Table 1.
Students’ characteristics during the initial evaluation and during the pandemic.
| Before the Pandemic | During the Pandemic | Mean Difference | P | |
|---|---|---|---|---|
| Age, y | 15.0 ± 1.0 | 16.4 ± 1.1 | ||
| Sex, % female | 64 | 64 | 0 | > .99 |
| High school grade, % | ||||
| 9th | 40.4 | 0 | — | |
| 10th | 30.9 | 40.4 | — | |
| 11th | 28.7 | 30.9 | — | |
| 12th | 0 | 28.7 | — | |
| Sleeping preferences | ||||
| Bedtime, h | 22:00 (21:45–22:40) | 23:30 (22:30–24:12) | 1:30 (0:30–2:00) | <.001 |
| Sleep latency, min | 15 (10–30) | 20 (10–30) | 0 (−7 to +10) | .412 |
| Sleep duration, h | 7.4 ± 1.1 | 7.4 ± 1.1 | 0.0 ± 1.1 | .920 |
| Wake-up time, h | 6:00 (5:48–6:18) | 8:00 (7:42–8:30) | 2:00 (1:30–2:30) | <.001 |
| Social jet lag, h | 1.0 (0.4–1.5) | 0.5 (0.0–0.8) | −0.4 (−1.1 to +0.1) | <.001 |
| Questionnaires, score | ||||
| ESS | 11 (8–14.5) | 10 (6–15) | 0 (−3 to 3) | .882 |
| PSQI | 6.4 ± 2.8 | 6.8 ± 3.6 | 0.4 ± 3.0 | .166 |
| WHOQOL-BREF | ||||
| Physical | 68.9 ± 14.2 | 63.5 ± 18.2 | −5.4 ± 13.9 | <.001 |
| Psychological | 64.0 ± 15.3 | 57.0 ± 17.1 | −7.0 ± 12.7 | <.001 |
| Social | 67.8 ± 20.4 | 65.7 ± 19.5 | −2.0 ± 23.4 | .425 |
| Environmental | 73.0 ± 11.6 | 76.0 ± 13.3 | 3.0 ± 11.6 | .016 |
| MEQ | 50.5 ± 8.1 | 47.8 ± 8.8 | −2.8 ± 7.1 | <.001 |
| MEQ chronotypes, % | ||||
| Morning | 13.8 | 10.6 | — | .398 |
| Intermediate | 70.2 | 66.0 | — | |
| Evening | 16.0 | 23.4 | — |
Data are presented as means ± SDs or medians (25th–75th percentile) unless otherwise indicated. N = 94. ESS = Epworth Sleepiness Scale, MEQ = Morningness-Eveningness Questionnaire, PSQI = Pittsburgh Sleep Quality Index, SDs = standard deviations, WHOQOL-BREF = World Health Organization Quality of Life Questionnaire-abbreviated version.