Wave 3	8.96 (1.74)	9.06 (1.41)	.33
Weekday mid-sleep time
Wave 1	2:28 am	2:27 am	.64
Wave 2	2:30 am	2:35 am	.13
Wave 3	2:39 am	2:44 am	.14
Weekend mid-sleep time
Wave 1	5:25 am	5:02 am	<.01
Wave 2	5:19 am	5:05 am	.01
Wave 3	5:19 am	5:06 am	.01
Gender (female)	61.9%	54.2%	<.01
Parent education (>high school)	62.4%	77.2%	<.01
Snoring or sleep apnea at W1	31.1%	29.1%	.45
Consumed alcohol in the past 30 days at Wave 1	25.3%	34.4%	<.01
Consumed soda in the past 30 days at Wave 1	83.5%	78.6%	<.01
Body Mass Index at Wave 1	25.09 (6.15)	24.29 (5.45)	.02
Depressive symptom score at Wave 1	2.29 (0.86)	2.28 (0.82)	.82

Percentages were presented for categorical variables. T-tests and chi-square tests were used to test the differences between NHB and NHW.