Table 1.
Descriptive characteristics of the study sample by gender (mean±SD unless otherwise specified)
| n | Missing | All | n | Girls | n | Boys | Sig. | |
| P value | ||||||||
| Total | 1139 (100) | 580 (51.0) | 558 (49.0) | |||||
| Age (year) | 1139 | 0 | 13.4±0.3 | 13.4±0.3 | 13.4±0.4 | 0.147 | ||
| Parental education, >12 years n (%) | 1102 | 37 | 730 (66.2) | 371 (65.9) | 358 (66.5) | 0.483 | ||
| Student country of birth, Sweden n (%) | 1129 | 10 | 967 (85.7) | 490 (84.9) | 476 (86.4) | 0.758 | ||
| BMI status* | 1135 | 4 | 580 | 554 | 0.203 | |||
| Underweight n (%) | 89 (7.8) | 38 (6.6) | 51 (9.2) | |||||
| Normal weight n (%) | 815 (71.8) | 430 (74.1) | 384 (69.3) | |||||
| Overweight n (%) | 179 (15.8) | 89 (15.3) | 90 (16.2) | |||||
| Obese n (%) | 52 (4.6) | 23 (4.0) | 29 (5.2) | |||||
| BMIsds† | 1134 | 5 | 0.36±1.23 | 580 | 0.45±1.11 | 554 | 0.26±1.35 | 0.012 |
| Sedentary time (min) | ||||||||
| SED (average week) | 903 | 236 | 602.0±66.6 | 490 | 608.9±62.65 | 413 | 593.7±70.2 | <0.001 |
| SED bouts over 10 min | 903 | 236 | 122.7±63.6 | 490 | 132.8±63.2 | 413 | 110.7±62.2 | <0.001 |
| SED leisure time (weekdays) | 1054 | 85 | 324.8±69.3 | 548 | 330.0±63.5 | 506 | 319.2±74.7 | 0.011 |
| SED leisure time (weekend) | 916 | 223 | 539.4±84.7 | 497 | 533.8±80.0 | 419 | 546.1±89.6 | 0.029 |
| SED school time | 1054 | 85 | 291.9±37.5 | 548 | 301.7±35.7 | 506 | 281.2±36.5 | <0.001 |
| MVPA time (min) | ||||||||
| MVPA (average week) | 903 | 236 | 52.0±19.0 | 490 | 49.5±17.7 | 413 | 54.9±20.1 | <0.001 |
| MVPA leisure time (weekdays) | 1054 | 85 | 31.6±15.0 | 548 | 30.9±13.8 | 506 | 32.3±16.1 | 0.145 |
| MVPA leisure time (weekend) | 916 | 223 | 37.9±25.3 | 497 | 36.8±23.3 | 419 | 39.1±27.4 | 0.156 |
| MVPA school time | 1054 | 85 | 26.5±11.2 | 548 | 23.2±9.6 | 506 | 30.1±11.7 | <0.001 |
| Reached the MVPA recommendations n (%) | 903 | 236 | 273 (30.2) | 490 | 121 (24.7) | 413 | 152 (36.8) | <0.001 |
| Accelerometer wear time | 903 | 236 | 490 | 413 | ||||
| Wear time (average week) | 792.6±60.8 | 796.0±58.1 | 788.5±63.8 | 0.067 | ||||
| Total included valid days (average week) | 6.0±1.1 | 6.2±1.0 | 5.8±1.1 | <0.001 | ||||
| Organised sports | ||||||||
| Participated in organised sports n (%) | 1094 | 45 | 788 (72.0) | 396 (71.4) | 391 (72.7) | 0.626 | ||
| Screen time (weekdays) | 1126 | 13 | 575 | 550 | 0.842 | |||
| ≤2 hours n (%) | 360 (32.0) | 179 (31.1) | 180 (32.7) | |||||
| 3–4 hours n (%) | 515 (46.0) | 267 (46.4) | 248 (45.1) | |||||
| ≥5 hours n (%) | 251 (22.3) | 129 (22.4) | 122 (22.2) | |||||
| Screen time (weekend) | 1123 | 16 | 576 | 546 | <0.001 | |||
| ≤2 hours n (%) | 178 (15.9) | 70 (12.2) | 108 (19.8) | |||||
| 3–4 hours n (%) | 412 (36.7) | 238 (41.3) | 173 (31.7) | |||||
| ≥5 hours n (%) | 533 (47.5) | 268 (46.6) | 265 (48.5) | |||||
| Mental health | ||||||||
| SCAS-S | 1073 | 66 | 13.7±7.9 | 547 | 16.6±8.0 | 525 | 10.6±6.6 | <0.001 |
| Kidscreen-10 | 1097 | 42 | 39.6±5.4 | 562 | 38.3±5.2 | 534 | 41.0±5.3 | <0.001 |
| Kidscreen-10‡ | 1097 | 42 | 49.6±9.0 | 562 | 47.3±7.5 | 534 | 51.9±9.8 | <0.001 |
*BMI status according to, IOTF 2012.
†BMIsds according to a Swedish reference standard.
‡International T-values based on Rasch person parameter.
BMI, body mass index; BMIsds, body mass index SD score; MVPA, moderate-to-vigorous physical activity; SCAS-S, Short version of the Spence Children’s Anxiety Scale; SED, sedentary time.