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AWM: Nutrition Education (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To assess older Americans' ability to use and interpret food labels, and to determine whether label use has the potential to decrease dietary risk factors for disease.
Inclusion Criteria:
Subjects aged 51 years and older who provided 2 non-consecutive 1-day food intake recalls and completed the DHKS survey.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:

Recruitment

Original recruitment strategies from CSFII and DHKS.

Design

Cross-Sectional Analysis.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Data from CSFII 1994-1996 and DHKS used.

Statistical Analysis

Descriptive statistics used to illustrate demographic, social, and economic characteristics.  Low income Americans were oversampled so a weighting variable was used to correct.  To determine whether characteristics of label use were related to sex or age, a weighted ANOVA was used, least significant difference post hoc test for pairwise difference was unweighted.  A correlations matrix was completed using weighted Pearson correlation coefficients and unweighted p-values, including total fat intake as a percent of total energy, dietary and health indices, and food label indices.

Data Collection Summary:

Timing of Measurements

Cross-sectional analysis of CSFII and DHKS data.  CSFII used in-person interviews to conduct 2 non-consecutive 1-day food intake recalls as well as obtain demographic, social and economic data.  DHKS was a follow-up telephone survey.

Dependent Variables

  • Index 1:  Dietary Fat Intake measured through recalls
  • Index 2:  Knowledge of Fat Content of Food measured through 15 questions
  • Index 3:  Use of Reduced Fat Foods measured through 9 questions
  • Index 4:  Use of Added Fat measured through 9 questions
  • Index 5:  Ability to Interpret Food Labels measured through 5 questions
  • Index 6:  Food Label Understanding measured through 7 questions
  • Index 7:  Use of Food Labels measured through 23 questions
  • Index 8:  Presence of Heart-Related Problems measured through absence or presence
  • Index 9:  Self-Reported Health Status measured through 1 question

Independent Variables

  • Demographic, social and economic statistics included sex, region of US, urbanization, household size, marital status, education and income

Control Variables

 

Description of Actual Data Sample:

Initial N: 2846 respondents, 44% male

Attrition (final N):  See above

Age:  Age 51 - 60:  1017 (40%), age 61 - 70:  994 (32%), age 71 - 80:  593 (20%), and age 81+: 242 (8%) 

Ethnicity:  Not described 

Other relevant demographics:

Anthropometrics (e.g., were groups same or different on important measures)

Location:  United States 

 

Summary of Results:

Other Findings

Use of food labels was highest among men 71 - 80 and women 61 - 70, and lowest among men and women over 81 years (p = 0.01 for men, p = 0.002 for women). 

Understanding and use of food labels was lower among older age groups while heart-related health problems increased (p < 0.01).

Use of food labels and percent energy intake from fat were inversely related for all age groups (P < 0.01).

Use of low-fat food products was correlated positively with all 3 label indices:  Use of Food Labels (p < 0.01 for all groups), Food Label Understanding for men and women of all ages (p < 0.01 except women 81+ p < 0.05), and Ability to Interpret Food Labels for men and women 51 - 80 (p < 0.01) and women 81+ (p < 0.05).

Author Conclusion:
The results of this study indicate that older Americans would benefit from education interventions on food label use and interpretation.  Individuals who may be at risk for developing heart problems as well as those already dealing with such chronic health issues, particularly older adults, may benefit from food label education to prevent or help manage heart disease and other nutrition-mediated chronic health problems.
Funding Source:
University/Hospital: Iowa State University
Reviewer Comments:
Large sample size.  Corrected for oversampling.
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? 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? 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.) 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? N/A
  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? N/A
  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? 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? 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