Pra-0345-ssb_2025-093025

United States Food and Drug Administration

Food Safety and Nutrition Survey

OMB Control No. or 0910-0345

SUPPORTING STATEMENT

Part B. Statistical Methods

1. Respondent Universe and Sampling Methods

The Food Safety and Nutrition Survey will use an addressed-base, mail push-to-web survey. A total of 5,000 respondents will be surveyed. Additionally, methods will be employed to see if response bias is a problem in the survey. Participation in the survey will be voluntary. Cognitive interviews and a pre-test will be conducted prior to fielding the survey. FDA is only planning on conducting this survey one time in the next three years.

Respondents to this collection include individuals or households who are randomly sampled. The respondents are adults, age 18 and older, drawn from the 50 states and the District of Columbia.

Address based sample frame:

The participant universe for this sample is all households with addresses in the United States. Eligible participants are defined as: aged 18 years or older, read English or Spanish, sufficiently good health to complete either an online or mail survey.

The sample of addresses will be selected from the ABS frame maintained by Marketing Systems Group (MSG), derived from the USPS Computerized Delivery Sequence (CDS) file and updated monthly. The sampling frame will be restricted to addresses identified in the CDS as residential (i.e., will exclude addresses identified in the CDS as business addresses).

We will randomize the assignment of questionnaire versions at the address level at the time of address sampling. Each sampled address will be assigned to receive one of the two versions, and the assignment will be such that one-half of sampled addresses are assigned to receive version 1 and the other half are assigned to receive version 2.

An invitation to complete the survey will be mailed to each address with instructions requesting that the person with the most recent birthday who is over the age of 18 complete the questionnaire via the Web. The same instructions will be used with the nonresponse, follow-up, hard copy questionnaire we will send if a representative from the household has not yet completed the survey.

2. Procedures for the Collection of Information

For the address-based sample, sampled addresses will be sent a letter on FDA letterhead explaining the study and inviting the potential respondents to respond to the survey via the Web at a URL provided in the letter and including two $1 bills. Two follow-up attempts containing similar information to the letter encouraging response via the Web will be sent. The first will be a reminder/thank-you postcard sent 5 days later to all households, and the second will be a postcard sent to all non-respondents 10 days after the first postcard. Next, a hard-copy questionnaire will be mailed to non-respondents 10 days later and finally, a reminder postcard for the mail survey will be sent 10 days after the mail survey to non-respondents encouraging them to participate in the study.

3. Methods to Maximize Response Rates and Deal with Non-response

To help ensure that the response rate is as high as possible, we will employ all appropriate methods demonstrated in the scientific literature on survey methodology. These procedures include the following:

• Design a questionnaire that minimizes participant burden (short in length, written in easy-to-understand language).

• Test the draft questionnaire using cognitive interviews to ensure that participants can properly understand the questions and that the response options are robust.

• Test the draft questionnaire in a pre-test to ensure that it is working as expected.

Address-based survey:

• We will send respondent invitations on FDA letterhead to participate in the survey. The letter will identify FDA as the sponsor of the survey, give a brief explanation of the study topic, and stress the importance of participation. Moreover, the letter will be signed by an FDA official at a level sufficiently high enough that they can be located on the FDA website, should the potential respondent desire to do this.

• We will allow respondents to choose their preferred method for responding to the survey; online or on paper. By using a multimode approach, those who are more comfortable filling out the survey online can do so, while those without access to the internet or who are less comfortable taking an online survey can respond via a paper and pencil version of the survey.

• We plan to use a fda.gov web address as a landing page for the survey. This will further promote the legitimacy of the survey since it will be a government webpage.

Non-response analysis:

Because survey estimates are calculated from the answers of those who complete the survey, there is potential for bias in the estimates if those who did not complete the survey differ systematically from those who do. Statistical adjustments used in computing survey weights may reduce such nonresponse biases, however, it is important to first assess the extent to which any biases exist. A variety of methods are available for evaluating nonresponse bias.

We will conduct a nonresponse bias analysis. We plan on conducting the following types of analysis: (1) benchmarking to external estimates; (2) examination of response rates for subgroups; and (3) comparison of base-weighted and final-weighted estimates.

4. Test of Procedures or Methods to be Undertaken

FDA plans to perform both cognitive interviews and pre-tests to minimize collection burden on participants and improve quality of collected information.

The survey will be pre-tested with up to 100 participants shortly after OMB approval of the information collection.

Representatives of FDA and the contractor will monitor the pretest. Few changes to the questionnaire are expected from the pre-test, because many of the questions are carryovers from previous survey waves and have been pre-tested multiple times. OMB will be provided with copies of the final questionnaires prior to implementation of the study.

5. Individuals Consulted on Statistical Aspects and Individuals Collecting and/or Analyzing Data

The contractor, Westat, will collect the information on behalf of FDA. Simani Price, Ph.D. will serve as the project manager for the address-based. Data analysis and dissemination will be led by Amy Lando, MPP, Consumer Science Specialist at FDA.

References:

Gaziano, C. (2005). Comparative Analysis of Within-Household Respondent Selection Techniques. The Public Opinion Quarterly, 69(1), 124-157.

Rizzo, L., Brick, J.M., and Park, I. (2004). A minimally intrusive method for sampling persons in random digit dial surveys. Public Opinion Quarterly, 68(2), 267-274.

List of Appendices:

1. FSANS Food Safety Survey Cognitive Interview Screener

2. FSANS Nutrition Survey Cognitive Interview Screener

3. FSANS Food Safety Survey Mail Survey

4. FSANS Food Safety Survey Pretest

5. FSANS Food Safety Survey Final

6. FSANS Nutrition Survey Final

7. FSANS Nutrition Survey Final

8. FSANS Nutrition Survey Mail Survey

FSANS Nutrition Survey Pretest

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