Using Behavioural and Cultural Insights to Increase Colorectal Cancer Home-testing in Croatia

Using Behavioural and Cultural Insights to Understand and Address Barriers and Drivers to Colorectal Cancer Home-testing in Croatia

Colorectal cancer (CRC) is one of the leading causes of death in Croatia. An average of 3600 cases are diagnosed and an average of 2100 people die from the disease every year. Since 2007, Croatia has invited every man and woman aged 50-74 to participate in the home testing screening programme every two years. Currently only around 36% of the invited request the test-kit and 25% complete the home testing procedure, far below the target of 40-60%.

The Croatian Institute of Public Health with technical support from World Health Organization (WHO) Regional Office for Europe is undertaking a mixed-methods research study with the aim to increase the completion of colorectal cancer home testing and improve our knowledge of the barriers and drivers to do so. The study has a quantitative and a qualitative component:

1. Quantitative: testing the introduction of a reminder letter to encourage people to respond to the initial invite to participate in the CRC home test program and test which elements of a reminder letter improve response rates.

   The quantitative component consists of a four-arm reminder letter randomized controlled trial (RCT) comparing no letter, standard letter, behaviorally informed letter, and behaviorally informed letter sent with a home testing kit to investigate the effectiveness of reminders in increasing uptake of home-testing for colorectal cancer. Recruitment and data collection for the reminder letter trial will be conducted utilizing the routine screening process and routinely collected screening data.

2. Qualitative: conducting in-depth interviews with people from the target population who did or did not respond to the CRC invite letter and reminder to better understand the barriers and drivers to participation.

The qualitative component consists of 24 in-depth interviews (IDIs) conducted with members of the target population to identify barriers and drivers to completing colorectal cancer screening home-testing. Data collection for IDIs will be face-to-face, using discussion guides, and will be audio recorded. The audio-recordings will then be analyzed using a rapid analysis approach based on by the modified Capability-Opportunity-Motivation-Behavior (COM-B) framework.

Study Overview

• Status: Recruiting
• Conditions: Colorectal Cancer; Behavior Change
• Intervention / Treatment: Behavioral: Standard letter; Behavioral: Behaviorally informed letter; Behavioral: Home testing colorectal cancer kit

• Study Type: Interventional
• Enrollment (Estimated): 13000
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Veerle Snijders; Phone Number: +31642641587; Email: snijdersv@who.int
• Study Contact Backup: Name: Tiina Likki; Phone Number: +4531396157; Email: likkit@who.int

Study Locations

• Croatia
  • Zagreb, Croatia
    • Recruiting
    • Croatian Institute of Public Health
    • Contact: Ivana Brkić Biloš, MD; Email: ivana.brkic@hzjz.hr
    • Contact: Nataša Antoljak, Prof; Email: natasa.antoljak@hzjz.hr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• eligible to participate in the national colorectal cancer screening programme
• live in a study location (Split-Dalmatia or Zagreb City counties)
• did not respond to the cancer screening invite letter

Exclusion Criteria:

• participated in the colorectal screening programme in the last 24 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; Participants do not receive a reminder letter, which is treatment as usual.
Experimental: Standard letter; Participants receive a reminder letter which is based on the current colorectal cancer screening invitation.	Behavioral: Standard letter; A reminder letter to encourage recipients to order the colorectal cancer home testing kit, based on the current invite letter.
Experimental: Behaviorally informed letter; Participants receive a reminder letter which incorporates several behavioral components, including an active choice prompt, social norm, simplification, chunking and call to action.	Behavioral: Behaviorally informed letter; A reminder letter to encourage recipients to order the colorectal cancer home testing kit, with incorporates severally behaviorally informed components, including an active choice prompt, social norm, call to action, chunking and simplification.
Experimental: Behaviorally informed letter + testing kit; Participants receive the behaviorally informed letter plus the colorectal home testing kit, which removes the current barrier of having to request a kit.	Behavioral: Behaviorally informed letter; A reminder letter to encourage recipients to order the colorectal cancer home testing kit, with incorporates severally behaviorally informed components, including an active choice prompt, social norm, call to action, chunking and simplification.; Behavioral: Home testing colorectal cancer kit; The home testing kit is included with the reminder letter, instead of the usual process of responding to the letter to order the kit

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Home test kit ordered	Did the participant order the colorectal cancer home testing kit? Routinely collected data.	5 weeks
Completed colorectal cancer screening	Did the participant complete the home testing kit and return it to the health authority? Routinely collected data.	5 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opted out	Did the participant actively opt out of participating in the screening program? Routinely collected data.	5 weeks
Qualitative feedback	Qualitative feedback on the intervention arms and colorectal cancer screening experience. Collected through 24 semi-structured interviews.	10 weeks

Collaborators and Investigators

• Sponsor: Veerle Snijders
• Collaborators: Croatian Institute of Public Health; Andrija Štampar School of Public Health

Study record dates

Study Major Dates

• Study Start (Actual): March 5, 2024
• Primary Completion (Estimated): April 1, 2024
• Study Completion (Estimated): July 1, 2024

Study Registration Dates

• First Submitted: March 26, 2024
• First Submitted That Met QC Criteria: March 26, 2024
• First Posted (Actual): April 2, 2024

Study Record Updates

• Last Update Posted (Actual): April 2, 2024
• Last Update Submitted That Met QC Criteria: March 26, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: colorectal cancer; cancer screening; behavioral insights; communications
• Additional Relevant MeSH Terms: Digestive System Diseases; Neoplasms; Neoplasms by Site; Gastrointestinal Neoplasms; Digestive System Neoplasms; Gastrointestinal Diseases; Colonic Diseases; Intestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Colorectal Neoplasms
• Other Study ID Numbers: ERC0003996

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The study utilizes the data that is routinely collected as part the Croatian National Screening Database, only specific approved members of the screening program are able to access and utilize this data. For this reason, it is currently not planned to share individual participant data.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No