Study Design

How study members were selected

Study members were first selected when they were in the final year of primary schooling (P7).  The aim was for a group who would be representative of the local population at both the primary and secondary school stages.  This was made more complicated by the fact that increasing choice (‘placing requests') mean that not all pupils who leave a primary school will necessarily transfer to the same (‘associated') secondary school.

The sampling scheme therefore comprised a number of steps:

• First, a sample of 43 secondary schools was randomly selected. The secondary school selection process ensured they represented the area in terms of geographical location, denomination (Catholic or Non-denominational) and deprivation (the proportion of pupils in receipt of a clothing grant). Two independent schools were also included.

• Second, a sample of primary schools was randomly selected. The primary school selection process took into account the proportion of pupils transferring both into the selected secondaries (from associated primary schools and via parental placing requests) and out (from selected primary schools to other secondaries).

• Finally, within each selected primary school, classes (whole or composite) were randomly selected.

The sample is made up of those pupils who transferred to the selected secondary schools.

 
11 to 16 - data collected in schools

11 to 16 was school-based, collecting data during sessions in primary school classrooms and secondary school classrooms, gyms, halls and dining rooms.

At each age, study members filled in questionnaires on health, self-esteem and self image, behaviours related to health (diet, exercise, smoking, drinking, experience of drugs), family life, school, leisure activities, friends and predictions for the future.  Nurses also interviewed each of them very briefly, asking about chronic illness and parental occupation, and recorded their height, weight and respiratory function.

Additionally, at age 11, questionnaires delivered by children to their parents were completed and returned via the school in respect of 86% of study members.  These parental questionnaires covered current and earlier health history, family background and circumstances, schooling and aspirations or predictions for their child's future.  Class teachers also filled in single page questionnaires about the behaviour and achievements of the child and head teachers completed questionnaires about the school environment.

At age 15, as well as the standard self-complete questionnaires, a second session was held in all schools except one, during which study members completed an interactive, computer-administered interview about their feelings and emotions.  In this interview (the Voice-DISC), respondents use headphones to listen to questions read out to them by an interviewer and answer using the keyboard of an individual laptop computer.  11 to 16 was the first study world-wide to use the Voice-DISC with large groups of respondents. 

 
16+ - data collected after school leaving

Because 11 to 16 was school-based, home addresses were not required.  In order to follow up the cohort beyond school for 16+, permission for the school to release home addresses was obtained from parents at age 15.

During July-September 2002 a survey centre was set up at Glasgow University and study members were invited to attend at the same time as others from their old school.  This was followed by a combination of weekend survey centres in the MRC Social & Public Health Sciences Unit and schools previously involved in 11 to 16, together with home visits by nurse interviewers for those unwilling or unable to attend elsewhere.  Data collection eventually finished in April 2004.

Instead of 11 to 16 style self-complete questionnaires, study members were interviewed.  However the topics were very similar to those of 11 to 16, including physical health (conditions, symptoms etc), behaviours which affect health (diet, exercise, smoking, drinking and illicit drug use), sexual experience, lifestyles (leisure activities), youth cultural identification (such as rave, goths), family life, material circumstances, educational achievement and experience of tertiary education, training and employment.  Nurses also measured height, weight and respiratory function.  Information on feelings and emotions was gathered via the computerised Voice-DISC, as at the age 15 survey of 11 to 16.

In Spring 2006, study members were sent a brief questionnaire to complete at home and return by post.  This asked about their current health and circumstances.  It also included a section on body size and shape.

All 11 to 16 and 16+ questionnaires and interview schedules are available.

11 to 16 P7 (age 11)
Child self-completion questionnaire
Nurse interview schedule
Parental self-completion questionnaire
Class teacher self-completion
School head teacher self-completion questionnaire

11 to 16 S2 (age 13)
Teenage self-completion questionnaire
Nurse interview schedule

11 to 16 S4 (age 15)
Teenage self-completion questionnaire
Nurse interview schedule

16+ age 18-20
Interview schedule

16+ age 22
Postal questionnaire