EAL

NGHC: Childhood Nutrition and Lifestyle Factors (2013)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the impact of the Pathways intervention on psychosocial variables related to physical activity and diet in American Indian children.

Inclusion Criteria:

American Indian children in 41 schools located in Arizona, New Mexico and South Dakota
Schools were located on seven Indian reservations and included public, parochial, Bureau of Indian Affairs and tribal contract schools
Represented tribes included San Carlos Apache, White Mountain Apache, Oglala Lakota, Sicangu Lakota, Navajo, Gila River and Tohono O'odham
Informed consent was obtained from parents of students.

Exclusion Criteria:

Not described.

Description of Study Protocol:

Recruitment

Schools were recruited within four field centers that were staffed by local residents and affiliated with Johns Hopkins University, the University of Arizona, the University of Minnesota or the University of New Mexico
The University of North Carolina at Chapel Hill served as the coordinating center.

Design

Randomized controlled trial.

Intervention

Multi-component Pathways intervention or control condition
Pathways intervention promoted a healthful lifestyle by positively influencing three types of interacting factors (personal, behavioral and environmental) and combined constructs from Social Learning Theory and cultural concepts that included American Indian customs and practices
The Pathways intervention had four major components:
- Food service intervention, which modified foods served in the school cafeteria
- Physical education, which increased physical activity at school
- Classroom curriculum that focused on knowledge and practices related to healthy eating and lifestyle habits
- Family component aimed at involving parents of children participating in the program to create a positive and supportive environment for modifying dietary practices and physical activity.

Statistical Analysis

Mean scores for each scale were reported after setting each item on the scale to range from zero to 1.0, with 1.0 being the most healthy answer and 0 being the least healthy answer
If a child answered every questions in the scale with the most healthy answer the mean score would be 1.0 and if they responded with the least healthy answer to each question on a scale their mean score would be zero
One exception to this system was the question on perceived healthy body size, it was scored between one and eight
Low scores indicated a very thin body size, high score indicated an obese body size and scores toward the middle of the range were considered most desirable
Data were analyzed using the Statistical Analysis System, Version 6.12 (PROC MIXED)
To determine whether the associations between treatment and knowledge, attitudes and behavior (KAB) measures were modified by gender or weight status, we tested gender-treatment and weight status-treatment interaction terms in separate models using the scores from the fifth grade follow-up as the outcomes
To test for an interaction between gender and treatment a gender-treatment interaction as a fixed effect and an interaction between gender and school nested within field was added
To test the interaction between weight status and treatment a weight status-treatment interaction was added as a fixed effect and an interaction between weight status and school nested within field center x treatment condition was added.

Data Collection Summary:

Timing of Measurements

A curriculum knowledge seven-item scale measured nutrition and physical activity knowledge and concepts introduced in the first year of the Pathways curriculum and reinforced in subsequent years.
Knowledge, attitudes and behavior questionnaire (KAB) was completed at baseline and re-administered to the Pathways cohort in the spring of the third, fourth and fifth grades.

Dependent Variables

Psychosocial variables related to physical activity and diet measured by a Knowledge, Attitudes and Behavior questionnaire (KAB). The scales on the KAB questionnaire were based on constructs from social learning theory.
Food self-efficacy measured children's self-efficacy to choose foods lower in fat and sugar using a four-point ordinal response set (ie, I know I can, I think I can, I'm not sure I can and I don't think I can)
Food choice intentions scales consisted of eight items in a paired choice format in which students were asked which food they would choose in different situations
Another six-item scale that identified which food has more fat was administered
A three-item self-efficacy physical activity scale measured children's confidence to participate in physical activity and followed the four-point ordinal response set of the food self-efficacy scale
Physical activity was measured by a 77-item scale with a list of activities that were recalled in specific time frames
An attempted weight loss scale consisted of six dichotomous items assessing attempted weight loss
Gender specific drawings were used to ascertain perceived healthy body sizes
Height and weight were measured using a standard procedure by trained and certified data collectors with children wearing light-weight clothing and without shoes
Body weight categories were determined using age and gender-specific percentile cutoffs for BMI from the growth curves from the Centers for Disease Control and Prevention. Children with a BMI at or above the 85th percentile were classified as overweight.

Independent Variables

Multicomponent Pathways intervention or control condition
Pathways intervention promoted a healthful lifestyle by positively influencing three types of interacting factors (personal, behavioral and environmental) and combined constructs from Social Learning Theory and cultural concepts that included American Indian customs and practices
The Pathways intervention had four major components:
- Food service intervention, which modified foods served in the school cafeteria
- Physical education component, which increased physical activity at school
- Classroom curriculum that focused on knowledge and practices related to healthy eating and lifestyle habits
- Family component aimed at involving parents of children participating in the program to create a positive and supportive environment for modifying dietary practices and physical activity.

Description of Actual Data Sample:

Initial N: 1,706 children
Attrition (final N): 1,447 total (755 boys and 692 girls)
Age: Children from third, fourth and fifth grade
Anthropometrics: Significant differences between groups at baseline in terms of food self-efficacy for girls (P=0.020)
Location:
- South Dakota
- New Mexico
- Arizona.

Summary of Results:

Key Findings

Knowledge of nutrition and physical activity messages increased in both boys and girls in the intervention group compared to controls; however, knowledge of which foods contained more fat did not increase consistently
Compared to controls, self-efficacy to be physically active increased among girls in intervention schools but not among boys, whereas self-efficacy to make more healthy food choices did not increase more than in controls in either gender
In the intervention group, compared to controls, healthy food intentions and participation in physically active behaviors increased in both boys and girls
Perception of healthy body size and weight loss attempts did not differ in the intervention and control groups.

Author Conclusion:

The Pathways study was able to produce changes in several psychosocial variables related to diet and physical activity but did not change the primary outcome of percentage body fat. Future studies with more intense and more broadly reaching interventions may be needed to change behaviors in children sufficiently to impact physiologic measures of good health.

Funding Source:

Government:

National Heart, Lung and Blood Institute

Reviewer Comments:

Significant differences between groups at baseline in terms of food self-efficacy for girls (P=0.020)
This study shares the limitations common to studies that use data from self-reports
The amount of bias or social desirability associated with a school-based intervention is unknown but could be substantial. This bias would not be likely to affect measures of knowledge but could impact all other self-report measures described here. Furthermore, there is also a need for better instruments to measure psychosocial variables.

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)	Yes
	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)	Yes

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?	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?	Yes
3.	Were study groups comparable?		???
	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?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	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?	Yes
	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?	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?	No
	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.)	No
	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?	Yes
	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?	Yes
	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?	Yes
	6.6.	Were extra or unplanned treatments described?	Yes
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	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?	Yes
	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?		No
	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?	No
	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)?	No
	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