EAL

Pediatrics and Physical Activity

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The objective of this study is to examine the correlates and predictors of adiposity, including several physical activity indicators, among a cohort of Mohawk elementary school children participating in a community based diabetes prevention project.

Inclusion Criteria:

Not Specified

Exclusion Criteria:

Not Specified

Description of Study Protocol:

Measure were taken over 3 weeks at the schools. Body composition was taken by a trained nurse. Measures of height, weight, subscapular and triceps skinfolds as well as hip and waist circumferences were measured. In class children in grades 4-6 completed a questionnaire while children in grades 1-3 completed them at home with their parents. Additionally a one mile (4-6) or half mile (1-3) walk/run was completed.

Data Collection Summary:

Dependent Variable

Body fatness – subscapular skin fold thickness

Independent Variable

Physical activity – categorized (everyday, 4-6, 1-3, no days)
Physical inactivity – 6+ programs/day = excessive, those who watched less were moderate)

Confounders:

Ethnicity (Mohawk)
Gender

Statistical Analyses: Separate analyses were carried out for each gender.

Cross-sectional analyses:

Zero-order correlation coefficients were computes and variables significant at a P .10 were retained for multivariate analyses.
The significance of each independent variable was tested suing stepwise regression while control first for other variables of the same category followed by demographics.

Longitudinal analyses: Same format as cross-sectional. Predictors for the skinfold measures at follow-up were derived while controlling for the baseline skinfold assessment.

Description of Actual Data Sample:

Initial N: 198 Mohawk Students (95 boys, 103 girls)

Age: average age 7.5 (±1.3)at baseline

Summary of Results:

Girls

For girls, not playing outside during the past week, watching excessive television, and being involved in community and summer sports were associated (p<.10) with higher skinfold thickness at both evaluation rounds.
Among girls, being less physically active (R² = .04), watching excessive TV (R² = .14) and summer sports (R² = .03) were associated with increased subscapular skinfold thickness at baseline.
The mean subscapular skinfold thickness among girls who watched excessive TV was 30% higher than among those who watched less TV.
Independent predictors for skinfold thickness CHANGE in girls were baseline skinfold thickness (R² = .67), younger age (R² = .01), watching TV (R² = .01 and higher relative PA (R² = .01).

Boys

Among boys, being involved in summer sports (R² = .09) and not playing outside (R² = .05) were independent correlates of the log of the subscapular skinfold thickness at baseline. The only independent predictor of skinfold thickness change in boys was baseline skinfold thickness (R² = .72).

Author Conclusion:

For cross-sectional analyses, the strongest predictor of skinfold thickness, in girls, was excessive television watching.
Longitudinal analyses showed the strongest predictor of skinfold change was the baseline subscapular skinfold thickness. TV viewing was a weak independent predictor of adiposity change in girls in longitudinal analyses but not for boys.

Overall conclusion:

Baseline skinfold thicknesses predicted follow-up skinfolds. For girls, TV viewing appears to be associated with adiposity.

Funding Source:

Government:

National Health Research & Development Program, Health Canada, Kahnawake Education, Mohawk Council of Kahnawake

Reviewer Comments:

For boys, it appears that physical activity may be have a bigger impact whereas for girls physical inactivity may have a greater impact.

Limitations:

TV viewing – anything less than 6 programs was seen as moderate, they did not include a “low” group. In addition, no validiation was done for the TV viewing measure.

Strength:

both cross-sectional and longitudinal analyses were done.

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)	N/A
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	N/A
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	N/A
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	N/A

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?	N/A
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	N/A
	1.3.	Were the target population and setting specified?	N/A
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?	N/A
	2.2.	Were criteria applied equally to all study groups?	N/A
	2.3.	Were health, demographics, and other characteristics of subjects described?	N/A
	2.4.	Were the subjects/patients a representative sample of the relevant population?	N/A
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)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	N/A
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	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?	N/A
	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%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	N/A
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	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?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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.)	N/A
	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?	N/A
	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?	N/A
	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?	N/A
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	N/A
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	N/A
	7.5.	Was the measurement of effect at an appropriate level of precision?	N/A
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	N/A
	7.7.	Were the measurements conducted consistently across groups?	N/A
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?	N/A
	8.2.	Were correct statistical tests used and assumptions of test not violated?	N/A
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	N/A
	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)?	N/A
	8.6.	Was clinical significance as well as statistical significance reported?	N/A
	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?	N/A
	9.2.	Are biases and study limitations identified and discussed?	N/A
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	N/A
	10.2.	Was the study free from apparent conflict of interest?	N/A