HD: Food Security (2011)

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

To examine the relationship between household food security and measures of functional health status in a rural, low-income area.

Inclusion Criteria:
  • Adults
  • Living within Athens, Ohio, and surrounding counties
  • Recruited into study from either a health care encounter in a rural, university-based primary care facility (includes familty practice, internal medicine and gerontology clinics) or community-based programs.
Exclusion Criteria:

Not provided.

Description of Study Protocol:

Recruitment

  • Clinic-based samples were adult patients having a health care encounter in a rural, university-based primary care facility
  • Community-based samples were adults recruited at community fairs, festivals or food distribution programs for low-income families or parents of children receiving services through a mobile immunization clinic
  • Survey teams manned tables to recruit participants at locations. Help was provided, if requested, to complete the survey.
  • Participants received a $5.00 gift certificate to a local grocery store for compensation for time and effort.

Design

  • Data was taken from the study previously designed to evaluate differences in health status indicators, health care system use and health care access among patients seen in rural primary care clinics vs. those in a community-based sample
  • Survey was completed by study participants at one point in time
  • Cross-sectional survey.

Statistical Analysis

  • Chi-square test was used to compare sample demographic characteristics between clinic and community samples
  • Analysis of variance was used to examine differences between food security categories and the scale scores of the SF-36 (Medical Outcome Study Short Form-36)
  • Linear regression was used to examine the relationship of study variables.
Data Collection Summary:

Timing of Measurements

  • One-time self-administered survey at recruitment
  • 12-page survey that included demographic questions, information about access to and utilization of health care services, co-morbid health problems, the USDA Core Module questions and the SF-36.

Dependent Variables

  • Functional health and well-being, measured by the SF-36
  • Eight health concepts were measured
    • Physical functioning
    • Role limitations because of physical health problems
    • Bodily pain
    • General health
    • Vitality
    • Social functional
    • Role limitations because of emotional problems
    • Mental health.

Independent Variables

  • Food security, measured by USDA Core Module questions
  • Categories of food security include
    • Food secure
    • Food insecure without hunger
    • Food insecure with "moderate" hunger
    • Food insecure with "severe" hunger.

Control Variables

  • Age
  • Gender
  • Race
  • Marital status
  • Education
  • Gross household income.
Description of Actual Data Sample:

Initial N

Unknown.

Attrition (Final N)

  • N=1,006
  • 60% in clinic-based sample (N=605)
  • 40% in community based sample (N= 401).

Age

  • Community sample: 28% over the age of 60
  • Clinic sample: 22% over the age of 60 (P=0.02).

Ethnicity

White: 849/1006 (84%).

Other Relevant Demographics

  • Female: 630/1006 (63%)
  • Community sample more likely to be married: 65% vs 56% (P<0.005)
  • Community sample less likely to have graudated from high school: 28% vs 17% (P<0.001)
  • Community sample more likely to have gross household income less than $20,000 per year: 62% vs. 38% (P>0.001).

Location

  • Athens, Ohio, and surrounding counties
  • Appalachian region of Ohio.

Characteristics of Participants by Food Security Status

Variables

Food Secure (Total N=779)
N (%)

Food Insecure (N=227)
N (%)

Statistical Significance of Group Difference

Age (years)

20-39

248 (32)

128 (51)

P<0.001

60+

227 (29)

18 (8)

P<0.001

Race: White

679 (88)

170 (76)

P<0.001

Marital Status: Married
492 (63)
109 (48)
P<0.001
Education: < High School Graduate
146 (19)
69 (31)
P<0.001
Health Status: Fair or Poor
187 (25)
101 (47)
P<0.001

Summary of Results:

Key Findings

  • 227 (23%) reported some level of food insecurity
    • 74 (7%) reported food insecure without hunger
    • 55 (5%) reported food insecure with moderate hunger
    • 98 (10%) reported food insecure with severe hunger.
  • 779 (77%) reported food security.

Medical Outcome Study Short Form 36 (SF-36) by Food Security Category
Expressed as means ±SD

Outcome Category Food Secure Food Insecure Without Hunger Food Insecure with Moderate Hunger Food Insecure with Severe Hunger
Physical Functioning
70±31
54±34**
63±30*
57±30***

Physical Role Limitations

60±44
49±44*
38±40***
42±41**
Bodily Pain
60±27
46±27***
50±27**
47±28***
General Health
62±23
48±23***
47±23***
45±22***
Social Functioning
74±27
57±30***
51±30***
53±26***
Emotional Role Limitations
69±40
48±45**
50±43**
42±44***
Mental Health
61 (13)
57 (19)*
55 (17)**
53 (19)***

*P<0.05
**P<0.01
***P<0.001.

[Note: SF-36 scores range from one to 100, with higher scores indicating higher functioning.]

There were no significant differences among food insecurity groups for any measure; all significant differences are in reference to the food secure group.

 Other Findings

  • Mean Medical Outcome Study Short Form scores were significantly lower for food insecure respondents than food secure respondents
  • Food security status, completion of at least a high school education, Medicaid status and age (with the exception of the Mental Health Scale) all consistently demonstrated significant contributions to the medical outcome variables.
Author Conclusion:
  • Prevalence of food insecurity in this study was almost twice that expected on the basis of national probabiltiy samples
  • Minimal levels of food insecurity are associated with poor health status
  • Screening for food security status in settings with high risk populations may help clinicians rapidly identify significant problems related to health status.
Funding Source:
University/Hospital: Ohio University College of Osteopathic Medicine, Ohio University Vice-president for Research
Reviewer Comments:
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? N/A
  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? No
  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? No
  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? 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.) No
  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? 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? 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? 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? 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? 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? 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)? No
  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