EAL

Scheduled Maintenance: Saturday, May 4th, starting at 8PM EST
We will be upgrading some systems and expect the maintenance to last no more than 2 hours. During the maintenance window, you will not have access to this portal.

MHFS: Food Safety (2012-2013)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The purpose of this analysis was to evaluate endogeneity and reporting bias in a set of self-reported food practices measures and to examine cognitive antecedents of these measures in light of these biases. To achieve this, models of food safety practices that incorporate a full set of measures of possible cognitive antecedents of good food and safety practices were evaluated.

Inclusion Criteria:

For the purpose of this analysis, the 1998 FDA/USDA Food Safety Survey was used to capture the cognitive antecedents of safe food practices.

Exclusion Criteria:

Not described.

Description of Study Protocol:

Recruitment

A sampling system called GENESYS was used to conduct a nationally-representative single-stage sample of telephone numbers and the respondent from each household was selected by the last birthday method.

Design

Cross-sectional survey.

Statistical Analysis

Regression was used to estimate models that incorporate the same set of cognitive antecedents for each of three indexes of food practices
Ordinary least squares (OLS) models that includes the endogenous variable, FISHPREP and a two-stage least square (2SLS) model that uses geographic region as an instrument variable were used. The results of the models are used to test hypotheses concerning the presence of endogeneity and reporting biases.
All regressions and tests reported in this section were conducted using standard programs within Stata, version 8.

Data Collection Summary:

Timing of Measurements

The 1998 FDA/USDA Food Safety Survey was used to capture the cognitive antecedents of safe food practices.

Dependent Variables

Self-reported practices related to preparing food, eating potentially risky foods and cooling cooked foods. These practices are combined into three summary indexes: PREPNDX, EATRISKY and COOLNDX.
The experience variable most directly relevant to food preparation is FISHPREP, measured by a question that asked whether the respondent prepares fish
Three other measures of prior experience is often a critical determinant of cognitive elements were considered
- How much of the food preparation in the household is done by the respondent (COOKMEALS)
- Whether there are children younger than five years old in the household (CHILD <5)
- Whether the respondent or someone else in the household had a recent foodborne illness episode (FOODSICK).
To test for the possibility that knowledge may have a non-linear effect on food safety practices, the six questions were divided into two scales:
- COMMONGERM is based on awareness of two widely known microbial pathogens: Salmonella and E. coli
- UNCOMMON-GERM is based on awareness of four less widely-known pathogens: Campylobacter, Listeria, Vibrio vulnificus and Cyclospora.

Independent Variables

Cognitive antecedents of safe food practices.

Description of Actual Data Sample:

Initial N: The 1998 survey had a sample of 2,001 adults
Attrition (final N): 2,001 adults (OLS estimate for males, -0.40; females, 0.00)
Age: Adults 18 years of age and older.

Ethnicity

OLS estimates

Black non-Hispanic: -0.02
Hispanic: 0.49
Other: 0.16
Race refused: 0.15
White, non-Hispanic: 0.00.

Other Relevant Demographics

Not reported.

Anthropometrics

Not reported.

Location

Maryland.

Summary of Results:

Key Findings

An assessment of measurement biases shows that endogeneity of food choices affects reports of food preparation
Response bias affects reports of cooling practices as evidenced by its relation to knowledge and information search, a pattern of cognitive effects unique to cooling practices
11% of respondents report one or more unsafe cooling practices, 54% of respondents report at least one unsafe eating behavior, 63% of respondents report at least one unsafe preparation practice (15%, 27%, 56% and 31% of respondents report unsafe preparation of fish, meat or chicken eggs and improper hand-washing)
Self-reported food preparation practices are modestly correlated in the expected way to consumption and cooling practices, however are unrelated in an unexpected manner. Unsafe eating practices are weakly correlated with safer cooling practices.
The hypothesis of consistent OLS estimates is rejected for PREPNDX. The results indicate that endogeneity could affect the OLS results for this measure and that parameter estimates should be obtained using a 2SLS procedure.

Author Conclusion:

Results show that practice-specific risk perceptions are the primary cognitive antecedents of safe food behavior, which has implications for the design of effective education messages about food safety
This analysis has implications for optimizing education efforts to encourage safer behavior in food-handling and similar behavioral domains
In the future, it may be more effective to focus on raising self-awareness among consumers about their own behavior.

Funding Source:

Government:

Center for Food Safety and Applied Nutrition, US Food and Drug Administration

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)	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?		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)	Yes
	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")?	N/A
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?	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?	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?	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