Muilenburg JL et al. 2008 [47]

Southeastern USA

6 Public schools in 2006


Part of National youth tobacco survey

990 boys

1071 girls

Ordered logit regression

Murnghan DA et al. 2007 [48]

Prince Edward Island, Canada, 10 English high schools from 1999-2001


Not stated

3965 boys and girls

Multilevel logistic regression

Poulin CC et al. 2007 [49]

Atlantic province (Nova Scotia, New Brunswick, Prince Edward Island, Newfoundland & Labrador, Secondary schools in 2002


Single stage cluster sample stratified by grade and either health regional or school district

6403 boys

6368 girls

Two level random effect model,

Sensitivity analysis was performed using multinomial logistic regression

Ridout F et al. 2008 [50]

Hampshire and Central London, 12 Secondary schools. Data collection year not mentioned.


Convenience sampling 912 boys

853 girls

Chi-squared, logistic regression adjusted for clustering

Rodriguze D et al. 2007 [51]

USA, 5 Public schools. Data collected in 2003.

Longitudinal study over 4 years

Not stated

496 boys

467 girls


Schnohr CW et al. 2009 [52]

Denmark, Sweden, Norway, Finland, and UK secondary schools 2001-2002


Data derived from a project (The health behaviour in school children)

20,399 boys and girls

Binary logistic regression analysis stratified by country

Sinha DN et al. 2007 [53]

India (North, Eastern, Western, North East), 179 schools in 2006


Two stage cluster sampling

Schools and classes selected randomly. All students selected within classes

12086 boys and girls

Logistic regression for clustered data

Sinha DN et al. 2008 [54]

India, 6 regions: North, South, East, West, Central & North East,

2003: 818 schools

2006:179 schools,


Two stage cluster sampling

Schools selected proportional to number of students, and classes selected randomly. All students interviewed from selected classes 2003: 68,077 boys and girls

2006: 12,086 boys and girls

Logistic regression for correlated data

Thrasher JF et al. 2008 [55]

Mexico,18 Public & private schools in 2006


Proportional sampling strategy to randomly select schools & classes

3874 boys and girls

Multilevel adjusted logistic regression model, SEM

Wen X et al. 2007 [56]

Huang pu and Guangzhou, China,

6 Secondary schools in 2004


Cluster sampling of schools

2021 boys

1850 girls

Logistic regression

Wen X et al. 2008 [57]

Guangzhou, China,

3 Public schools, 1 Factory school

2 General paid private schools in 2004


Multistage sampling with stratification by school type

3957 boys and girls and 2870 parents of these students

Chi-squared & Kruskal Wallis