Pediatrics and Physical Activity

Study Design:
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Quality Rating:
Research Purpose:
  1. To define age-specific data for the major risk factors for cardiovascular diseases in youth.
  2. To develop methods for the prevention and early correction of these risk factors.
  3. To evaluate the effectiveness of the intervention.
Inclusion Criteria:

11-year-old schoolchildren residing in two Moscow administrative districts.

High blood pressure designated as diastolic or systolic blood pressure levels in upper 5% of distribution curve on at least one measurement, children in upper 15% of distribution curve for BMI assumed to be overweight, serum total cholesterol and triglyceride levels in upper 10% of distribution curves regarded as elevated, HDL cholesterol level in lowest 10% of curve regarded as low, individuals smoking at least one cigarette per week classified as regular smokers.
Exclusion Criteria:

None specified.

Description of Study Protocol:

Intervention group selected from one administrative district; reference group from another district established.

Intervention group divided into three subgroups : first focused on obesity, second on smoking and physical activity, third on lipids; intensive smoking control measures undertaken in one school for grades 5-10 (age 12-16 years).

Intervention program targeted towards schoolchildren, parents, and teaching staff.

Program consisted of distribution of health education materials developed at Inst. of Preventive Cardiology, lecture courses, round-table discussions, movies, and slide shows.

Compliance determined through repeat interviews, anthropometric measurements & annual screenings.

Intervention aimed at smoking, overweight and high blood pressure: 3 years; intervention aimed at blood plasma lipids: 1 year.

Data Collection Summary:


  • BMI,
  • subscapular skinfold thickness,
  • systolic blood pressure (all triple measurement),
  •  cigarette smoking,
  • blood thiocyanate.
  • Among subsample of boys: LDL cholesterol, plasma cholesterol, triglycerides, atherogenicity index (AI = (Chol – HDL)/HDL).

No blinding indicated.


  • Preventive measures directed at excess body mass, systolic blood pressure, blood lipids (among boys), cigarette smoking, physical inactivity, including lecture, discussion, and distribution of health education materials.

Control Variables

  • Age,
  • physical activity (determined by questionnaires and 7-day pedometry).
  • Dietary patterns studied in subsample using 24 hour recall and food models.

Statistical Analysis

No discussion provided. Regression analysis for subsample plasma lipid levels.

Description of Actual Data Sample:

Original Sample: 2574 children 11 years of age in intervention group; 2241 children 11 years of age in reference group.

Subsample of boys for plasma lipid analysis: 569 from intervention group, 608 from reference group.

Withdrawals/Drop-Outs: Not described.

Final Sample:

Total 4213 boys and girls 11 years of age - 2250 children in intervention group (87.4%), 1963 children in reference group (87.6%).

Subgroups: 477 boys from intervention group (83.8%), 528 from reference group (86.8%)

Female/male not specified.

Location: Moscow

Race/Ethnicity: Not specified.

SES: Not specified.

Summary of Results:

Baseline examination did not reveal significant differences in blood pressure, mean BMI, triglyceride and HDL levels; less than 1% smoked in either group.

Blood thiocyanate correlated with number of cigarettes smoked; cholesterol level significantly higher in intervention group at baseline. Dietary pattern analysis showed increased fat and carbohydrate consumption with increased BMI.

Increase in BMI lower in intervention group, but not statistically significant.

Subscapular skinfold increased in both males and females; increase more pronounced in reference group and statistically significant for all 3 years in males, first 2 years in females.

Increase in mean systolic blood pressure higher in reference group for both sexes compared to intervention group, significant for females all 3 years and for males first 2 years.

Significant decrease in number of male smokers who attempted smoking for first time (triers) and in number who smoked already; females had positive effect only among triers. Prevention effect more pronounced among younger children.

In subsample, LDL levels increased among lower 25% and decreased among upper 25% of distribution curve. Increases in mean cholesterol and triglycerides observed in reference group, decreases in intervention group. HDL decreased in both groups; atherogenicity index increased in reference group, decreased in intervention group.

Author Conclusion:

(limited discussion)

Overall successful development and implementation of comprehensive program for prevention of atherosclerosis precursors in children and adolescents.

Additional study needed to evaluate more precisely the effectiveness of prevention efforts.

Funding Source:
Government: NIH
Pharmaceutical/Dietary Supplement Company:
University/Hospital: Tampa General Hospital
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? No
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? No
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? No
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? No
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? No
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? ???
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes