EAL

PWM: Family Influences (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To what extent is obesity in Anglo and Mexican-American children related to maternal:

nutrition knowledge,
feeding practices,
values,
socioeconomic status,
acculturation and
demographic variables.

Inclusion Criteria:

Not described

Exclusion Criteria:

Not described

Description of Study Protocol:

Recruitment

Mother/child pairs recruited from local WIC clinics.

Design

Child anthropometric data gathered. Mother BMI taken.

Information on maternal nutrition knowledge and practices were gathered using surveys translated into English and Spanish.

Maternal nutrition knowledge assessed using a 21 question survey with higher scores indicating greater nutrition knowledge.
Maternal feeding practice questionnaire consisted of eight items with a higher score indicating "pushier" [author's word] feeding practices.
Locus of weight control questionnaire assessed the mother's perception of her control over her own dietary practices.
Infant body habitus scale measured the mother's perception of the ideal baby size and weight.

Blinding

Not mentioned, presumably none.

Statistical Analysis

Logistic and multiple linear regression, descriptive statistics.

Data Collection Summary:

Dependent Variables

Child overweight: subscapular and triceps skinfold thickness, height, weight
Maternal nutrition knowledge
Maternal feeding practices
Maternal locus of weight control
Maternal perception of the ideal infant
Socioeconomic status: measured using an index measuring education and occupation of head of household (higher scores indicate higher SES)

Independent Variables

Obesity defined as BMI Z score >=85th percentile for age (NCHS data). Measured using BMI Z score and Z score for skinfold thickness.

Control Variables

Ethnicity: Anglo versus Mexiacan-American

Description of Actual Data Sample:

Initial N:

189 Mexican-American, 188 Anglo mother and child pairs

Attrition (final N):

Age: 3-5 years

Ethnicity: Anglo and Mexican American

Other relevant demographics:

Mean Maternal BMI: Anglo: 26, Mexican-American: 28.2
Mean Maternal Age: 28 for both groups
Number of mothers in sample married: Anglo: 135, Mexican-American: 115
Average years of education of mother: Anglo: 13.9, Mexican-American: 11.2

Location: Arizona, USA

Summary of Results:

Multivariate Analysis of Risk Factors for Obesity

Multivariate analysis revealed the following risk factors for the two ethnic groups compared.

Mexican American

Anglo American

male child
maternal perception of child's weight status at 9 months
high mother BMI

Family Factors:

lower education for mother and father
unemployed father
lower SES
lower nutrition knoweldge by mother

Feeding Practices:

bottle fed (rather than breast fed)
use of infant feeder or large holed nipple
putting solid food in bottle
use of bottle to comfort child
adult over or under involvement in feeding
number of people feeding the child

high birthweight
maternal perception of child's weight status at 9 months
high mother BMI

Family Factors:

mother unmarried
lack of adult male in household
unemployed father
lower SES
mother external control of body weight

Feeding Practices:

bottle fed (rather than breast fed)
solid food at early age
mother over or under involvement in feeding
putting solid food in bottle
use of bottle to comfort child
number of people feeding the child

Relation of Obesity and Maternal Nutrition Knowledge: Significant correlation for entire sample (-.11 p<.02), but not for either subgroup.

Relation of Obesity and Maternal Feeding Practices: No significant correlations.

Maternal Perception of Control of Own Body Weight: No significant correlation to child obesity.

Mother Ideal Infant Body: Significant correlation only for Anglo group (-.15, p<.02), however scale not described so it is unclear how to interpret this correlation.

Relation of SES and Child Obesity: Significantly correlated for the entire sample (-.19, p<.001), and for Mexican-American children (-.2, p<.02). The lower the SES score, the greater the likelihood of child obesity.

Mothers Acculturation Score (Mexican-American mothers): no significant correlation with child obesity.

Relation of Demographic Variables and Child Obesity

= signficant positive relationship

= significant negative relationship

Blank = no significant relationship

Demographic Factor	Significant Relation to at Least One Measure of Adiposity
	Mexican-American	Anglo
BMI of mother
Age of mother
Mother married
Male child
Birth weight
Amount breast fed
Age when non-milk food introduced
Solids put in bottle or infant feeder
Number of people feeding the child
Sitter feeds the child
Low nutrient density snacks

Mexican-American Mother versus Anglo Mothers

Compared to Anglo mothers, Mexican-American mothers showed:

lower nutrion knowledge
higher involvement in feeding
less internal control over their own weight

Author Conclusion:

The impact of family environment on childhood overweight is of importance.

Since treatment of childhood overweight has not been shown to be effective, emphasis must be placed on prevention of childhood overweight. This means that it is important to identify culturally relevant factors related to childhood overweight, and use this knowledge to guide practice.

Funding Source:

University/Hospital:

University of Arizona

Reviewer Comments:

Strengths:

Comparison of ethnic groups

Weaknesses:

Poor description of sample, how they were recruited, whether any were excluded, etc.
Odds ratios difficult to interpret as no reference group or category was given.

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?		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?	No
	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.)	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.)	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?		No
	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%.)	No
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	No
	4.4.	Were reasons for withdrawals similar across groups?	No
	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?	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.)	No
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	No
	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?	No
	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?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	No
	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?		No
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes