PWM: Physical Activity and Inactivity of Youth (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To describe the TV/video viewing habits of a multiethnic, low-income preschool population of children and to determine whether TV/video viewing is related to their adiposity.

Inclusion Criteria:
Not specified.
Exclusion Criteria:
Not specified.
Description of Study Protocol:

Supplemental nutrition program for women, infants, and children (WIC) was self-administered, one child per family was included. These surveys were completed annually for 2 years. (1999, 2000). Children and parents were visiting the clinic every 2 months for the nutrition counseling and to receive food vouchers.  Height and weight was measured every 6 months by the WIC staff (frequently on the same day as the survey was completed).

Statistical Analyses:

ANOVA examined differences in TV viewing time by race/ethnicity and parental educational attainment.

Chi square tests examined the differences in the percentages of children viewing any TV and the percentages of children viewing >2 hours of TV per day by race/ethnicity

Multiple logistic regression was used to identify independent predictors of children with a BMI >85th percentile.  

T-test was used to examine the differences in Tv viewing time of children with and without TV’s in their bedroom.

Data Collection Summary:

Dependent Variables

  • Overweight (BMI > 85th percentile)

Independent Variables

  • Overweight Status: “Overweight group” (BMI > 95th percentile) vs. “At risk for overweight” (>85th percentile)
  • Time spent watching TV (parent self-report of “usual” Tv viewing during week, Saturday, and Sunday)
    • 2 groups – “usually” and “not usually”
  • TV in the child’s bedroom (self-report)

Confounders

  • Race/ethnicity
  • Parental educational attainment
  • Income Level (low)
Description of Actual Data Sample:

2761 parents with children ages 1-5 from the New York State agencies of the WIC (low-income).

The sample was racially and geographically balanced sample.

(34.5% white, 33.4% Hispanics, 22.7% blacks)

Summary of Results:

Hispanics had higher prevalence of obesity than whites or blacks. Black children, however, watched more TV than whites or Hispanics.

Percentage of children with BMI 85th percentile decreased with higher parental educational attainment x² = 5.6, (df = 1); P<.02

In the Logistical regression analyses, the prevalence of overweight children was significantly related to the amount of time that children spent watching TV p<.03, after adjustment for child age, parental education, child sex, and race/ethnicity

The odds ratio for the prevalence of children with a BMI>85th percentile associated with each additional hour per day that the children watched TV was 1.06.

Children with a TV in their room spent an additional 4.6 hours per week watching TV (t = 7.8, p = .0001).

The prevalence of children with BMI >85th percentile was higher among children with TV in their bedroom compared with those without x² = 11; p = .001.

In the logistical regression, children with Tv in their room  were significantly more likely to have a BMI > 85th percentile (OR: 1.31; CI: 1.01-1.69; p<.05), even after controlling for age, race, sex, maternal education, and maternal BMI.

More black and Hispanic children had TV’s in their bedrooms than white children.

Author Conclusion:

Time spent viewing TV was significantly related to the prevalence of child overweight.

TV’s in the child’s bedroom was more strongly associated with increased risk of child overweight than the child’s weekly TV viewing hours.

Overall conclusion:

There is a positive association between TV viewing and risk of overweight and it extends to an even younger age group (1-5). 

Funding Source:
University/Hospital: Bassett Healthcare, Columbia University
Reviewer Comments:

Limitations:

TV viewing was reported not observed so there could be some discrepancy in the actual time spent watching TV.
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? No
  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? 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? Yes
  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? No
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) No
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) No
  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.) Yes
  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? No
  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? Yes
  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? No
  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? 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