EAL

NGHC: Prevention of Chronic Disease (2013)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine the effectiveness of a voluntary after-school program in: Decreasing body mass index (BMI) for age and for sex for children at risk of becoming overweight (85th to 94th percentiles) or overweight (over the 95th percentile), maintaining normal weight (fifth to 84th percentile), reducing waist circumference and program-related outcome measures per satisfaction questionnaires completed by participants.

Inclusion Criteria:

Elementary schools participating in the study were in the community served by the hospital implementing the study and were selected based on the school principals' willingness to accommodate an after-school program offering the Kids Living Fit intervention.

Volunteer students at participating schools were included if they:

Were willing and able to perform physical fitness activities
Were willing and able to complete food and activity study questionnaires and diaries
Were in second through fifth grade
Paid $100 fee (although the hospital provided scholarships for children identified by school principals who wanted to participate but were unable to pay the fee).

Exclusion Criteria:

Elementary schools were not selected for participation if the school principals were unwilling to accommodate an after-school program offering the Kids Living Fit intervention.

Students were excluded if they:

Were unwilling or unable to perform physical fitness activities
Were not in second through fifth grade
Were unwilling or unable to complete food and activity study questionnaires and diaries.

Description of Study Protocol:

Recruitment

Letters describing the study were sent home with students in weekly written communications between schools and parents.

Design

A quasi-experimental design was used for this 24-week study
Students at the four participating public elementary schools volunteered to take part in the study, in either the Kids Living Fit program or in the contrast group
Registered nurses used standardized practices to measure participants at baseline, Week 12 and Week 24 for height, weight, BMI-for-age and BMI-for-sex (determined by the Centers for Disease Control and Prevention's online BMI child and teen percentile calculator) and waist circumference
The Kids Living Fit Group met once weekly immediately after school for 12 consecutive weeks
- At Weeks One, Four, Eight and 12, this group had 30 minutes of exercise
- At Weeks Two, Three, Five, Six, Seven, Nine, 10 and 11, the group had one hour of exercise
- At Weeks One, Four, Eight and 12, registered dietitians gave 30-minute nutrition education presentations. Parents were encouraged to attend the nutrition education sessions.
- Participants completed food, activity and satisfaction questionnaires at baseline, Week 12 and Week 24
- The purpose of the diaries was to make participants more aware of food and activity choices; the diaries were not incorporated into any analyses
In the Contrast Group, BMI and waist circumference were measured at baseline and Weeks 12 and 24, following the same procedures as the Intervention Group
The Contrast Group also completed satisfaction questionnaires during the school day
There was no fee to participate in the Contrast Group, whereas the fee for the Intervention Group was $100.

Blinding Used

None.

Intervention

Weekly exercise led by a physical fitness trainer
- At Weeks One, Four, Eight and 12, this group had 30 minutes of exercise
- At Weeks Two, Three, Five, Six, Seven, Nine, 10 and 11, the group had one hour of exercise
- Various types of physical fitness activities were performed, such as aerobic dance, light strength training, stretching, balancing techniques, heart rate monitoring, yoga and relaxation techniques
- Best lifestyle choices were reinforced.
30-minute nutrition education presentations given by registered dietitians at Weeks One, Four, Eight and 12
- Week One discussed best choice selections for lunch
- Week Four introduced the USDA food pyramid and serving sizes
- Week Eight was an age-appropriate interactive portion distortion presentation from NHLBI and US DHHS
- Week 12 focused on making best choices at fast food restaurants and summarized information from the previous three presentations.
Food, activity and satisfaction questionnaires at baseline, Week 12 and Week 24, recording 10 favorite foods and 10 family-favorite foods categorized by choice (best choice, okay choice or choice that should be limited) and by food groups. Participants also specified 10 favorite activities by choice category and whether they were inactive or active. On the satisfaction questionnaire participants categorized level of satisfaction with food choices (very satisfied, satisfied or not satisfied) with food choices, activity choices, family food choices and family activity choices.
Daily diaries at Weeks One, Four, Eight, 12 and 24, recording: Total time of the 10 activities most time spent doing that day, pedometer totals, food intake specifying servings per day by food group and number of fast food meals, and number of best choice lunches.

