Pediatric Weight Management

Pediatrics and Physical Activity

Citation:

Gordon-Larsen P. Obesity-related knowledge, attitudes, and behaviors in obese and non-obese urban Philadelphia female adolescents. Obesity Research 2001;9(2):112-18

PubMed ID: 11316345
 
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 examine relationships between knowledge, attitudinal and behavioral factors, and obesity and to determine how these factors influence obesity status in west Philadelphia female adolescents.
Inclusion Criteria:
Not Specified
Exclusion Criteria:
Not Specified
Description of Study Protocol:
A matched pair of females (obese and non-obese) was drawn from a larger obesity study. Stature, weight, and triceps skin folds were taken.  Then a questionnaire was administered to elicit information on the behavior, knowledge and attitude of the west Philadelphia adolescents
Data Collection Summary:

Independent Variables: 

  • Obese (BMI and skin fold > 95th percentile) vs. Non-obese (BMI and skin fold >15th percentile)

Dependent Variables:

  • Dietary Intake (3 24-hour recalls collected by personal interview)
  • Physical Activity (7-day Physical Activity Recall)
  • Inactivity (Television viewing recall survey for # of hours in the past week, # of videos and cable TV shows watched, # of hours engaged in playing video games)
  • Maturational Status (Recall of Age of Menarche)

Confounders: 

  • Economic status (sample was economically disadvantaged)
  • Race (99% were African American)
  • Age (11-15)
  • Stature (matched on this criteria)

Statistical Analyses:

Data were analyzed using Wilcoxon matched paired signed rank tests and ANOVA to compare behavioral, attitudinal, and knowledge factors of obese relative to non-obese adolescents.

Description of Actual Data Sample:
32 obese and 32 non-obese matched pairs of African American females from urban Philadelphia. These families were economically at a disadvantage (>84% from low income family, all eligible for free lunch program)
Summary of Results:
Obese females spent significantly less time engaged in light to moderate physical activity (ES=1.22,P > .0008) over a 1-week period and significantly more time engaged in weekly inactivity (p > .04) than did non-obese females.  
Author Conclusion:

Knowledge and attitudinal factors with the exception of ideal body size perception had far less impact on obesity than activity related behavioral factors.

 

This study presents strong findings for the association of obesity and physical activity and inactivity and contributes valuable information regarding the influence of knowledge, attitudes, and behaviors surrounding adolescent obesity.

 

Overall conclusion:

  • Obese adolescents had significantly lower levels of physical activity and higher inactivity than the non-obese adolescents.
  • TV time could be an effect of obesity not a cause, so a causal link can not be assumed.
Funding Source:
University/Hospital: University of Pennsylvania, University of North Carolina
Not-for-profit
0
Reviewer Comments:

Limitations: 

  • Small sample size
  • Use of 7 day PA measure led to ‘floor’ effect (ie-no PA)
  • PA measure only looked at light to moderate PA

Strengths:

  • Included multiple days of Physical activity recall
  • Used multiple forms of inactivity.
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? 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? 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? Yes
  2.2. Were criteria applied equally to all study groups? N/A
  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? Yes
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? Yes
  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%.) 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? 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? Yes
  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? Yes
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? Yes
  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? 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