HD: Food Security (2011)

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

To test the feasibility of the Rolling Store, an innovative food delivery intervention, along with a nutrition education program to increase the consumption of healthy foods to prevent weight gain in African American women.

Inclusion Criteria:
  • African American women
  • 18 years of age or older 
  • Body Mass Index (BMI) 25 to 40kg/m2
  • Willingness to participate
  • Able to give informed consent
  • Willingness to make weekly or monthly visits to the study site for six months.
Exclusion Criteria:
  • Women with BMI higher than 40kg/m2
  • Recent or significant underlying diseases such as heart disease, stoke and cancer (other than melanoma skin cancer), medication that could interfere with the study outcomes (e.g., beta blockers for hypertension, all diabetes medications, all lipid-lowering agents) or conditions in which dietary modification was contraindicated (e.g., patients on medically supervised diets)
  • Women unable or unwilling to give informed consent
  • Unable or unwilling to regularly participate for the entire study period
  • Unable to communicate with study staff
  • Currently participating in a dietary or lifestyle modification program
  • Likely to move away from the study area during the study
  • Planning to become pregnant during the study period.
Description of Study Protocol:

Recruitment

Personal communication, posters and fliers were used to recruit participants. 

Design

  • 40 eligible African American women were enrolled in the study and randomized to intervention (20) or control (20) groups
  • The study required at least one monthly contact with participants in the control group and at least 24 contacts with those in the treatment group
  • The peer educator and Rolling Store operator were trained at the Pennington Biomedical Research Center (PBRC):
    • Peer educator received two days of specific and intensive training in study protocol, motivational interviewing technique, behavioral modification technique and basic dietary assessment
    • Rolling Store operator received one day of training in study protocol
  • All participants received calculators, water bottles and duffel bags as incentives for participating in the study
  • At the end of six months in the study, all participants received a cash stipend of $75
  • Study participants were supervised by the principal investigator of the study
  • A trained peer educator and Rolling Store operator implemented the study protocol at a local community center
  • All measurements were conducted by the peer educator at the community center
  • At baseline:
    • Participants were asked to provide demographic, socioeconomic and health information 
    • Dietary assessment was conducted by using PBRC Food Frequency Questionnaire
  • At six months, dietary assessment was conducted by using PBRC Food Frequency Questionnaire
  • Participants were asked to reports all foods eaten during the previous 24 hours
    • Food models and measuring guides were used to facilitate the estimation of portion size
    • Conducted by the peer educator using face to face interviews
    • Dietary recall data were analyzed at the Delta Nutrition Intervention Research Initiative Dietary Coding Center at PBRC by their Food Diary Program
  • Participants were asked to respond to a physical activity questionnaire for safety reason before beginning physical activity
  • At baseline and monthly for six months:
    • Anthropometric assessments consisted of measurements of height, weight and waist circumference
    • Blood pressure was measured
  • Participants were asked to complete two quality-of-life and health questionnaires, at baseline and at the end of study, using the Impact of Weight on Quality of Life instrument.

Intervention 

  • The control group met with the peer educator each month for six months to measure blood pressure (BP) and weight. At that time, nutrition and physical activity information was given to each participant in the control group to take home and read.
  • In a classroom setting, the peer educator taught the same nutrition and physical activity lessons  to the intervention group that was given to the control group. Cooking demonstrations on how to prepare healthier meals were also included.
  • Participants were provided fresh fruits and vegetables each week for 24 weeks from the Rolling Store as well as recipes for healthy preparation techniques
    • The Rolling Store was a truck with a detachable camper shell with banners reading "Rolling with Healthy Choices"
    • The Rolling Store was parked outside the community center from 2:00 P.M. to 6:00 P.M. on the same day of each week
    • Participants in the intervention group received nine to 14 choices of fruits and vegetables
  • Participants were offered make-up lessons in the event of unforeseen circumstances
  • Participants in the intervention group were asked to keep a seven-day food and exercise diary during one week of each month for six months. These were used to provide feedback and guidance based on current recommendations to prevent weight gain.

Statistical Analysis

  • Linear regression
  • Analyses of variance
  • P<0.05
  • SAS version 8.1 (SAS Institute, Inc, Cary, North Carolina).

 

Data Collection Summary:

Timing of Measurements

  • Baseline
  • Every month for six months.

Dependent Variables

  • Weight
  • BMI
  • Waist circumference
  • Blood pressure
  • Intake of fruits and vegetables
  • Quality of life beliefs. 

Independent Variables

  • Education
  • Provision of fresh fruits and vegetables. 


 

Description of Actual Data Sample:
  • Initial N: 40 females
  • Attrition (final N): 37
  • Age: Range 22 to 66 years old
  • Ethnicity: African American
  • Anthropometrics: Average BMI defined as obesity class I
  • Location: East Baton Rouge Parish in Louisiana.
Summary of Results:
  • The program retention rate was 93%
  • Participants in the intervention group lost a mean weight of 2.0kg, while participants in the control group gained a mean weight of 1.1kg at six months
  • Overall participants showed a mean decrease in weight of 0.4kg (SD 3.0kg), but the intervention group lost significantly more weight and had decreased body mass index at six months
  • In the intervention group, the average number of servings consumed per day of fruits, fruit juice and vegetables significantly increased at six months.
Author Conclusion:

The Rolling Store, at least on the small scale on which it was implemented, is a feasible approach to producing weight loss and improvements in healthy eating when combined with an educational program in a small community center.  

Funding Source:
Government: United States Department of Agriculture, Agricultural Research Service
University/Hospital: Lower Mississippi Delta Nutrition Intervention Research Initiative
Other:
Reviewer Comments:

Small sample size. 

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) 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.) 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.) 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? 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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? ???
  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.) ???
  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? ???
  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? N/A
  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? N/A
  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