Food Protection Trends - September/October 2020 - 336

TABLE 2. Percent (%) of respondents per location interviewed by phone
Location (Zip Code)

% of Total Sample
Pre-campaign
(n = 305 respondents)

Post-campaign
(n = 305 respondents)

17
16
4
20
17
26

15
17
2
22
17
27

28303
28304
28305
28306
28311
28314

surveys conducted on a regular basis by the Department of
Health and Human Services, Food and Drug Administration
(DHHS FDA; 18), different formats for survey questions
were used to assess the quality, content, and impact of the
"160° is Good" campaign (Table 2), such as multiple choice,
short response, and open-ended free response questions, to
make it less daunting for respondents to answer questions
and to allow respondents to expand upon their opinions
and experiences if inspired to do so. These questions
focused on respondents' perceptions of beef food safety,
thermometer usage, and food/beef handling practices. A
minimum of 300 respondents were needed for both the
pre- and post-campaign phone surveys (i.e., ≥ 600 total
respondents, with no duplicate numbers used for pre- and/
or post-campaign surveys). With a sample size of at least
300 respondents within the target area population of ca.
210,000 citizens, the confidence level for the results are
95%, with a 5.61 confidence interval (29). Respondents
were residents of the test market area who prepared meals
at home and who specifically cooked burgers. The phone
surveys were conducted on behalf of the contracted
marketing/advertising company by an independent
third-party research marketing firm, and the results were
provided to the STEC CAP campaign development team.
According to Steber (34), a phone survey should last ca. 15
min. The baseline pre-campaign survey was completed in
May of 2017, just prior to the launch of the "160° is Good"
campaign, as a method to uncover current beliefs and
behaviors associated with cooking beef burgers. The postcampaign phone survey was conducted in September of
2017, ca. two weeks after the campaign ended, to measure
advertising effectiveness and visibility as well as to identify
any attitude or behavioral changes that may have occurred
as a result of the campaign.

336

Food Protection Trends September/October

Demographic characteristics of respondents
As detailed in Table 3, respondent characteristics consisted
of age group; gender; marital status; number of children
under age 18 in household; number of people in household;
employment status; Hispanic, Latino, or Spanish; race;
education level, and household income. There were no
significant differences in the demographic characteristics
between the pre- and post-campaign respondents and any
shifts in attitudes or behaviors were therefore not likely
due to sample fluctuations but rather to real changes that
occurred in the population surveyed.
Conduct of phone interview
All phone calls emanated from the central interviewing
facilities of the third-party independent research marketing
firm. This firm accessed a database of landline and cellular
numbers available from telephone companies and called
potential participants until the target sample of at least
300 fully completed surveys was reached for both the preand post-intervention surveys. Calls were recorded and
quality control conducted to ensure that recorded answers
in the data collection forms were accurate. Only trained
and experienced interviewers dialogued with respondents
on phone calls and collected the data so as to achieve the
high-quality, reliable, and valid information necessary for
research purposes (19). Each interviewer was fully briefed
on the proper administration of the questionnaire prior to
respondent contact. Also, supervisors monitored interviews
while in progress to ensure accuracy and completeness of the
data being collected.
Data analyses
The independent research marketing firm collected all
phone survey data and imported these data in tabular form
into Excel (Microsoft, Redmond, WA). This third-party

Food Protection Trends - September/October 2020

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