Table 2.

Measures collected at baseline from young people

Domain/question topic	Purpose	Measure/source
Personal information
Gender, school year, age, DOB, place of birth, ethnicity and cohabitants	DE	Adapted from general household survey [61]
Family affluence	DE	Family affluence scale [62,63]
Substance use
Ever smoked?	CV	One question from substance initiation index [29]
Smoking status	CV	ASSIST study version of NatCen/NFER question [64]
Ever drunk a drink?	CV	NatCen/NFER [65]
Age of first drink?	CV	NatCen/NFER [65]
Frequency of drinking	CV	NatCen/NFER [65]
Ever little drunk?	CV	Adapted from HBSC questionnaire
Little drunk in last 3 months?	CV	Adapted from HBSC questionnaire
Ever really drunk?	CV	Adapted from HBSC questionnaire
Really drunk in last 3 months?	CV	Adapted from HBSC questionnaire
Ever taken drugs	CV	Adapted from HBSC / NatCen/NFER
Behaviour
Strengths and difficulties	CV	SDQ [66]
Aggressive and destructive conduct	CV	From Spoth, et al. [28]
Life at home
Things in your bedroom	CV	Adapted from young people, new media survey [67,68]
TV, computer games, computer use	CV	From HBSC questionnaire
Free time activities	CV	Modified questions from west of Scotland twenty-07 study
Family functioning	CV	Family relationship index [69,70]
Parenting/child management	CV	General child management, project family [71,72]
Parents and school	CV	Three questions, one of which is adapted from the child rearing practices measure
Family activities	CV	From HBSC questionnaire/PEACH study
General health
Sleep – difficulties	CV	From HBSC questionnaire
Getting up/bedtimes	CV	From PEACH study
Health state today	CV, HE	EQ-5D [73]
General health	CV	Kidscreen 27 [74]

Key: CV = Covariate; HE = Health Economics; DE = Demographics; IO = Immediate outcome; ST = Short term outcome; PO = Primary outcome; SO = Secondary outcome; TO = Tertiary outcome.