PWM: School-based Programs to Prevent Overweight (2006)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To study the effects of the Heart Smart cardiovascular school health promotion program which targeted the total school environment with a multidisciplinary approach to prompt the school’s varied institutions to implement changes in curriculum, school lunch, and physical education. Study objectives:

  • Adoption of heart healthy diet consistent with AHA guidelines (fat <30% energy, sat fat <10% energy, NaCl <5g/d, attainment & maintenance of IBW),
  • Adoption of physical activity patterns & behavioral skills conducive to lifetime fitness
  • Deterred onset of smoking & other unhealthful behaviors through promotion of self0esteem & cognitive/attitudinal awareness
Inclusion Criteria:

Not stated; site of schools selected because of the mixed racial & SES distribution; OB definition not stated (15% of 556 children defined as OB)

Exclusion Criteria:

Not stated

Description of Study Protocol:

Each of 4 schools was randomly assigned (method not stated) to control or intervention. Program components were implemented over 2 ½ y and included:

CVD risk factor screening:  blood lipids, anthropometry and BP 3 times/y

Heart healthy curriculum: CV anatomy/physiology, nutrition/eating behavior, PA/exercise behavior, and behavioral/coping skills for 15-35 h/y per grade by classroom teachers as a science course

Staff development:  2 d workshop, curriculum materials, bimonthly booster sessions, optional after-school sessions

Modified school lunch: heart healthy foods offered (e.g., salad bar)  - rather than served - so sample self-selected; menus designed to provide 1/3 RDA for energy [˜600 kcals], 29 g fat, 6 g sat fat, <600 mg Na; encouraged healthy bag lunches also

Superkids-Superfit Exercise Program: 12 didactic lessons + aerobic activities designed to increase level of fitness through personalized, noncompetitive leisure-time activity + modified PE taught by PE staff

Parent outreach: Health Advisory Committee, Parent volunteer program, newsletter

Family health promotion: 12-w program promotion eating & exercise lifestyle changes in families of children at high risk for CVD [>90th percentile for lipids, wt, and/or blood pressure from CVD risk factor screening.

Statistical Analysis:  Not described

Data Collection Summary:

Dependent Variables

  • School food service recipes (nutrient content)
  • Acceptability of foods (plate waste)
  • Fitness (1-mile run/walk time)
  • CVD health knowledge (test)
  • CVD risk factor screening (serum lipids/lipoproteins, TSF, SSF, waist circ, BP)


Independent Variables

  • Heart healthy curriculum
  • Staff development
  • Modified school lunch
  • Exercise program
  • Parent outreach

Control Variables


Description of Actual Data Sample:

Original Sample: 870 eligible 4th & 5th graders at 4 schools (2 control & 2 intervention)


Withdrawals/Drop-Outs: 314 did not receive parental consent and 26 did not present for full year screening? (numbers difficult to follow); screening non-participants in intervention schools scored lower on knowledge test scores than participants (p<0.05)

Final Sample: 530 students (61%); physiologic data on 136 students?

Location: Jefferson Parish (County), New Orleans, LA

Duration:  says 2 ½ y study, but shows participation rates for 1 y (1985-1986 school year)

Race/Ethnicity: In public schools - 58%W, 32% AA, 2% H, 10% other (mostly Vietnamese)

SES:  not stated

Summary of Results:

School lunch:

  • decreased saturated fat (74% less in I vs. C schools)
  • decreased simple sugars (37% less)
  • decreased sodium (65% less )
  • (p= ?)

Physical fitness:

  •  in boys (p<0.01),
  • 0 change in girls

CVD health knowledge: (p=?)

  • ? change (+22% and +8% in I screening participants and non-participants; +13% and +4% in C screening participants and non-participants, respectively)

Self-esteem/health responsibility:

  • ? change (not assessed?)


  • ? change (results presented pictorially but statistical significance not discussed)
  • ? change in ponderal index (wt/ht3)
  • ? change in skinfolds (TSF, SSF)
  • ? change in waist circ

(results not presented for other anthropometry measures)

Blood Lipids:

  •  HDL (p<0.05)
  • ? change in other lipids

(results not presented)

Associations: (p=?)

  • Heart healthy school lunch selection associated with reduction in ponderosity (81% of children in quartile showing greatest reduction in ponderosity (n=32) selected >3 CVD healthful foods vs. with 47% in quartile with the least reduction)
  • Heart healthy school lunch selection associated with reduction in blood cholesterol (61% of children in quartile showing greatest reduction selected >3 CVD healthful foods vs. 42% in quartile with least reduction)
  • Improved fitness in boys associated with reduction in skinfolds (p<0.05), weight (r=0.45, p<0.01), and waist circ (p<0.05), systolic BP (p<0.05) [other r values in graph format only]
Author Conclusion:

The Heart Smart environmental approach to health promotion was successfully implemented by school personnel. CV healthful school lunch selections have been correlated with risk factor improvements; proper growth and development have been maintained in conjunction with planned reductions in saturated and total fat content of foods.  Exercise data show significant positive results as well.  Further, significant gains in HDL were documented in intervention schools.  The Heart Smart program demonstrates the feasibility and utility of a comprehensive CV health promotion program in the elementary school.  Behavioral changes, as initiated in the heart Smart program, have great potential for reducing the CV risk of our nation’s children.

Funding Source:
Government: NIH, National Cancer Institute
Reviewer Comments:

Strengths: Multi-component intervention and evaluation, long-term trial

Limitations: Statistical tests not described and no control for potential confounding variables, incomplete presentation of anthropometry and other outcome measures, comparison of students within C & I schools or other characteristics of C & I schools on potential confounding factors not provided; unclear duration of intervention (2 ½ vs. 1 y?); methods used for evaluation (including anthropometry) not at all or poorly described; unclear on sample size for various comparisons and unclear on number who did not return parental consent vs. did not complete study; reasons for failing to complete study not provided; emphasized importance of self-esteem and personal responsibility for health, but not evaluated, and how aimed to modify not clearly described.

Discuss importance of self-esteem and personal responsibility for health, but not evaluated, and how aimed to modify not clearly described; no program assessment (e.g., number of lessons children actually received, knowledge gained by teachers, awareness of program by parents).

Other Comments:

No blinding

Randomized by school, but data analyzed by individual

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? No
2. Was the selection of study subjects/patients free from bias? No
  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? No
  2.2. Were criteria applied equally to all study groups? No
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? No
  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? No
  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? No
  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.) ???
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? ???
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? ???
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? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? ???
  5.5. In diagnostic study, were test results blinded to patient history and other test results? ???
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? ???
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  6.6. Were extra or unplanned treatments described? ???
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? ???
  6.8. In diagnostic study, were details of test administration and replication sufficient? ???
7. Were outcomes clearly defined and the measurements valid and reliable? No
  7.1. Were primary and secondary endpoints described and relevant to the question? ???
  7.2. Were nutrition measures appropriate to question and outcomes of concern? ???
  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? ???
  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? No
  7.7. Were the measurements conducted consistently across groups? ???
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? ???
  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? ???
  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)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  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? No
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