Methods
Study setting and participant eligibility
All state primary schools in theWest Midlands (UK) which
included school years 1 to 5 (children aged 5 to 10 years)
and that were within a 35 mile radius of the University
of Birmingham were eligible for inclusion (n = 980). To
ensure sufficient representation in the sample to enable
sub-group analysis by minority ethnic group, school populations
were stratified by ethnic mix including White, South
Asian (comprising Indian, Bangladeshi and Pakistani)
and Black (including African and Caribbean), with the
remainder being classified as “Other” ethnicity. School
populations were dichotomised as being in the top 80th
percentile in terms of South Asian or Black pupil representation,
or not. The sampling strategy used a weighted
random sample so that schools with a higher minority
ethnic population (in top 80th percentile for South Asian
or Black) had an increased chance of being sampled with
a ratio of 3:1. Given the relatively large number of clusters
(>50) the sampling strategy was also balanced to take account
of three other important factors to ensure a range
of characteristics are represented. These were: proportion
of children eligible for free school meals (FSM) as an indicator
of socio-economic make-up of the pupils, school
size and urban/rural location of the school. Using this
method, 200 schools were selected and ordered using
a random number generator. Of these, 7 were excluded
as they did not fit the eligibility criteria. The
remaining schools were sequentially invited to participate,
and 148 were approached until the required sample
size (54 schools) was achieved. Of the 148 schools
approached, 4 did not respond and 90 declined to
participate.
Exclusion criteria
Schools with fewer than 17 pupils in the relevant year
group (minimum cluster size), or those that were in special
measures (status applied by the Office for Standards
in Education when it considers that a school fails to supply
an acceptable level of education and appears to lack
the leadership capacity necessary to secure improvements)
were excluded.
School recruitment process
Schools were approached by letter, followed by a phone
call and a visit to interested schools. All participating
schools (control and intervention) receive a financial reimbursement
(£190) following each period of pupil measurement
to compensate for staff time spent on the study.
Regular newsletters are sent to participating schools to
maintain engagement.
Recruitment of study participants
All Year 1 pupils (aged 5 to 6 years) in participating
schools were eligible to take part. An invitation letter,
information leaflet and consent form were distributed
through schools to parents/carers of eligible pupils.
Trial intervention
The WAVES study intervention programme has four
components (outlined below) delivered over 12 months.
There is also a termly family newsletter to reinforce the
messages delivered through the various components.
The schools are used as the platform for disseminating
information, targeting intervention children and their