What Factors Influence Non-Participation Most in Colorectal Cancer Screening? A Discrete Choice Experiment

The Evolving Landscape of Discrete Choice Experiments in Health Economics: A Systematic Review

INTRODUCTION

Stakeholder preference evaluations are increasingly emphasized in healthcare policy and health technology assessment. Discrete choice experiments (DCEs) are the most common method for quantifying preferences among patients, the public, and healthcare professionals. While prior reviews (1990-2017) have examined DCE trends, no comprehensive synthesis exists for studies published since 2018. This updated review (2018-2023) provides critical insights into evolving methodologies and global trends in health-related DCEs.

METHODS

A systematic search (2018-2023) of Medline, Embase, and Web of Science identified relevant studies. Studies were screened for inclusion and data were extracted, including details on DCE design and analysis. To enable trend comparisons, the search strategy and extraction items aligned with previous reviews.

RESULTS

Of 2663 identified papers, 1279 met the inclusion criteria, reflecting a significant rise in published DCEs over time. DCEs were conducted globally, with a remarkable increase in publications from Asia and Africa compared with previous reviews. Experimental designs and econometric models have advanced, continuing prior trends. Notably, most recent DCEs were administered online.

DISCUSSION

The rapid growth of DCE applications underscores their importance in health research. While the methodology is advancing rapidly, it is crucial that researchers provide full transparency in reporting their methods, particularly in detailing experimental designs and validity tests, which are too often overlooked. Key recommendations include improving reporting of experimental designs, applying validity tests, following good practices for presenting benefit-risk attributes, and adopting open science practices. Ensuring methodological rigor will maximize the impact and reproducibility of DCE research in health economics.

Exploring public preferences and demand for ovarian cancer screening: a discrete choice experiment

Introduction

Routine population-level screening may in the future reduce the high mortality rates associated with late-stage ovarian cancer diagnosis. However, the voluntary nature of screening means that understanding the public's acceptability of the benefits, harms and likely uptake of any potential screening programme is crucial to implementation.

Objective

To measure public preferences towards the benefits and harms of a potential screening programme and to predict uptake.

Methods

An online Discrete Choice Experiment was completed by 250 women 40-80 years old in England and Wales. Subjects were asked 12 questions where they were asked to choose between two hypothetical screening tests described in terms of four attributes; ovarian cancer deaths, false-positive, false-negative and overdiagnosis rates, and no screening. Responses were analysed using mixed logit regression.

Results

In total, 250 women completed the survey. Ovarian cancer deaths (0.42, [95% CI: 0.40 - 0.44]) was the most important attribute overall, followed by the rate of false positive results (0.30, [95% CI: 0.30-0.30]). However, there were high levels of heterogeneity with individuals exhibiting low levels of worry about ovarian cancer (OR=1.76 [95% CI: 1.17-2.69]), low perceived risk of ovarian cancer (OR=1.44 [95% 1.03-2.03]) or risk-averse individuals (OR=1.46 [95% CI: 1.05-2.04]) significantly more likely to opt for the no screening alternative. Oppositely, individuals who regularly participate in cervical screening (OR=0.63 [0.47-0.90]) were less likely to opt for no screening. Overall, results indicated participants would be willing to accept 2.59 (95% CI: 1.82 - 3.36) false-negative results, 205 (95% CI: 161 - 248) false-positive results and 2.35 (95% CI: 1.76-2.94) per 10,000 people screened to avoid 1 ovarian cancer-related death. Uptake analysis confirmed a high willingness to undergo screening across varying levels of benefits and harms.

Conclusions

Currently ovarian cancer screening is not recommended as available screening methods do not offer benefits in terms of mortality reduction. The results of this study demonstrate a high demand for ovarian cancer screening and a willingness to trade between the benefits and risks of a potential test. Results of this study provide a useful resource for assessing the acceptability of future screening modalities which may become available.

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.

Colonoscopy surveillance in Lynch syndrome is burdensome and frequently delayed

Individuals with Lynch syndrome have an increased colorectal cancer risk, hence, biennial colonoscopy surveillance is recommended. We aimed to investigate patients' perception and preferences regarding surveillance, and to further explore compliance behaviour. Individuals with Lynch syndrome received a validated survey evaluating experiences of their three most recent colonoscopies. Individuals were non-compliant to surveillance if the interval between colonoscopies differed ≥ 6 months from the recommended interval. In total, 197 of 291 (68%) invited individuals returned the survey. They mostly underwent colonoscopy biennially (99%), under mild sedation (79%) and with bowel preparation performed by Moviprep® (99%). Surveillance was perceived as impacting quality of life in 21%, and as moderately to extremely burdensome in 57%, particularly in those below age 40. To lower the burden, patients prioritised improvements in volume and taste of bowel preparation, laxation-related bowel movements, waiting times, and a more personal and respectful approach of endoscopic staff. Additionally, many individuals (60%) would favour less-invasive surveillance modalities such as biomarkers. In total, 28% of individuals had delayed colonoscopy surveillance, predominantly for patient-related reasons. An additional 10% considered quitting/postponing surveillance. Upon multivariable analysis, patient-related delay was associated with low and medium education, history of ≤ 4 colonoscopies and having no hospital recall-system. Colonoscopy surveillance in Lynch syndrome is often experienced as burdensome, and frequently delayed. We identified determinants of surveillance behaviour in this population, and present potential interventions to reduce the burden and non-compliance rates.

