Table 1.

Characteristics of independent variables

Construct	Description of questions	Responses
Academic pressure	In the past 12 months, how often did you feel unhappy because of stress/pressure from school?	“none” = ”low”, “rarely or sometimes” = “average”, “often or always” = “high”
School achievement	How do you think your performance compares with your classmates?	“above average”, “average”, “below average” “not sure
Family structure	Who do you live with at home?	“both parents” vs other
Smoking	Have you ever tried cigarette smoking, even one or two puffs	“Yes” or “No”
Binge drinking last 30 days	During the past 30 days, on how many days did you have five or more drinks of alcohol in a row that is, within a couple of hours?	“0” or “1-30”
Physical fighting past 12 months	During the past 12 months, how many times were you in a physical fight	“0”, “1” or “2 or more times”
PE classes	In an average week when you are in school, on how many days do you go to physical education (PE) classes	“0 or 1 day” and “More days”
Exercising	During the past 7 days, on how many days were you physically active for a total of at least 60 min per day?	“0-2 days” and “More days”
Considered running away from home in last 12 months	During the past 12 months, did you ever seriously consider running away from home that is, leaving your home for 24 h or more without your parents’ permission?	“Yes” or “No”
Ran away from home in last 12 months	During the past 12 months, did you ever attempt to run away from home (for 24 h or more without your parents’ permission)?	“Yes” or “No”
Victim of bullying	During the last 12 months have you ever been (a) ‘hit, kicked, pushed, shoved around, or locked indoors?’ (b) ‘Made fun of or insulted?’ (c) ‘Excluded intentionally or prevented from participating?’ (d) ‘Made fun of with gender jokes, comments or gestures?’; ‘blackmailed for money?’ or (f) ‘bullied in some other way?’	Victims who reported at least one victimization experience in the last 12 months with a frequency of “often”
Feeling lonely	During the past 12 months, did you ever feel lonely	“Never”, “rarely or sometimes” and “often or always”
Feeling sad/hopeless	During the past 12 months, did you ever feel so sad or hopeless almost every day for 2 weeks or more in a row that you stopped doing some usual activities	“Yes” or “No”