Table 2

 Validity assessment of included studies

StudyStudy design sampling sampleAge or gradeIndividual level variables in the multilevel models
Smoking habits and alcohol use
Johnson and Hoffmann, USA, 2000Longitudinal studyGrade 8–10Sex, race/ethnicity, school drop out, college plans, work >10h/week, grade point average, self esteem, school misconduct, positive school attitude, peers, negative peer association, two biological parents at home, parental support, parental education
Probability sampling
Two cohorts: 16454 pupils in 1012 schools
13840 pupils in1397 schools (wave two)
Maes and Lievens, Belgium, 2003Cross sectional study13 and 16 yearsAge, sex, type of education, smoking behaviour of father/mother, school results, attitude towards school, school attendance, integration with friends, physical health, mental health, integration with family, repeating classes, relationship with teacher, frequently being drunk
Non-probability sampling
3225 pupils in 29 schools
Moore et al, Great Britain, 2001Cross sectional studyGrade 11Sex, age, family structure, family affluence, mother smoker, best friend smoker, high parental expectations, alienation (easy to talk to parents)
Probability sampling15–16 years
1375 pupils in 55 schools
Pinilla et al, Spain, 2002Cross sectional study13–14 yearsAge, sex, number of people at home, spending money, interest in studies, alcohol consumption, tobacco consumption by peer group and by family members, knowledge about tobacco, attitudes towards tobacco
Probability sampling
1887 pupils in 30 schools
Reeder et al, New Zealand, 1999Longitudinal study14–15 yearsSex, ethnicity
Non-probability sampling
5834 pupils in 15 schools
Rountree P, USA, 1999Cross sectional studyGrade 6–12Sex, age, race, peers drink, religious commitment, school attachment
Probability sampling
2295 pupils in 53 schools
School achievement
Battistich V, USA, 1995Cross sectional studyGrade 3–6 (elementary school)Sex, ethnicity, grade, sense of community
Non-probability sampling
4515 pupils in 24 schools
Blau J, USA, 2001Longitudinal studyGrade 10–12(Only from grade 10) race, sex, SES, scores in mathematics and reading, intact family, locus of control, educational expectations, academic motivation
Probability sampling
2435 pupils in 146 schools
Webster B, Australia, 2000Cross sectional studyGrade 7–8Sex, SES, attitudes towards science and mathematics, career aspirations
Sampling unclear13 years
12852 pupils in 161 schools
Young D, Australia, 1998Cross sectional studyGrade 8–10SES, sex, race (Aborigine), English speaking, academic self concept, general self concept, grade
Probability sampling
3397 pupils in 28 schools
Problem behaviour/wellbeing
Konu A, Finland, 2002Cross sectional studyGrade 8–9Sex, grade, family structure, unemployment, school conditions, social relations, means for self fulfilment, health status
Sampling unclear14–16 years
87341 pupils in 458 schools
Mooij T, Netherlands, 1998,Longitudinal studyGrade 3–4Sex, religious affiliation, ethnicity, intelligence, personality dimensions, school achievements, school behaviour, school motivation, parents living together, educational level of parents, occupational level of parents
Probability sampling
1998 pupils in 71 schools
George R, USA, 2000Longitudinal studyGrade 8–10Race, sex, SES, school climate, lifestyle, daily smoking (grade 8), heavy drinking (grade 10)
Probability sampling
17500 pupils in 1500 schools
Roeger L, Australia, 2001Prospective longitudinal studyGrade 8–10No individual level variables presented
Non-probability sampling13–15 years
2489 pupils in 25 schools
van den Oord E, Netherlands, 1999Longitudinal study4.8 years (mean)Sex, age
Non-probability sampling
1162 children in 51 schools
Wilcox P, USA, 2001Cross sectional studyGrade 6–12Age, sex, race, SES, general problem behaviour, gun ownership/use, parental gun ownership/use, peers carrying weapon to school, family dysfunction, school attachment, religious involvement, threatened at school, property victimisation at school, fear at school
Sampling unclear
6169 pupils in 21 schools
Physical activity
Zhu W, USA, 1997Cross sectional studyGrade 3–4Sex, age
Sampling unclear6–9 years
2372 pupils in 54 schools