EAL

Child Nutrition and Environment

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the association between a hazardous neighborhood context and physical activity in children.

Inclusion Criteria:

Fourth Grade students enrolled in eight northern California elementary schools.

Exclusion Criteria:

None listed.

Description of Study Protocol:

Recruitment

Fourth-grade students enrolled in eight northern California elementary schools were eligible to participate
A passive-consent procedure.

Design

Cross-sectional.

Intervention

No intervention
Associations among variables.

Statistical Analysis

One-way analysis of variance was conducted to examine differences by child acculturation, SES level and ethnicity.
Spearman correlations were determined among study variables
To examine whether school effects masked an association between neighborhood hazards and physical activity, the following analyses were performed
- First, one-way analysis of variance and chi-square tests were conducted to examine differences in means for variables of interest by school. Intra-class correlations with physical activity were investigated using mixed models with compound symmetry as the covariance structure. All intra-class correlations were close to zer, thus the original Spearman correlations were reported.
- Second, a test was conducted to determine homogeneity between schools and the correlations between neighborhood hazards and physical activity, physical fitness and BMI.

Data Collection Summary:

Timing of Measurements

All parent and child assessments were completed within the same two-month period.

Dependent Variables

Children completed questionnaires during a regular class period. The survey was read aloud to the entire class and took approximately 45 minutes to complete. Surveys were prepared with facing pages written in English and Spanish or English and Vietnamese. Children were given the option to have the survey read aloud to them in English, Spanish or Vietnamese; 88% completed in English, 9% in Spanish and 3% in Vietnamese.
All physical measures were obtained at stations set up in the classroom or at a nearby outdoor area
All parent interviews were conducted on the telephone. Parent interviews were conducted in English (33.6%), Spanish (43.9%) and Vietnamese (22.5%).
Socio-economic status: Parent self-reported education levels and occupations. Occupation was chosen as an indicator of SES instead of education level or a combination of the two. This was due to the high percentage of immigrants in the sample who may have been educated in another country but whose income in the United States may not reflect their education level. Parent occupation was coded into the seven Hollingshead categories and then dichotomized into lower (one to four) and higher (five to nine) SES levels, based on the mid-point of the scale.
Child acculturation: Determined based on language preference for English or another language when at home, with friends and when watching television. These items were adapted from the language, using sub-scale of the Bidimensional Acculturation Scale for Hispanics. English usage and other language usage items were averaged separately and mid-point cut-off scores were used to dichotomize these measures into high and low categories. Four acculturation categories, as described by Cuellar et al, were determined based on the following combinations:
- Traditional (high use of another language or low English use)
- Marginalized (low use of another language or low English use)
- Assimilated (high English use or low use of another language)
- Bi-cultural (high use of another language or high English use).
Neighborhood hazards: Children's perceived neighborhood hazards were assessed with eight self-reported items based on a three-point Likert-type scale: 1 indicated "not a problem," 2 indicated "a little problem," 3 indicated "a big problem." This scale was adapted from the Hazards Scale developed by Aneshensel and Sucoff. The eight items included traffic, trash and litter, crime, too much noise, gangs, lack of access to parks, prejudice and drugs. All eight items were summed for a total score with a possible range of eight to 24, with a higher score indicating the perception of more neighborhood hazards. The internal consistency of this scale was found to be alpha =0.76.
Self-reported physical activity: Modified version of the Self-Administered Physical Activity Checklist (SAPAC). This was modified to include only after school activities, added two more common activities (for a total of 23) and simplified the response to be a forced choice of "none," "less than 10 minutes," or "more than 10 minutes." Children reported their previous day's physical activity on two different days and these two reports were averaged.
Physical fitness: Maximal multi-stage 20-minute shuttle run test of physical fitness was used to assess cardiorespiratory fitness
Height, weight and BMI: Standing height was measured using a portable direct-reading stadiometer. Weight was determined using digital scales with the subjects wearing light indoor clothing without shoes or coats. BMI was calculated.

Independent Variables

None.

Control Variables

None listed.

Description of Actual Data Sample:

Initial N

Total enrolled Fourth Grade students in the eight schools: 845.

Attrition (Final N)

796 (94%) participated
12 parents refused to allow their children to participate and other eligible children not included were absent or unavailable on assessment days
518 parents or guardians completed the interviews.

Age

9.0±0.37 years.

Ethnicity

Children

Latino: 387 (49.9%)
Asian: 255 (32.9%)
Pacific Islander/Filipino: 63 (8.1%)
European American: 43 (5.5%)
African-American: 28 (3.6%).

