NGHC: Prevention of Chronic Disease (2013)
Harris KC, Kuramoto LK, Schulzer M, Retallack JE. Effect of school-based physical activity interventions on body mass index in children: A meta-analysis. CMAJ. 2009 Mar 31;180(7): 719-726.
PubMed ID: 19332753
- Randomized and non-randomized controlled trials with appropriate control groups
- School-based exercise or physical activity intervention
- Control group could not receive intervention
- School age (five to 18 years)
- Objective height and weight data
- Minimum study duration of six months
- If study results are published in more than one article, BMI data were included only once
- No language restriction
- For meta-analysis: Complete BMI data.
- Not meeting inclusion criteria
- For meta-analysis: Incomplete BMI data.
- Four electronic databases searched:
- MEDLINE (January 1966 to September 2008)
- Cochrane CENTRAL Register of Controlled Trials (up to September 2008)
- EMBASE (January 1980 to September 2008)
- CINAHL (January 1982 to September 2008)
- Hand-searched the electronic versions of the following journals from January 2003 through September 2008:
- Journal of Pediatrics
- Archives of Pediatric and Adolescent Medicine
- Authors searched the reference lists of included articles and relevant reviews for additional studies
- The following MeSH terms were searched: “Obesity” or “overweight” and “schools” and “child” or “adolescent” and “exercise.”
Systematic review with meta-analysis on subgroup of studies.
- Heterogeneity of summary estimates was assessed using the I2 statistic
- Publication bias was assessed using a funnel plot
- Multiple one-way sensitivity analyses were completed to assess the robustness of the results
- Additionally, results were compared for:
- Studies with and without co-interventions
- Studies longer and shorter than one year
- Studies with both girls and boys vs. those with only one sex
- Randomized controlled trials vs. controlled clinical trials.
Timing of Measurements
Included studies were published between 1996 and 2007.
School-based physical activity intervention.
- Sex of subjects
- Design of trial
- Duration of intervention
- Presence of co-interventions
- Quality of intervention (measured using Jadad criteria and the Cochrane Effective Practice and Organization of Care Review Group criteria).
- Initial N: 398 studies initially identified
- Attrition (final N): 18 unique studies included in the systematic review, 15 studies used in the meta-analysis. The sample of studies comprised analysis on 18,141 children.
- Age: Five to 18 years
- Ethnicity: Summary characteristics not reported.
Other Relevant Study Characteristics
- 15 studies included some measure of physical activity
- No studies objectively measured adherence to program at individual level
- Three studies included only physical activity intervention and 15 studies included co-intervention (e.g., classroom nutrition education, health education or family involvement)
- Study duration ranged from six months to three years (median 18.5 months).
- US: 12 studies
- Canada: Three studies
- Australia, Chile, Sweden: One study.
- The change in BMI was not statistically significant between children who received school-based physical activity interventions and those who did not (weighted mean difference was -0.05kg/m2; 95% CI: -0.19 to 0.10)
- The result was statistically heterogeneous. There was no indication of publication bias.
- When only RCTs were included in the meta-analysis, difference in BMI change was still not significant (though the results were no longer statistically heterogeneous)
- The presence of co-interventions did not affect the results
- The duration of the study did not affect the results
- Study quality did not affect the results
- Sex of students did not affect the results.
- Body composition did not improve with participation in a school-based physical activity program
- Nonetheless, it is still important to promote school-based physical activity programs because studies have demonstrated significant benefits in other areas (e.g., increasing lean muscle mass, bone density and aerobic capacity as well as improving flexibility).
- sensitivity analysis
Quality Criteria Checklist: Review Articles
|1.||Will the answer if true, have a direct bearing on the health of patients?||Yes|
|2.||Is the outcome or topic something that patients/clients/population groups would care about?||Yes|
|3.||Is the problem addressed in the review one that is relevant to dietetics practice?||Yes|
|4.||Will the information, if true, require a change in practice?||???|
|1.||Was the question for the review clearly focused and appropriate?||Yes|
|2.||Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described?||Yes|
|3.||Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased?||Yes|
|4.||Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible?||Yes|
|5.||Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined?||Yes|
|6.||Was the outcome of interest clearly indicated? Were other potential harms and benefits considered?||Yes|
|7.||Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described?||Yes|
|8.||Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included?||Yes|
|9.||Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed?||Yes|
|10.||Was bias due to the review's funding or sponsorship unlikely?||Yes|