Table 1. Descriptive analysis of the adolescents (n = 1,457).

Variable	n (%)
Sex
Boy	791 (54.3)
Girl	666 (45.7)
Bullied at 12 yr	354 (24.3)
Bullied at 13 yr	289 (19.8)
Deliberate self-harm, age 13 yr	79 (5.4)
Play/homework with friends, age 13 yr
Never	101 (6.9)
Once in a while	276 (18.9)
Sometimes	339 (23.3)
Often	372 (25.5)
Always	369 (25.3)
≥5 h/d online in school days, age 13 yr	87 (6.0)
≥5 h/d online in days off school, age 13 yr	476 (32.7)
Variable (range)	Mean (SD)
Hours spent online, age 13 yr
School days (h)	1.48 (1.82)
Days off school (h)	4.01 (3.28)