Attributes in stated preference elicitation studies on colorectal cancer screening and their relative importance for decision-making among screenees: a systematic review

Advancing Colorectal Cancer Detection With Blood-Based Tests: Qualitative Study and Discrete Choice Experiment to Elicit Population Preferences

BACKGROUND

Colorectal cancer (CRC) is the second most deadly form of cancer, inducing an estimated 1.9 million incidence cases and 0.9 million deaths worldwide in 2020. Despite the availability of screening tests, their uptake remains suboptimal. However, blood-based tests that look for signs of cancer-specific markers in the body are increasingly available as an alternative for more invasive tests for cancer. Compared with existing tests, the benefits of blood-based tests for CRC include not needing pretest preparation, stool handling, and dietary or medication restrictions.

OBJECTIVE

This study aims to explore the population's preferences for CRC screening tests, with a focus on blood-based tests, and investigate the factors influencing test uptake.

METHODS

We used a mixed methods approach, combining semistructured interviews and a discrete choice experiment (DCE) survey. Interviews were analyzed using thematic analysis to identify salient attributes for CRC screening tests. These attributes informed the design of the DCE survey. The DCE data were analyzed using mixed logit and mixed-mixed multinomial logit models.

RESULTS

Qualitative findings from 30 participants revealed that participants preferred blood-based tests due to their perceived low risk, minimal pain, and ease of sample collection. However, concerns about the test's lower accuracy were also expressed. The DCE survey was completed by 1189 participants. In the mixed logit model, participants demonstrated a stronger preference for blood-based tests over a 2-day stool-based test. The mixed-mixed multinomial logit model identified 2 classes, strong supporters and weak supporters, for CRC screening. Weak supporters, but not strong supporters, had a higher preference for blood-based tests. Women, ethnic Chinese, and people aged 40 to 60 years were more likely to be weak supporters. Both models highlighted the high influence of cost and test sensitivity on participants' preferences. Transitioning from a 2-day stool-based test to a blood-based test, assuming a national screening program at a base price of Singapore $5 (US $3.75), was estimated to have the potential to increase the relative uptake by 5.9% (95% CI 3.6%-8.2%).

CONCLUSIONS

These findings contribute to our understanding of CRC screening preferences and provide insights into the factors driving test uptake. This study highlights the perceived advantages of blood-based tests and identifies areas of concern regarding their accuracy. Further research is needed to determine the actual increase in uptake rate when blood-based tests are made available.

A discrete choice experiment to elicit preferences for a chronic disease screening programme in Queensland, Australia

OBJECTIVE

Patient-centred care, increasingly highlighted in healthcare strategies, necessitates understanding public preferences for healthcare service attributes. We aimed to understand the preferences of the Australian population regarding the attributes of chronic disease screening programmes.

STUDY DESIGN

The preferences were elicited using the discrete choice experiment (DCE) methodology.

METHODS

A DCE was administered to a sample of the Australian general population. Respondents were asked to make choices, each offering two hypothetical screening scenarios defined by screening conduct, quality and accuracy of the test results, cost to the patient, wait time and source of information. Data were analysed using a panel mixed multinomial logit model.

RESULTS

A strong preference for highly accurate screening tests and nurse-led screenings at local health clinics was evident. They expressed disutility for waiting time and out-of-pocket costs but were indifferent about the source of information. Their preference for a nurse-led programme was highlighted by the fact that they were willing to pay $81 and $88 to get a nurse-led programme when they were offered a general practitioner-led and a specialist-led programme, respectively. Furthermore, they were willing to pay $32 to reduce a week of waiting time and $205 for a 95% accurate test compared to a 75% accurate test. Preferences remained consistent irrespective of the respondent's place of residence.

CONCLUSIONS

Our findings highlight the importance of diagnostic test accuracy and nurse-led service delivery in chronic disease screening programmes. These insights could guide the development of patient-centric services by enhancing test accuracy, reducing waiting times and promoting nurse-led care models.