Table 2

Excessive internet use, sleep duration, frequency of physical activity and absences from school for adolescent boys and girls

VariableBoysGirls
Excessive internet use scale,* mean (95% CI)1.79 (1.78 to 1.80)1.96 (1.95 to 1.97)
Sleep duration, mean (SD)
 Hours on weekdays8.1 (1.3)8.0 (1.1)
 Hours on weekends9.2 (1.5)9.3 (1.3)
Overall physical activity per week,† n (%)
 None2354 (5.6)1637 (3.8)
 On ≤3 days11 823 (28.1)13 551 (31.1)
 On 4 to 6 days17 241 (41.0)20 301 (46.6)
 Every day10 617 (25.3)8114 (18.6)
Vigorous physical activity per week,* n (%)
 <1 hour6741 (16.1)6512 (15.0)
 1 to 3 hours15 451 (36.9)17 892 (41.1)
 4 to 6 hours9677 (23.1)10 717 (24.6)
 ≥7 hours9971 (23.8)8427 (19.4)
Frequency of unexcused absences,* n (%)
 Low28 895 (68.8)32 511 (74.7)
 Moderate11 405 (27.2)9552 (22.0)
 High1675 (4.0)1458 (3.4)
Frequency of medical absences,* n (%)
 Low32 454 (77.3)32 104 (73.7)
 Moderate8180 (19.5)9780 (22.5)
 High1335 (3.2)1663 (3.8)
  • All differences between genders were significant at p<0.001 level.

  • *The range of possible scores on the excessive internet use scale is 1–4, with higher scores indicating more problematic internet use.

  • †Data on overall physical activity were available for 85 638 participants (99.3% of total), vigorous physical activity for 85 388 (99.0%), unexcused absences for 85 491 (99.1%) and medical absences for 85 510 (99.1%).

  • CI, confidence interval; SD, standard deviation.