Table 1.
Demographics and sleep variables (n=284)
| Missing, na | na (%) or mean (sd) | |
|---|---|---|
| Age (in years) | 24 | 15.2 (0.3) |
| Sex | 23 | |
| Male | 119 (45.6%) | |
| Female | 142 (54.4%) | |
| Racial/ethnic categorization (check all that apply) | ||
| American Indian or Alaskan Native | 24 | 8 (3.1%) |
| Asian | 24 | 11 (4.2%) |
| Black, African, or African American | 24 | 10 (3.9%) |
| Hispanic or Latino/a | 19 | 8 (3.0%) |
| Native Hawaiian or other Pacific Islander | 24 | 2 (0.8%) |
| White or Caucasian | 24 | 244 (93.4%) |
| Something else | 24 | 2 (0.8%) |
| Parent education | 41 | |
| Finished college | 204 (84.0%) | |
| High school or some college | 39 (16.1%) | |
| Qualify for free or reduced-price lunch | 31 | |
| Yes | 17 (6.7%) | |
| No | 186 (73.5%) | |
| I don’t know | 50 (19.8%) | |
| School night sleep onset | 0 | 10:29 PM (52.7 min) |
| Weekend night sleep onset | 9 | 11:40 PM (80.6 min) |
| School night sleep offset | 0 | 6:15 AM (39.2 min) |
| Weekend night sleep offset | 9 | 8:53 AM (80.4 min) |
| School night sleep duration (hours) | 0 | 7.8 (1.0) |
| Weekend night sleep duration (hours) | 9 | 9.2 (1.3) |
| Weekend night-school night sleep duration differenceb, continuous (hours) | 9 | 1.5 (1.5) |
| Weekend night-school night sleep duration differenceb, categorical | 9 | |
| > 0.5 hours shorter on weekend nights | 19 (6.9%) | |
| 0.5 hours shorter to 0.5 hours longer on weekend nights | 48 (17.5%) | |
| 0.5–1.5 hours longer on weekend nights | 76 (27.6%) | |
| 1.5–2.5 hours longer on weekend nights | 67 (24.4%) | |
| >2.5 hours longer on weekend nights | 65 (23.6%) | |
| School night sleep midpoint | 0 | 2:22 AM (35.9 min) |
| Weekend night sleep midpoint | 9 | 4:17 AM (70.6 min) |
| Weekend night-school night sleep timing differencec, continuous (hours) | 9 | 1.9 (1.0) |
| Weekend night-school night sleep timing differencec, categorical | 9 | |
| < 1 hour later on weekend nights | 57 (20.7%) | |
| 1–2 hours later on weekend nights | 92 (33.5%) | |
| 2–3 hours later on weekend nights | 83 (30.2%) | |
| >3 hours later on weekend nights | 43 (15.6%) |
Min = minutes
Number of participants with missing values for that variable only.
Weekend night-school night sleep duration difference refers to the difference in weekend night and school night sleep duration (weekend night duration – school night duration), so that a positive difference corresponds to longer duration on weekend nights compared to school nights and a negative difference corresponds to a shorter duration on weekend nights.
Weekend night-school night sleep timing difference refers to the difference in weekend night and school night sleep timing (weekend night midpoint – school night midpoint), so that a positive difference corresponds to later midpoint on weekend nights than school nights and a negative difference corresponds to an earlier midpoint on weekend nights.