Parents

Mexican: 272 (54.2%)
Vietnamese: 108 (21.5%)
Filipino: 39 (7.8%)
European American: 27 (5.4%)
Central American: 15 (3.0%)
African-American: 10 (2.0%)
Other: 29 (5.8%).

Other Relevant Demographics

Children

Male: 398 (50.0%)
Female: 398 (50.0%).

Parent

Male: 39 (7.6%)
Female: 473 (92.4%).

Anthropometrics

Not given.

Location

Northern California.

Summary of Results:

Key Findings

There were no significant differences between boys and girls for the perception of neighborhood hazards, self-reported physical activity, height, weight or BMI
There were no significant differences in neighborhood hazards, reported physical activity or physical fitness by child acculturation level
There were no significant differences in physical fitness or reported physical activity by SES level, but there were significant differences in neighborhood hazards by this measure (P=0.04). Children of lower SES reported more neighborhood hazards (mean ±SD, 13.51±3.83) than children of higher SES (mean ±SD, 12.73±3.48).
There were significant ethnic differences for reported physical activity levels (P<0.001) and physical fitness (P=0.01). Latinos reported significantly higher rates of physical activity than Asians (mean ±SD, 8.67±4.61 and 7.19±4.39, respectively) and Latinos ran significantly more total laps than Asians (mean ±SD, 17.21±10.65 laps and 14.45±7.36 laps, respectively).
The perception of more neighborhood hazards was positively correlated with reported physical activity (R²=0.13; P<.001).
There was a slight positive association between self-reported physical activity and BMI (R²=0.09; P<0.05), but the amount of body fat, as measured by BMI, was significantly negatively associated with physical fitness (R²=-0.36; P<.001)
Neighborhood hazards and SES were negatively correlated (R=-0.13; P=0.01) thus all further correlations were conducted separately by lower and higher SES levels
For both SES levels, physical fitness and BMI were inversely correlated (R²=-0.36 for both; P<0.001), as expected
No significant association between neighborhood hazards and reported physical activity or neighborhood hazards and physical fitness for the lower SES group
A significant but low negative correlation was found for neighborhood hazards and BMI for children of lower SES (R²=-0.13; P<0.05). A higher BMI was associated with the perception of fewer neighborhood hazards.
For children of higher SES, the perception of more neighborhood hazards was associated with more reported physical activity (R²=0.18; P<0.001), not with physical fitness or BMI.

Other Findings

Differences in physical fitness existed between the sexes (P<0.001): Boys ran more laps than girls (mean ±SD, 17.61±11.20 laps and 14.66±7.58 laps, respectively)
There were no significant differences by school for perception of neighborhood hazards, self-reported physical activity or physical fitness
School differences were found for ethnicity (P<0.001), SES level (P<0.001) and BMI (P=0.01)
No significant heterogeneity between schools (P>0.05 for all tests).

Author Conclusion:

Limitations, as cited by the investigators
- The acculturation process is more complex than what language use can represent. However, measurement of acculturation based on language has become a common short-hand method that typically accounts for more than half the variance of acculturation measures.
- Measure of neighborhood hazards may have lacked sensitivity because it did not directly assess the degree to which children perceived that the hazard was a barrier to their engaging in physical activity. Additionally, the measure did not assess perceived fear of the hazard. Rather, participants rated the degree to which each potential hazard was a problem.
- The neighborhood hazards scale consisted of only eight potential barriers to physical activity, whereas other potential barriers may exist
- Parents' perceptions of neighborhood hazards may affect the regulation of their children's opportunities for physical activity
- Use of self-reported physical activity.
This study provides no evidence to support the common assertion that children from neighborhoods of lower SES do not engage in physical activity or are any less physical fit because of neighborhood dangers such as crime or gangs
The investigators suggested that future studies in this area examine other potential barriers to physical activity for lower-income children by including assessments of sedentary behavior, parental fear of violence, parental regulation of children's leisure activities and the cost and quality of available locations for physical activity and organized sports.

Funding Source:

Government:

National Cancer Institute R01 CA68082

Reviewer Comments:

Tables One and Two differ with regards to the ethnicity classification of the child and the parent. This difference is due to the fact the school district data provided pan-ethnic labels for all children, such as Latino, that combined several specific ethnic groups within one larger grouping. Parents reported their own sex and specific ethnic label. The parents were interviewed, so it is unclear why the investigators did not ask the parent for the child's specific ethnicity.

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?		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?	???
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)	Yes
	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%.)	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?		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?	Yes
	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?	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?	N/A
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