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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
200

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 15, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 10, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 2, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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Conditions

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