EAL

PWM: Physical Activity and Inactivity of Youth (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate the prevalence of pediatric overweight and associated behavioral factors in a Native Canadian community with high rates of adult obesity and type 2 diabetes mellitus.

Inclusion Criteria:

Residents of Sandy Lake who volunteered to participate in this study.
Overweight: BMI at or above the 85th percentile for age and sex-specific reference data from the 3rd NHANES.

Exclusion Criteria:

Medical history of cardiovascular, respiratory or severe musculoskeletal disease and an unwillingness to perform the test for VO₂ max.

Description of Study Protocol:

The analysis of the prevalence of overweight in this article are based on the subsample of 445 children and adolescents who were aged two to 19 years at the time of the survey and for whom height and weight data were available.

Analyses of the factors associated with overweight were based on the subsample of 242 subjects who were aged 10 to 19 years at the time of the survey.

Data Collection Summary:

Dependent

Overweight (BMI based on measured height and weight following standardized protocol).

Independent

Fitness level (VO₂ max adjusted for lean body mass)
Television viewing analyzed as a three-categorical variable (questionnaire)
Body image concepts (questionnaire)
Dietary intake: Energy intake, fat, protein, carbohydrate intake expressed as percentage of energy and fiber (expressed as g/MJ; 24-hour recall).
Vegetables, junk foods, wild foods, breakfast foods, lunch foods, tea foods, bread foods (FFQ scales as quartiles).

Control Variables

Gender
Age.

Statistical Analysis

Multiple logistic regression.

Description of Actual Data Sample:

Original Sample

Not specified.

Withdrawals/Drop-Outs

Due to incomplete data.

Final Sample

445 Native Canadian children and adolescents. Subpopulation of 242 Native Canadian adolescents (94 boys, 148 girls) age 10 to 19 years.

Location

Sandy Lake First Nation, central Canada, remote First Nation community in Canada.

Race/Ethnicity

Isolated Oji-Cree community in northern Ontario.

SES

Not specified.

Age

Ages two to 19.

Summary of Results:

BMI in subjects ages 10 to 19 years was strongly correlated with body fat percentage determined from bioelectrical impedance analysis and waist circumference.

TV Viewing

In the subset aged 10 to 19 years, five or more hours of television viewing per day was associated with a significantly higher risk of overweight than was two or fewer hours per day(OR: 2.52, 1.06-5.98).

Fitness

Subjects in the third and fourth quartiles of fitness had a substantially lower risk of overweight than did those in the first quartile.

Diet Intake

Fiber consumption on the previous day was associated with a decreased risk of overweight (OR: 0.69, 0.47-0.99). For each 0.77 g/MJ increase in fiber consumption, there was a 1.4-fold decrease in risk.
Overweight did not appear to be related to the consumption of any other macronutrient (total energy, protein, fat, carbohydrate, starch, simple sugar) during the previous 24 hours.
There was a significant inverse association between consumption of junk foods (potato chips or French fries, chocolate or candy, cookies or cake, soda, processed luncheon meat and canned fruit) over the previous three months and overweight, although the pattern of association was not clear.

Author Conclusion:

The authors concluded that potentially modifiable factors, including fitness level, body image concepts and fiber intake, were associated with overweight in subjects aged 10 to 19 years.

Funding Source:

Government:

NIH, Ontario Ministry of Health, Health Canada

Reviewer Comments:

Limitations

Cross-sectional nature of the study.

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?	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)	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?	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?		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?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		N/A
	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?		No
	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?	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?	N/A
	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?	No
	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?	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?	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