HD: Food Security (2011)

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

To examine the characteristics associated with the likelihood of experiencing persistent and transitional food insecurity among adults and how the patterns of adult food insecurity can influence toddler cognitive and motor development, weight and health status.

Inclusion Criteria:
  • Data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), collected by the National Center for Education Statistics (NCES), was analyzed for this study
  • This is a longitudinal study of children born in 2001 with follow-up at two years of age, four years of age and entry to Kindergarten
  • The information from 2001 and 2003 were used in this analysis.
Exclusion Criteria:

Participants that were missing data for the outcomes studies or food insecurity variable or that did not participate in the two-year-old follow-up were excluded.

Description of Study Protocol:
  • Recruitment: Specifics of recruitment for the Early Childhood Longitudinal Study-Birth Cohort were not described in this analysis of data
  • Design: Review of longitudinal cohort study relating to data at birth (zero to nine months) and toddler (two years) ages
  • Blinding used: Includes study analysts looking at data from an existing study rather than collecting the data
  • Statistical analysis: Logistic regression models, ordinary least square regression models and sensitivity analyses.
Data Collection Summary:

Timing of Measurements

  • First Wave: Birth to nine months of age in 2001
  • Second Wave: Two-year-old toddlers in 2003.

Dependent Variables

  • Child cognitive and motor development measured using Bayley Short Form-Research Edition (BSF-R) Mental Scale and Motor Skills Scale
  • Child Health Status per mother's self-report.

Independent Variables

 Adult food insecurity calculated from 18 item USDA scale.

Control Variables

  • Child characteristics such as age (in months) at time of assessment, race or ethnicity and birth order number
  • Mother's characteristics such as age, education, US-born, employment status and marital status
  • Household characteristics, such as income, home ownership, number in household, number of times household eats dinner together per week, geographic region and size of city, town or rural area.
Description of Actual Data Sample:
  • Initial N: 8,950 participant data from First and Second Waves
  • Attrition (final N): 7,900
  • Age: Children were aged from birth to two years of age. Mothers' ages were assessed as less than 20, 20 to 29 or 30 or older.
  • Ethnicity: See results
  • Other relevant demographics and anthropometrics: See results
  • Location: United States.
Summary of Results:

Key Findings

Toddlers who lived in households where mothers experienced temporary or persistent food insecurity had lower cognitive scores and worse health status than food-secure families.

Table of Regression Models Showing the Influence of Adult Food Insecurity Patterns on Developmental Outcomes at 24 Months

  Cognitive Scores Motor Scores Weight for Age Z-Scores Health Status
Both Waves
-0.87±0.81
-0.58±0.40
-0.05±0.10 
-0.06±0.06
Wave One Only
0.41±0.54
0.10±0.29
0.07±0.08
0.00±0.05
Wave Two Only
-1.50±0.69 (P<0.05)
0.05±0.35
-0.01±0.09
-0.17±0.07 (P<0.05)
Author Conclusion:
  • Adults experiencing food insecurity were more economically disadvantaged
  • Toddlers appear to be buffered from the negative impact of food insecurity of the adult
  • Temporary food insecurity appears to have a larger impact on toddlers than persistent food insecurity.
Funding Source:
Government: USDA Research Innovation and Development Grants
Reviewer Comments:

Thorough analysis of data and discussion of findings.

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) 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? 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? 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? Yes
  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? 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")? Yes
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? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? Yes
5. Was blinding used to prevent introduction of bias? Yes
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  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? Yes
  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? No
  6.6. Were extra or unplanned treatments described? No
  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? 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? 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? 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