Pediatric Weight Management

Pediatrics and Physical Activity

Citation:

Ward DS, Trost SG, Felton G, Saunders R, Parsons MA, Dowda M, Pate RR. Physical activity and physical fitness in African-american girls with and without obesity. Obesity Research 1997; 5(6):572-577.

PubMed ID: 9449142
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  • To compare the physical activity behavior of African-American girls with and without obesity residing in rural South Carolina.
  • To examine the relationship between obesity and physical fitness, cardio-respiratory fitness and upper body strength were measured and compared.
Inclusion Criteria:
Not specified
Exclusion Criteria:
Not specified
Description of Study Protocol:
  • Anthropometric measures as well as PWC 170 were conducted in the lab.
  • The PDPAR was completed on 3 consecutive days.
Data Collection Summary:

Independent Variable: 

  • Obese vs. non-Obese (BMI or skinfold thickness > 85th percentile)

Dependent Variable: 

  • Physical activity (PDPAR – 30 minutes and intensity for that time)
  • Physical Fitness (PWC170)
  • Maximal shoulder extension and elbow flexion (isometric cable tension)
  • Height/weight = BMI
  • Skin fold (calf, triceps)

Confounders: 

  • Age (5th grade)
  • Gender (female)
  • SES (mostly low – eligible for free lunch)
  • Ethnicity - African American

Statistical Analyses: 

  • Differences between girls with and without Obesity on physical activity and physical fitness were tested using Student T-tests. 
  • Associations between PA variables and body composition were assessed using spearman rank order correlation coefficients.
Description of Actual Data Sample:

N: 150 African –American female, 54 obese, 94 non-obese.

Age: 5th graders

Location: South Carolina, USA

Summary of Results:
  • Girls with obesity reported significantly lower participation in VPA (p < .01)
    and MVPA (p < .01)
  • Participation in VPA and MVPA was inversely associated with BMI (r=-.17 and r=-.19, respectively) and triceps skinfold measurements (r=-.19 and r=-.22, respectively).
  • Correlations between the physical activity variables and calf skinfold measurements were in the expected direction, but were of marginal statistical significance (p< .10)
Author Conclusion:
  • The results indicate that African American girls classified as obese participate in significantly fewer physical activities and are less physically fit than their non –obese counterparts.
  • PA behavior was inversely associated with several measures of adiposity.
  • Low levels of physical activity (or inactivity) may be important contributing factors in the development and or maintenance of obesity in young African American girls..

Overall conclusion:

Lack of physical activity is an important factor in the development and/or maintenance of obesity.

Funding Source:
Industry:
Abbott Laboratories
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:

Limitations:

  • Cross-sectional – no ability to determine cause and effect.
  • Did not measure dietary behavior therefore that was not controlled for.

Strength: although they used a self-report measure of PA it is a well-established measure. (PDPAR)

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