NGHC: Prevention of Chronic Disease (2013)
Citation:
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To examine the effects of a combined dietary and physical activity school-based program on:
- Anthropometric measures
- Nutrition and physical activity knowledge
- Preferences and fitness in low socio-economic kindergarten children.
Inclusion Criteria:
- Healthy
- Kindergarten children
- From low socio-economic status communities
- Parental consent obtained.
Exclusion Criteria:
- Unhealthy
- Non-kindergarten children
- Not from low socio-economic status communities.
Description of Study Protocol:
Recruitment
Methods of recruiting kindergartens in Sharon area, Israel, not discussed.
Design
Kindergarten classes were randomly assigned to intervention or control group by computer program. 15 classes were assigned to each group.
Blinding Used
- Technicians who performed measurements were blinded to the assignment of the kindergarten class to either the intervention or control group
- Assessors of the nutritional and physical activity knowledge and preferences questionnaires were blinded to the assignment of the kindergarten class to either the intervention or control group.
Intervention
The intervention consisted of a year-round, in-school combined nutrition and physical activity program designed by pediatricians, registered dietitians, an exercise physiologist, youth exercise coaches and the pre-school staff at the kindergarten.
- The intervention included two Healthy Day festivals for parents and children of the Intervention Group, which focused on healthy nutrition, prevention of childhood obesity and benefits of exercise in children. The festival included games for the children and parents and lectures given by the study team. The first festival occurred during the second month of the program and the second occurred toward the middle of the program.
- The nutrition component of the intervention was performed by pre-school staff. It was based on the Israeli Ministry of Education's "It Fits Me" program and was designed primarily to improve nutritional knowledge. The pre-school teachers used short lectures and talks, games and story reading to teach on a variety of topics including food groups, vitamins, healthy food choices, food preparation and cooking methods and fast-food vs. home cooking. Additionally, monthly nutrition information flyers were sent home with the kindergarten children. Children were asked to share the information with their parents and parents were asked to discuss it with their children.
- The physical activity component of the intervention included 45 minutes per day of exercise, six days a week. Once a week, the training was directed by a professional youth coach. During the rest of the week, pre-school staff directed the training. Exercise was designed primarily as games and included mostly endurance-type activities. Children were also encouraged to increase their after-school physical activity and reduce sedentary activities.
Statistical Analysis
- Baseline differences between the control and intervention groups were determined using a two-sample T-test
- Effects of the intervention on body weight, height, BMI, BMI percentiles, nutrition and physical activity knowledge and preferences and fitness between the intervention and control participants were compared using a two-way repeated measures analysis of variance. To ensure no class effect, a mixed model analysis was performed when differences between the two groups were identified.
- The X2 test was used to determine the difference between the number of participants in each group that decreased their BMI percentile from overweight (85% to 95%) to normal weight (under 85%).
Data Collection Summary:
Timing of Measurements
Anthropometrics (height, weight and BMI), nutritional and physical activity knowledge and preferences and fitness were measured at baseline and at the end of the program (one year).
Dependent Variables
- Variable One: Weight (measured using Seca 769 calibrated scale and stadiometer)
- Variable Two: Height (measured using Seca 769 calibrated scale and stadiometer)
- Variable Three: BMI (measured using Seca 769 calibrated scale and stadiometer)
- Variable Four: Nutrition knowledge (children were presented with pairs of pictures then asked to identify the healthy choice)
- Variable Five: Physical activity knowledge (children were presented with pairs of pictures then asked to identify the healthy choice)
- Variable Six: Nutrition preferences (children were presented with pairs of pictures then asked to select the one they like best)
- Variable Seven: Physical activity preferences (children were presented with pairs of pictures then asked to select the one they like best)
- Variable Eight: Fitness (measured using a modified shuttle run test).
Control Variables
- Program adherence (monitored by study coordinator and professional youth coach)
- Teacher influence
- Parental influence
- Nutrition habits at home
- Physical activity habits at home.
Description of Actual Data Sample:
- Initial N: 795 kindergarten children
- Attrition (final N): 725 (393 male, 332 female); 70 children (8.8%) did not complete the study because they were absent on the days of follow-up measurements
- Age: 3.8 to 6.8 years.
Anthropometrics: Baseline Characteristics of Participants
| Control | Intervention | |
| Age (years) | 5.24±0.03 | 5.20±0.02 |
| Sex (M, F %) | 56/44 | 54/46 |
| Weight (kg) | 19.4±0.2 | 19.1±0.2 |
| Height (cm) | 109.0±0.3 | 108.4±0.3 |
| BMI (kg/m2) | 16.2±0.1 | 16.2±0.1 |
| BMI percentile | 62.6±1.5 | 62.6±1.4 |
|
Overweight (BMI percentile 85 to 95) |
63/349 (18.1%) |
72/376 (19.1%) |
|
Obese (BMI percentile less than 95) |
34/349 (9.7%) |
33/376 (8.8%) |
|
Overweight and obese (BMI percentile higher than 85) |
97/349 (27.8%) |
105/376 (27.9%) |
Location
Sharon area, Israel.
Summary of Results:
Key Findings
- There was a significant increase in nutrition knowledge and preference and in physical activity knowledge and preference in the Intervention Group compared with the Controlled Group
- There was a significant increase in height and weight, no change in BMI and a significant decrease in BMI percentile in both groups
- The only significant anthropometric difference between the groups following the intervention was a greater increase in height in the Intervention Group
- The overall number of overweight children decreased significantly from 72 to 49 (a 31.9% reduction) in the Intervention Group and from 63 to 54 in the Control Group (a 17.5% reduction).
Changes in Anthropometric Measures of Study Participants
| Control | Intervention | Between Group Difference | |
| Weight (kg) | 1.3±0.1 | 1.5±0.1 | |
| Height (cm) | 4.2±0.2 | 5.0±0.1 | P<0.5 |
| BMI (kg/m2) | -0.18±0.04 | -0.32±0.04 | |
| BMI % | -5.9±0.8 | -8.0±0.5 |
| Control Baseline | Control Post | Intervention Baseline | Intervention Post | |
|
Overweight BMI percentile 85 to 95 |
N=63 | N=54 | N=72 | N=49 |
Author Conclusion:
A combined dietary-physical activity school-based program delivered in low socioeconomic kindergartens improved nutrition and physical activity knowledge and preferences, improved fitness and decreased the percent of overweight children.
Funding Source:
| Not-for-profit |
|
||
| In-Kind support reported by Industry: | Yes |
Reviewer Comments:
- Variability in delivery of intervention by pre-school staff
- Reviewer is not familiar with the Israeli Ministry of Education's "It Fits Me" program. Details of nutrition intervention, including frequency of lectures, were not discussed.
- Variability among assessors performing nutrition and physical activity knowledge and preferences questionnaires.
|
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? | ??? | |
| 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) | Yes | |
| 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? | Yes | |
| 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%.) | Yes | |
| 4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | Yes | |
| 4.4. | Were reasons for withdrawals similar across groups? | Yes | |
| 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? | Yes | |
| 5.1. | In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? | Yes | |
| 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.) | Yes | |
| 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? | 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? | N/A | |
| 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? | Yes | |
| 6.5. | Were co-interventions (e.g., ancillary treatments, other therapies) described? | No | |
| 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? | ??? | |
| 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? | Yes | |
| 8.1. | Were statistical analyses adequately described and the results reported appropriately? | Yes | |
| 8.2. | Were correct statistical tests used and assumptions of test not violated? | Yes | |
| 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)? | N/A | |
| 8.5. | Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? | Yes | |
| 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? | N/A | |
| 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 | |