Development and Testing of Food Safety Knowledge and Attitude Questionnaires for Use With Consumer Audiences

• Val Hillers, Washington State University
• Lydia Medeiros, The Ohio State University

Assisted by:

• Verna Bergmann, Washington State U.
• Gang Chen, Ohio State U.
• Pat Kendall, Mary Schroeder, Colorado St. U.

Food Safety Education: What Should We Be Teaching?

Step one: Identification of major themes (control factors) for food safety education

We suggest emphasis on behaviors associated with the most prevalent foodborne illnesses (as identified by the CDC).

Medeiros, Hillers, Kendall, Mason. J. of Nutrition Education 33:108-113, 2001

Five Major Control Factors for Pathogens

• Practice personal hygiene
• Cook foods adequately
• Avoid cross-contamination
• Keep foods at safe temperatures
• Avoid foods from unsafe sources

What Food Safety Behaviors Are Most Important in Preventing Foodborne Illness?

Step 2: Developed consensus among food safety experts (n=24) about the most important behaviors to reduce risks of foodborne illnesses from home food preparation.

Summary of Expert Panel Recommendations

Twenty-nine behaviors that are associated with pathogens and foodborne illness were ranked according to their importance in preventing foodborne illnesses.

The behaviors are grouped according to the five major control factors for pathogens.

Step 3: The research team received funding from USDA to develop evaluation tools for food safety educators.

Goal: Develop Valid and Reliable Questionnaires

• Knowledge of recommended food safety behaviors
• Attitudes regarding recommended food safety behaviors
• Food safety behaviors

Development of Questions

A sub-group (n=8) from the Expert Panel attended a meeting to write at least one knowledge and one attitude question related to each of the 29 messages that originated from the Expert Panel.

Items were reviewed by tri-state team, cooperative extension faculty, questionnaire experts and end-users.

Reviewers looked for ambiguous wording, unclear format and appropriateness of questions for a low-literacy audience.

Ambiguous items were discarded or re-worded for more acceptable phrasing.

Assessment of Validity

• Content validity: used guidelines from the panel of food safety experts.
  • Review of questions by persons with expertise in food safety, nutrition, questionnaire development.
• Face validity: reviewed by wide variety of people who represented target audiences.

Pilot-testing the Questionnaires

• Knowledge questionnaire: 43 items
  • Cooperative Extension groups
    • Pretest, intervention, post-test (n=58)
    • Test, no intervention, re-test (n=19)
  • College students
    • Prestest, intervention, post-test (n=79)

Pilot-testing the Questionnaires

• Attitude questionnaire: 49 items
  • Cooperative Extension n=30
  • College students
    • Non-majors (n-138)
    • Majors (n=57)

Development of Final Questionnaires

• Questionnaires from the pilot-tests were statistically analyzed.
• Findings were used to develop shortened versions of the questionnaires.
  • Knowledge: 18 items
  • Attitude: 10 items
• The short forms were re-tested.

Knowledge Questionnaire: Item Analysis

• Difficulty Scores (% answering correctly)
  • Should be between 20 and 80%
  • Four questions of final 18 were too easy.
    • 1 on personal hygiene
    • 3 on cross-contamination
  • These questions were retained in the final questionnaire because the concepts were rated as very important by the expert panel.

Knowledge Questionnaire: Instrument Sensitivity

• Changes in mean scores following an educational program.
  • For each of the 18 questions, there was a sig. difference (p<.05) in mean values between pre and post test.
• Control (with no intervening instruction)
  • No significant difference between test and re-test scores.

Knowledge Questionnaire: Reliability

• Test-retest: Coefficient of stability for 18-item questionnaire was 0.81
  • Should be at least 0.7*.
• Internal Consistency: Cronbach’s alpha >0.75 for extension participants and college students.
  • Should be at least 0.7*.

*Parmenter and Wardle, JNE 32:269; 2000.

Attitude Scale: Item Analysis

• Ten items met statistical criteria for inclusion in the final food safety attitude scale.
  • One item was accepted that was judged too easy
  • Two were accepted that did not meet construct validity standard
  • These 3 items were otherwise statistically acceptable.
• No items related to personal hygiene were judged acceptable.

Attitude Scale: Reliability, Construct Validity

• Test/retest: Correlation of test and retest responses was highly significant (P>01) for each of the 10 items.
• Extreme Group Comparison: group with greater knowledge of food safety had higher mean scores indicating a more positive attitude toward food safety.

Attitude Scale: Internal Consistency (Cronbach a)

Summary

These food safety knowledge and attitude questionnaires are among the first to be tested for validity and reliability.

They are relatively short and should pose little respondent burden.

They were designed to be used with a wide variety of audiences.

Potential Uses of Questionnaires

• Assess subject matter knowledge before and after a food safety educational program.
• Assess attitudes to help explain food safety behavior or the likelihood that someone will change behavior after an educational intervention.
• Determine food safety knowledge and attitudes of a population for research purposes.