THE EFFECT OF FOOD SAFETY TRAINING ON EMPLOYEES' KNOWLEDGE, ATTITUDES, AND PRACTICES: A SOLOMON FOUR-GROUP EXPERIMENT (SOLOMON-KAP)

May 2, 2026 updated by: Müncübe Duman Erbakırcı, Kayseri University

THE EFFECT OF FOOD SAFETY TRAINING ON KNOWLEDGE, ATTITUDE AND PRACTICES (KAP) OF FOOD INDUSTRY EMPLOYEES: AN EVALUATION USING THE SOLOMON FOUR-GROUP EXPERIMENTAL DESIGN

This study was designed as a randomized controlled trial using a Solomon four-group experimental design to evaluate the effectiveness of a food safety training program. The study was conducted among food service employees working in municipal facilities. The Solomon four-group design was used to control for potential pretest sensitization effects while assessing the true impact of the intervention. Participants were randomly assigned to four groups using a randomization method. Each group included approximately equal numbers of participants. The intervention consisted of a face-to-face food safety training program developed based on identified needs. The training content included personal hygiene, food safety principles, and safe food preparation practices. The training sessions were delivered in structured modules. Data were collected using a structured questionnaire developed based on the literature and expert opinions. The questionnaire included sections assessing participants' knowledge, attitudes, and practices related to food safety. Pre-test and post-test assessments were conducted according to the Solomon four-group design. Data collection procedures and study implementation followed standardized protocols to ensure consistency. Participants were adults aged 18 years and older, able to communicate effectively, and voluntarily agreed to participate in the study. Ethical approval was obtained prior to the study, and all participants provided informed consent.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Methods Study Design and Setting This study was designed as a randomized controlled trial employing a Solomon four-group experimental design to evaluate the effectiveness of a food safety training program. The study was conducted among food industry employees working in municipal social facilities. The Solomon four-group design was selected to assess the true effect of the intervention while controlling for potential pretest sensitization bias, thereby strengthening both internal and external validity.

Participants and Sample Size A total of 278 food industry employees working in municipal facilities were assessed for eligibility. Sample size calculation was performed using the Epi Info software based on an assumed food safety training prevalence of 85.9%, derived from previous studies, with a 5% margin of error and a 95% confidence interval. The minimum required sample size was calculated as 186 participants. To account for potential data loss, this number was increased by 10%, resulting in a final target sample size of 200 participants.

Eligible participants were adults aged 18 years or older, employed in the food sector, and possessing at least basic literacy skills. Individuals who declined participation or had communication barriers were excluded from the study.

Reasons for exclusion and participant flow throughout the study are presented in Figure 1.

Randomization and Group Allocation Following eligibility assessment and informed consent, 200 participants were randomly allocated into four groups using a random numbers table, with 50 participants assigned to each group. The randomization process, group allocation, intervention exposure, follow-up, and final analysis numbers are summarized in Figure 1.

  1. Intervention Group 1 (Pretest + Training + Posttest)
  2. Intervention Group 2 (Training + Posttest)
  3. Control Group 1 (Pretest + Posttest)
  4. Control Group 2 (Posttest only) The flow of participants through the study and group allocation process is illustrated in Figure 1.

Intervention Development of Training Content Baseline data obtained from Intervention Group 1 and Control Group 1 (the pretested groups) were analyzed to identify gaps in food safety knowledge, attitudes, and practices. These baseline findings were used to inform and tailor the content of the food safety training program, ensuring that the intervention addressed participants' identified needs.

Based on this needs assessment, a structured training program consisting of three modules was developed:

  1. Personal hygiene knowledge, attitudes, and practices
  2. Workplace hygiene knowledge, attitudes, and practices
  3. Safe food preparation processes Delivery of the Training Program The training intervention was delivered face-to-face by the research team in designated training halls within municipal facilities. The program consisted of three sessions, each comprising a 35-minute structured lecture followed by a 10-minute question-and-answer and discussion period. A 15-minute break was provided between sessions, and a maximum of 25 participants attended each session.

Participants in the intervention groups received the training program, whereas no intervention was applied to the control groups during the study period. To ensure ethical standards, control group participants were offered the same training after completion of posttest data collection.

Data Collection Instruments Data were collected using a structured questionnaire developed by the researchers based on relevant literature and expert consultation. The questionnaire comprised five sections with a total of 64 items assessing sociodemographic characteristics, previous food safety training, food safety knowledge, attitudes and practices. A pilot test was conducted with 10 food industry employees prior to data collection, and necessary revisions were made to improve clarity and relevance. The timing of pretest and posttest assessments, as well as the two-month follow-up period, are illustrated in Figure 1.

Details of the questionnaire items and scoring procedures are provided in the Supplementary Material.

Study Type

Interventional

Enrollment (Actual)

200

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Being 18 years of age or older
  • Working in the food sector
  • Having at least basic literacy skills

Exclusion Criteria:

  • Refusing to participate in the study
  • Having communication difficulties

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: CONTROL GROUP 1
Pretest assessment
Other: Pretest assessment
The reminder effect of the pretest will be evaluated.
Other: CONTROL GROUP 2
Other: Pretest assessment
The reminder effect of the pretest will be evaluated.
Experimental: INTERVENTION 1
Food safety training program
Other: Pretest assessment
The reminder effect of the pretest will be evaluated.
Other: Food safety training program
The interventions consisted of a structured face-to-face food safety training program covering personal hygiene, workplace hygiene, and safe food preparation practices.
Experimental: INTERVENTION 2
Food safety training program
Other: Food safety training program
The interventions consisted of a structured face-to-face food safety training program covering personal hygiene, workplace hygiene, and safe food preparation practices.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Score change
Time Frame: In the control group, the post-test was administered 8 weeks after the pre-test, while in the intervention group, the post-test was administered 8 weeks after the training was provided.

No standardized scale was used in the study. The questions in the questionnaire were developed based on expert opinions. There is no cut-off point or defined score range for the scores obtained from the questions. The questionnaire used in the study was developed by the researchers based on a literature review and consisted of five sections and 64 questions. The first section of the questionnaire (questions 1-10) included the socio-demographic characteristics of the employees; the second section (questions 11-15) included their status of receiving training on food safety; the third section (questions 16-35) assessed their knowledge about food safety; the fourth section (questions 36-45) assessed their attitudes toward food safety; and the fifth section (questions 46-64) assessed their food safety practices.

For the statements in the third section, participants selected the option that best suited them from "True," "False," or "I don't know." Participants received 1 point for each que
In the control group, the post-test was administered 8 weeks after the pre-test, while in the intervention group, the post-test was administered 8 weeks after the training was provided.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Kayseri University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2023

Primary Completion (Actual)

January 15, 2023

Study Completion (Actual)

June 30, 2023

Study Registration Dates

First Submitted

March 10, 2026

First Submitted That Met QC Criteria

May 2, 2026

First Posted (Actual)

May 7, 2026

Study Record Updates

Last Update Posted (Actual)

May 7, 2026

Last Update Submitted That Met QC Criteria

May 2, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2021/799
  • SOLOMON-KAP STUDY (Other Identifier: SOLOMON-KAP STUDY)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Preventing shared data from influencing the responses of other participants

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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