Potential screening participants’ and physicians’ preferences on optimizations of population based colorectal cancer screening, a discrete choice experiment

RATIONALE
Population based screening for colorectal cancer (CRC) has successfully been enrolled in the Netherlands since 2014. For this, adults aging from 55-75 years, are invited to provide a stool sample for detection of occult blood (fecal immunochemical test [FIT]) every two years, with a follow-up colonoscopy in case of a positive result. However, FIT sensitivity and specificity are suboptimal, resulting in unnecessary colonoscopies in over 20% of patients with a positive FIT. The invasive nature and associated healthcare costs warrant a better selection of individuals that require a colonoscopy, for example by biomarkers in breath or stool samples.
High adherence rates of a population-based screening program are important to achieve reduction of cancer related mortality. The process of screening is complex and involves patients as well as providers. Understanding participants’ and physicians’ preferences may help choosing better screening options and ultimately lead to higher attendance rates. We aim to elicit screening participants’ and physicians’ preferences towards optimizations for population-based CRC screening.

OBJECTIVES
- To determine participants’ and physicians’ preferences regarding the use of additional breath- or fecal sampling to improve population-based screening
- To predict the relative importance of different screening strategies in participants and physicians
- To predict the uptake of CRC screening with various test strategies
- To identify differences in preference among different subgroups

STUDY DESIGN
The present study will be conducted as a discrete choice experiment. Subjects will be asked to choose between two hypothetical CRC screening strategies with 4-6 attributes, the current CRC screening program, or to opt-out (no screening) in 10 varying questions .

STUDY POPULATION
A random selection of patients between 50-75 years from the municipal database of Nijmegen will be sent a questionnaire. Additionally, practicing gastroenterologists and general practitioners in the Netherlands will be invited to fill in the questionnaire.

MAIN STUDY ENDPOINTS
Patient and physician preferences, expressed in the utility of each individual attribute and the relative importance of the selected attributes.

NATURE AND EXTEND OF THE BURDEN AND RISKS ASSOCIATED WITH PARTICIPATION, BENEFID AND GROUP RELATEDNESS
The burden for study participants is low. Subjects will be asked to perform a series of choice tasks to assess their preferences on optimization strategies for the CRC screening program. The questionnaire consists of approximately 10 short choice tasks, which will take around 15 minutes to complete. To ensure privacy and confidentiality, all study data will be anonymized. No healthcare risks are associated with participating.
Included patients will not directly benefit from this investigation. However, this study will give valuable insights in participants’ and physicians’ preferences and can help future policy making on improvement on population-based CRC screening, lowering the colonoscopy burden on patients, as well as on healthcare accessibility. As such, we consider the balance between risks and discomfort for patients (low) and benefit for the future population (potentially high) acceptable.

Individuals have preferences towards certain attributes of CRC screening optimizations

Participants are invited to fill in the quesstionnaire. A reminder will be sent once after 1 month.

Questionnaire