TABLE 1.
Descriptive characteristics of the characteristics of the participants (N = 1518) from southern Sweden.
| Variables | Male n (%) | Female n (%) | Total n (%) |
| Age (N = 1518) | |||
| 13 years | 84 (5.5) | 106 (7.0) | 190 (12.5) |
| 14 years | 651 (42.9) | 661 (43.5) | 1312 (86.4) |
| 15 years | 13 (0.9) | 3 (0.2) | 16 (1.1) |
| Missing Data | – | – | – |
| Socio-economic situation (N = 1518) | |||
| Very good or good economic situation | 602 (39.7) | 625 (41.2) | 1227 (80.8) |
| Average or worse economic situation | 146 (9.6) | 145 (9.6) | 291 (19.2) |
| Missing Data | – | – | – |
| Continuous variable | Mean | Mean | Mean |
| (hr:min) (SD) | (hr:min) (SD) | (hr:min) (SD) | |
| Bedtime | |||
| Weekdays | 22.20 (0.89) | 22.15 (0.83) | 22.20 (0.86) |
| Weekends | 24.10 (1.40) | 23.45 (1.24) | 23.59 (1.34) |
| Wake up time | |||
| Weekdays | 6.41 (0.46) | 6.58 (0.48) | 6.52 (0.48) |
| Weekends | 10.05 (1.43) | 9.42 (1.19) | 9.55 (1.33) |
| Sleep Duration | |||
| Weekdays | 8.13 (0.96) | 8.01 (0.98) | 8.07 (0.97) |
| Weekends | 9.67 (1.31) | 9.71 (1.14) | 9.69 (1.23) |
| Screen time | 3.72 (2.14) | 3.06 (2.06) | 3.38 (2.12) |
| Categorical variable | n (%) | n (%) | n (%) |
| Screen time (4 h cutoff) | |||
| Less than 4 h | 375(57.2%) | 498(70.3%) | 873(64.0%) |
| 4 h or more | 281(42.8%) | 210(29.7%) | 491(36.0%) |
| Night time texting | |||
| Less than weekly | 419(75.2%) | 445(78.9%) | 864(77.1%) |
| Weekly | 138(24.8%) | 119(21.1%) | 257(22.9%) |