Table 1.
Average descriptive statistics for analytical sample (N = 590)
| Variable | M or % | (SD or n) |
|---|---|---|
| Demographic and household | ||
| Sexa | ||
| Female | 53% | (315) |
| Male | 47% | (275) |
| Race/ethnicity | ||
| Black/African American | 41% | (241) |
| Hispanic and/or Latino | 25% | (148) |
| White/Caucasian | 19% | (112) |
| Other,b mixed, or none | 15% | (89) |
| Body mass index (BMI) percentilec | 73.88 | (24.96) |
| Annual household income | $65,794 | ($61,776) |
| Adolescent living arrangements | ||
| Does not live with two biological parents | 68% | (401) |
| Lives with two biological parents | 32% | (189) |
| Primary caregiver highest education completed | ||
| Less than high school | 14% | (81) |
| High school | 18% | (105) |
| Some college | 47% | (276) |
| College | 22% | (128) |
| Emotional health | ||
| Boredomd | 1.19 | (.88) |
| Lonelinessd | .52 | (.76) |
| Happinessd | 2.19 | (.90) |
| Depressive symptoms scoree | .60 | (.59) |
| School attendance | ||
| Attended school (proportion of days) | .43 | (.34) |
| Nightly sleep measuresf | ||
| Sleep duration (hrs) | 7.80 | (1.07) |
| Sleep onset (clock time) | 0:27 | (1:44) |
| Sleep midpoint (clock time) | 4:21 | (1:42) |
| Sleep offset (clock time) | 8:19 | (1:46) |
| Sleep maintenance efficiency (%) | 90.71 | (3.39) |
| Subjective sleep qualityg | 2.35 | (.50) |
| Sleep variability measuresh | ||
| Variability (SD) of sleep duration (hrs) | 1.56 | (.80) |
| Variability (SD) of sleep onset (hrs) | 1.29 | (.73) |
| Variability (SD) of sleep midpoint (hrs) | 1.22 | (.65) |
| Variability (SD) of sleep offset (hrs) | 1.57 | (.91) |
| Sleep regularity indexi | 48.49 | (13.24) |
| Social jetlag (hrs)j | 1.80 | (1.15) |
| Dietary intake | ||
| Consumed breakfast (proportion of days)k | .70 | (.33) |
aData collected at birth
bOther category includes Asian, Central American/Caribbean, Native American/Alaska Native, and/or Native Hawaiian/Pacific Islander
cCalculated based on 2000 Centers for Disease Control and Prevention (CDC) growth charts, matched for age and sex[46]
dRanges from 0 (very slightly or not at all)–4 (extremely)
eComputed from Center for Epidemiologic Studies Depression Score [47]. Range: 0 (low)–3 (high)[47]
fThe mean number of valid actigraphy nights per adolescent was 5.6 ± 1.4 (range: 3–9); IQR 5–7
gRanges from 0 (very bad)–3 (very good)
hHigher value means greater variability, except the reverse for the sleep regularity index
iCalculated based on formula from Phillips et al. [42]; ranges from 0 (low)–100 (high)
jCalculated based on formula from Wittmann et al. [43]. N = 372 (adolescent included only if provided at least one weekday and one weekend night of actigraphy; n = 372)
kThe mean number of breakfast reports per adolescent was 5.5 ± 1.4 (range: 3–9; IQR 4–7)
M, mean; hrs, hours; n, number; SD, standard deviation