Pediatrics and Physical Activity
Horn OK, Paradis G, Potvin L, Macaulay AC, Desrosiers S. Correlates and predictors of adiposity among Mohawk children. Preventive Medicine 2001; 33: 274-281.PubMed ID: 11570831
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.
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.
- Body fatness – subscapular skin fold thickness
- Physical activity – categorized (everyday, 4-6, 1-3, no days)
- Physical inactivity – 6+ programs/day = excessive, those who watched less were moderate)
- Ethnicity (Mohawk)
Statistical Analyses: Separate analyses were carried out for each gender.
- 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.
Initial N: 198 Mohawk Students (95 boys, 103 girls)
Age: average age 7.5 (±1.3)at baseline
- 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).
- 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).
- 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.
Baseline skinfold thicknesses predicted follow-up skinfolds. For girls, TV viewing appears to be associated with adiposity.
|Government:||National Health Research & Development Program, Health Canada, Kahnawake Education, Mohawk Council of Kahnawake|
For boys, it appears that physical activity may be have a bigger impact whereas for girls physical inactivity may have a greater impact.
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.
both cross-sectional and longitudinal analyses were done.
Quality Criteria Checklist: Primary Research
|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|
|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|