Active City of Liverpool Active Schools and SportsLinx Project: a Clustered Randomised Controlled Trial
Condition: Physical Activity; Health Behavior
Study type: Interventional

Summary: 
      The purpose of the A-CLASS project was to measure the effect of the 4 hour offer on
      children's physical activity, health and physical competence.
    

Detailed description: 
      Study design

      Treatment arms in this four-arm parallel-group cluster randomised controlled trial (RCT)
      included a high intensity physical activity (HIPA) intervention group, a fundamental movement
      skill (FMS) intervention group, a physical activity signposting (PASS) intervention group and
      a control group (usual practice).

      Recruitment

      - Organisation level

      Sixteen primary schools were targeted by the research team in May-July 2006. The schools were
      targeted based on their size (student enrolment >400 primary school; >250 junior school),
      current afterschool club provision (limited), school sport facilities available for use
      (bi-weekly) and socioeconomic status of the school postcode classified by postcode in the
      Index of Multiple Deprivation as deprived (IMD > 40). Signed consent was sought and obtained
      from the head teachers of the sixteen schools for pupil recruitment, study contact,
      laboratory visits during school time and access to school facilities. Eight from the sixteen
      schools were randomly selected to take part using random number allocation.

      - Individual level

      All children in year 5 in consenting schools received a verbal and written overview of the
      study through a researcher led study information session held at the respective schools.
      Children were given 2 weeks to express interest via the return of a written assent form
      (children) and parental/guardian consent form to their school teacher. Medical questionnaires
      were distributed to all children who agreed to take part in the study, and they were assessed
      for stature and body mass in order to calculate body mass index (BMI; kg/m2). BMI was used as
      guide to target the children who were overweight or may be nearing overweight according to
      BMI cut-off thresholds stipulated by Chinn and Rona (2004). Generally, 20-25 children with
      the highest BMI within each school who were free from the presence of chronic disease,
      metabolic disorders, motor or co-ordination difficulties and prescribed medications including
      steroids inhaled by asthma sufferers were then enrolled to participate in the project. There
      was no racial or gender bias in the selection of participants.

      Group assignment and Intervention

      Participating schools were randomly allocated by a computer generated procedure to one of
      four treatments to reduce risk of contamination effects across the trial.

      Data collection

      Measurements took place at three time points: at baseline (month 0; September to mid-October
      2006); end-intervention (9 months; June to mid-July 2007); and follow-up (3 years; October
      2009). At each time point participants attended University laboratories for individual
      assessments. At each time point participants' habitual physical activity was objectively
      assessed using accelerometers, and participants' fundamental movement skills were assessed at
      their respective school. Prior to laboratory visits, participants were instructed to fast for
      a minimum of 8 hours and avoid strenuous exercise for 24 hours.

      Sample size

      It was feasible to recruit eight schools and randomly assign two schools to each of the four
      arms. With an estimated number of consenting Year 5 pupils of 20 per school, the planned
      sample size was around 40 participants per arm. Allowing for 10% attrition at 9 months and a
      design effect of 1.2 to account for school-level clustering (ICC of 0.01), our effective
      sample size was 30 participants per arm. This sample size provides approximately 80% power at
      2P=0.05 to detect a targeted difference between intervention and control (3 planned
      comparisons) at the 9-month timepoint of 3 units for the total FMS skills score (based on an
      between-subjects standard deviations (SD) of 7 units and a reliability of r=0.8 over the
      timeframe of the intervention; ANCOVA model adjusting for baseline FMS score). With an
      anticipated attrition of up to 50% for the 2-year follow-up timepoint, our effective sample
      size was only 16 participants per arm. Group comparisons at this timepoint are therefore
      defined as exploratory, as we have relatively low power to detect the same effect size
      (around 50%).

      Statistical analyses

      There are too few clusters per arm to account robustly for the hierarchical data structure
      using linear mixed (multilevel) modelling, generalised estimating equations, or clustered
      robust standard errors. Therefore, data will be analysed at the individual level, with
      standard errors inflated by the square root of the design effect. The change in FMS score
      from baseline to post-intervention (9-months) will be compared between arms using a
      regression model (ANCOVA), adjusting for baseline FMS score and sex. There are 3 planned
      comparisons comprising each of the 3 interventions vs. usual practice. Point estimates will
      be derived together with uncertainty expressed as 90% confidence intervals. For the primary
      outcome, a purely exploratory sub-group analysis will be conducted using a
      sex-by-intervention group interaction term to examine the potential for differential
      intervention effects in boys vs. girls. Secondary outcomes will be analysed using the same
      general modelling approach, but with no inferential emphasis placed on the results. Where
      appropriate, a principled method will be applied to address missing data (e.g., multiple
      imputation or full information maximum likelihood).
    

Intervention name(s): High intensity physical activity (HIPA); Fundamental movement skill (FMS); Physical activity signposting (PASS)
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): This arm consisted of a twice-weekly after-school club at the intervention school for 26 weeks during school term time, delivered by qualified coaches. Each 60 minute session engaged participants in high-intensity vigorous activity using a combination of playground-style games and circuit training activities that aimed to keep children moving and maintain a mean heart rate above 70% of age-predicted maximum heart rate (~145 beats/min) for the session duration. Intensity was verified by heart rate monitoring. Coaches delivered and monitored sessions and increased the intensity over time to allow for the children to progress. The mean heart rate for HIPA sessions was 150 beats/min, with children spending 52 min at this intensity during the session.; This arm consisted of a twice-weekly after-school club at the intervention school for 26 weeks during school term time, delivered by qualified coaches. Each 60 minute session focused on improving two skills from the vertical jump, hop, sprint run, dodge, kick, catch, overarm throw, and strike. All skills were taught in equal quantities. Each session was designed to maximise participation and enjoyment, and consisted of various games, drills, self-learning activities, and offered numerous opportunities for practice. Skill components were taught to the children using simple learning cues, and skill related questions were used to develop purposeful feedback. The mean heart rate for FMS sessions was recorded at 141 beats/min, with children spending 55 min at this intensity during the session.; A researcher visited participants once per week in 6 weekly blocks to set an activity mission to complete outside school with family and friends. Twenty missions were set over 4 x 6 week blocks, each separated by a 6 week break. Each mission suggests a task as a prompt to participate in physical activity and decrease sedentariness during the week. Children received a sticker on a wall chart for returning the mission; children were rewarded with prizes if all missions were returned in each block. If all missions were returned in a block, a reward was given. 58% of children returned all twenty missions. In addition to the missions, pedometers were issued as a promotional tool for the duration of the project for self-monitoring of activity.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Children; Physical activity; Physical competence; Obesity; School; Health; Fundamental movement skills