Operationalisation of study variables on psychosocial and behavioural factors
| Variable | Codes | |
|---|---|---|
| Psychosocial determinants (social context of parents, school, peers) | ||
| Relationship with mother (how easy/difficult to talk to mother) | 0=Very easy/easy | 1=Difficult/very difficult/don't see/have |
| Relationship with father (how easy/difficult to talk to father) | 0=Very easy/easy | 1=Difficult/very difficult/don't see/have |
| Classmate support | 0=High support | 1=Medium; 2=low |
| Satisfaction with school | 0=Like it a lot/like it a bit | 1=Don't like it very much/don't like it at all |
| Academic achievement | 0=Very good/good | 1=Average/below average |
| School-related stress | 0=Not at all/a little | 1=Some/a lot |
| Number of friends of the same sex | 0=More than 2 friends | 1=None/one friend |
| Number of friends of the opposite sex | 0=More than 2 friends | 1=None/one friend |
| Time with friends after school | 0=2 days or more | 1=Less than 2 days |
| Support of the best friend (how easy/difficult to talk to best friend) | 0=Very easy/easy | 1=Difficult/very difficult/don't have |
| Health-related behaviours | ||
| Smoking | 0=Less than once a week/never | 1=At least once a week |
| Alcohol consumption | 0=Less than every week | 1=At least every week |
| Physical activity (MPVA) | 0=At least 60 min on at least 5 days | 1=Fewer days |
| Consumption of fruits | 0=Daily | 1=Less than daily |
| Consumption of vegetables | 0=Daily | 1=Less than daily |
| Consumption of sweets | 0=Less than daily | 1=Daily |
| Consumption of soft drinks | 0=Less than daily | 1=Daily |
| Eating breakfast on schooldays | 0=Every school day | 1=Less than every school day |
| Watching TV—weekdays and weekends | 0=Less than 2 h daily | 1=More than 2 h daily |
| Playing PC games—weekdays and -ends | 0=Less than 2 h daily | 1=More than 2 h daily |
| PC (homework, etc)—weekdays and weekends | 0=Less than 2 h daily | 1=More than 2 h daily |
MPVA, moderate to vigorous physical activity.