Statistical Analysis

Pairwise T-tests were used in both the intervention and contrast groups to compare individual participant performance and outcomes at baseline and at 24 weeks.

Data Collection Summary:

Timing of Measurements

Baseline, Week 12 and Week 24.

Dependent Variables

BMI (determined by the Centers for Disease Control and Prevention's online BMI child and teen percentile calculator adjusted for age and sex)
Waist circumference.

Independent Variables

Exercise component
Nutrition education component
Food questionnaires
Activity questionnaires
Daily diaries.

Control Variables

Both groups completed satisfaction questionnaires.

Description of Actual Data Sample:

Initial N

194 students.

Attrition (Final N)

185 students total; 80 in the Intervention Group (48 girls, 32 boys) and 105 in the Contrast Group (45 girls, 60 boys).

Age

Mean age for the Intervention Group was 9.4 years, whereas the mean age for the Contrast Group was 9.2 years.

Ethnicity

62% of the Intervention Group were white; 18% were non-white Hispanic
For the Contrast Group, 83% were white; 22% were non-white Hispanic.

Anthropometrics

Groups were not matched on BMI percentile at baseline
In the Intervention Group, 40% (N=32) were between the fifth to 84th percentile; 27.5% (N=22) were between the 85th to 94th percentile and 33.5% (N=26) were at or above the 95th percentile
In the Contrast Group, 81% (N=85) were between the fifth and 84th percentile; 8% (N=9) were in 85th to 94th percentile and 8% (N=8) were at or above the 95th percentile.

Location

Loudoun County Public Schools, Leesburg, VA.

Summary of Results:

Key Findings

In the Intervention Group, all participants had a decrease in mean BMI percentile scores of 2.3 points, from 76.1 to 73.8 (P<0.01), whereas paired BMI percentile scores increased by 1.5 points (P<0.01) in the Contrast Group
The Intervention Group had a 5% increase in the number of children with a BMI in the normal-weight percentile category, with a corresponding decrease in the at-risk and overweight categories from baseline to Week 12
The Intervention Group had a smaller increase in waist circumference, compared with the Contrast Group from baseline to Week 24 (P<0.02).

Variables	Intervention Group Measures and confidence intervals	Contrast Group Measures and confidence intervals	Statistical Significance of Group Difference
BMI Percentile, Change in Points	-2.3	1.5	P<0.01
Waist Circumference, Increase in Inches	0.42	0.98	P<0.02

Other Findings

At Week 24, participant satisfaction with the intervention was 94%
61% of participants in the Intervention Group said the intervention helped a lot
33% of participants in the Intervention Group said the intervention helped a little
6% of participants in the Intervention Group said the intervention did not help.

Author Conclusion:

Participants in the Kids Living Fit Intervention Group experienced a decrease in BMI percentile scores from baseline to Week 24
After-school programs such as Kids Living Fit can be implemented by school nurses to facilitate healthy lifestyle choices in elementary school children with the goal of decreasing obesity.

Funding Source:

Other:

None mentioned, other than Burger King providing salad coupons for intervention group participants.

Reviewer Comments:

There were many limitations to this study. Those mentioned by the authors are the possibility of selection bias due to the non-randomized design of the intervention; parents may have urged their at-risk for overweight or overweight children to participate in the Intervention Group and children may have been more motivated to comply with the intervention due to parental support.
Another limitation discussed by the authors is regression to the mean, which may be the cause of the change observed among the self-selected participants
The authors stated that Intervention Group participants recorded pedometer totals, however the authors did not discuss when participants were given pedometers or how long they were to be worn (school day, all day, weekdays only, etc)
Food and activity questionnaires were used but authors made no mention of validation of these questionnaires. Also, a description of how waist circumference was measured was not given (where exactly on the child the measurement was taken).
The sample size for this study was small, and no power calculation was given to determine how many participants were needed
Finally, the authors did not report statistical significance (P-value) for many of the measurements to demonstrate change/lack of change between the groups from baseline to Week 24.

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?		???
	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?	???
	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.)	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?	Yes
	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?		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?	No
	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?	???
	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?	Yes
	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?	Yes
	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?		???
	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?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	???
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	???
	7.7.	Were the measurements conducted consistently across groups?	???
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?	???
	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)?	Yes
	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?	???
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?		???
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes