Walter 1988.
| Study characteristics | ||
| Methods | Study design: cluster‐RCT | |
| Participants |
School inclusion criteria: elementary schools in School District 11 in the Bronx and elementary schools in 4 school districts in Westchester County School exclusion criteria: — Student inclusion criteria: schoolchildren in 2 demographically dissimilar areas in and near New York; students in Grade 4 in the Bronx, a lower‐income borough, or Westchester County, a middle‐ and upper‐income suburb Student exclusion criteria: — Setting: school, community, urban Age group: children Gender distribution: females and males Country where trial was performed: USA |
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| Interventions |
Intervention: a special curriculum targeting voluntary changes in risk behaviour in the area of diet, PA, and smoking. Curriculum content was designed to provide the information and motivation necessary for behavioural changes, as well as training in the skills necessary to make such changes. Intervention foci (perceived susceptibility to, and severity of, health problems; perceived benefits of, and barriers to, adopting and maintaining risk reduction types of behaviour) were derived from the health belief model; skills training strategies were derived from social learning theory. Cognitive development theory provided a framework for appropriate tailoring of these constructs to children's changing maturational stages; the study progressed over a 5‐year period. The PA component of the intervention fostered adoption of a regular programme of endurance exercise. The special curriculum was taught in classrooms by specially trained regular teachers for approximately 2 hours/week throughout each school year
Comparator: — Duration of intervention: 6 years Duration of follow‐up: 6 years Number of schools: 37 Theoretical framework: PRECEDE, health belief model, social learning theory |
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| Outcomes | BMI | |
| Study registration | NCT00005406 (retrospectively registered) | |
| Publication details |
Language of publication: English Funding: non‐commercial funding (National Heart, Lung, and Blood Institute and National Cancer Institute) Publication status: peer‐reviewed journal |
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| Stated aim for study | "The aims of the study were to shift favourably the population distribution of levels of blood pressure, blood lipids, body mass, and physical fitness through appropriate modifications in diet and PA, and to reduce the number of students starting to smoke cigarettes" | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: randomisation process not reported |
| Allocation concealment (selection bias) | Low risk | Comment: all participants were allocated at a single point in time following recruitment, so at time of recruitment, allocation was not known |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Comment: no information given; likely not done |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Comment: no information given; likely not done |
| Incomplete outcome data (attrition bias) Anthropometrics, Fitness | Low risk | Comment: analyses were done to see if bias would be introduced due to attrition; average risk values were imputed |
| Selective reporting (reporting bias) | Unclear risk | Comment: no protocol paper published; trial registered retrospectively |
| Cluster RCT ‐ Recruitment bias | Unclear risk | Comment: unclear when individual participants were enrolled |
| Cluster RCT ‐ Baseline imbalance | Unclear risk | Comment: no statistical test for baseline differences |
| Cluster RCT ‐ Loss of clusters | Unclear risk | Comment: not described |
| Cluster RCT ‐ Incorrect analysis | Low risk | Quote from publication: "school rather than the student was used as the unit of analysis" |
—: denotes not reported.
BMI: body mass index.
MVPA: moderate to vigorous physical activity.
PA: physical activity.
PE: physical education.
RCT: randomised controlled trial.