Decision-making on colorectal cancer screening in Curaçao - interviews with the target population

BACKGROUND

During the first year of the population based colorectal cancer (CRC) screening program on Curaçao, about 20% of invitees participated. This study explored the target population's perceptions and awareness on CRC (screening), beliefs on the program provision, their preferences and information needs for informed decision-making.

METHODS

Semi-structured interviews with 23 individuals, who were not yet invited for CRC screening, were recorded, transcribed, coded and analyzed.

RESULTS

CRC (screening) was discussed in the context of personal health, where own responsibility and food were important. Cancer was perceived as an unpredictable disease that causes suffering and leads to death and was also associated with fear. Despite being aware of the program, most respondents were not familiar with the screening procedure. Provision of the screening program was regarded positively and as an opportunity to contribute to health improvement. This seemed related to the expressed trust in the Caribbean Prevention Center (program organizer). Respondents preferred to make independent decisions about CRC screening participation. A personal approach, visual aids and media were the preferred sources of information.

CONCLUSION

The results of our interviews suggest that it may be beneficial to provide information on CRC screening in Curaçao within the context of personal health. While including sensitivity to fears and respect for the autonomy of the target population. Finally, electronic media maybe useful in supporting informed decision-making.

Public Preference Heterogeneity and Predicted Uptake Rate of Upper Gastrointestinal Cancer Screening Programs in Rural China: Discrete Choice Experiments and Latent Class Analysis

BACKGROUND

Rapid increases in the morbidity and mortality of patients with upper gastrointestinal cancer (UGC) in high-incidence countries in Asia have raised public health concerns. Screening can effectively reduce the incidence and mortality of patients with UGC, but the low population uptake rate seriously affects the screening effect.

OBJECTIVE

We aimed to determine the characteristics that influence residents' preference heterogeneity for a UGC-screening program and the extent to which these characteristics predict residents' uptake rates.

METHODS

A discrete choice experiment was conducted in 1000 residents aged 40-69 years who were randomly selected from 3 counties (Feicheng, Linqu, and Dongchangfu) in Shandong Province, China. Each respondent was repeatedly asked to choose from 9 discrete choice questions of 2 hypothetical screening programs comprising 5 attributes: screening interval, screening technique, regular follow-up for precancerous lesions, mortality reduction, and out-of-pocket costs. The latent class logit model was used to estimate residents' preference heterogeneity for each attribute level, their willingness to pay, and the expected uptake rates.

RESULTS

Of the 1000 residents invited, 926 (92.6%) were included in the final analyses. The mean age was 57.32 (SD 7.22) years. The best model contained 4 classes of respondents (Akaike information criterion=7140.989, Bayesian information criterion=7485.373) defined by different preferences for the 5 attributes. In the 4-class model, out of 926 residents, 88 (9.5%) were assigned to class 1, named as the negative latent type; 216 (3.3%) were assigned to class 2, named as the positive integrated type; 434 (46.9%) were assigned to class 3, named as the positive comfortable type; and 188 (20.3%) were assigned to class 4, named as the neutral quality type. For these 4 latent classes, "out-of-pocket cost" is the most preferred attribute in negative latent type and positive integrated type residents (45.04% vs 66.04% importance weights), whereas "screening technique" is the most preferred factor in positive comfortable type residents (62.56% importance weight) and "screening interval" is the most valued attribute in neutral quality type residents (47.05% importance weight). Besides, residents in different classes had common preference for painless endoscopy, and their willingness to pay were CNY ¥385.369 (US $59.747), CNY ¥93.44 (US $14.486), CNY ¥1946.48 (US $301.810), and CNY ¥3566.60 (US $552.961), respectively. Residents' participation rate could increase by more than 89% (except for the 60.98% in class 2) if the optimal UGC screening option with free, follow-up for precancerous lesions, 45% mortality reduction, screening every year, and painless endoscopy was implemented.

CONCLUSIONS

Public preference heterogeneity for UGC screening does exist. Most residents have a positive attitude toward UGC screening, but their preferences vary in selected attributes and levels, except for painless endoscopy. Policy makers should consider these heterogeneities to formulate UGC-screening programs that incorporate the public's needs and preferences to improve participation rates.

Socio-demographic and cultural factors related to non-participation in the Dutch colorectal cancer screening programme

BACKGROUND

High participation rates are essential for a screening programme to be beneficial. To reach non-participants in a targeted manner, insight in characteristics of non-participants is needed. We investigated demographic differences between participants and non-participants in the Dutch faecal immunochemical test-based colorectal cancer (CRC) screening programme.

METHODS

In this population-based cohort study, we included all invitees for CRC screening in 2018 and 2019. Participation status, birth year, and sex were extracted from the Dutch national screening information system and linked to demographic characteristics from Statistics Netherlands, including migration background, level of education, socioeconomic category, household composition, and household income. A multivariable logistic regression was used to assess the association between demographic factors and participation.

RESULTS

A total of 4,383,861 individuals were invited for CRC screening in 2018 and 2019, of which 3,170,349 (72.3%) participated. Individuals were less likely to participate when they were single and/or living with others (single with other residents versus couple: odds ratio [OR] 0.34, 95% confidence interval [CI]: 0.31-0.38), had a migration background (e.g. Moroccan migrant versus Dutch background: OR 0.43, 95% CI: 0.42-0.44), or had a low income (lowest versus highest quintile: OR 0.45, 95% CI: 0.44-0.45). Although to a lesser extent, non-participation was also significantly associated with being male, being younger, receiving social welfare benefits and having a low level of education.

CONCLUSION

We found that individuals who were single and/or living with others, immigrants from Morocco or individuals with low income were the least likely to participate in the Dutch CRC screening programme. Targeted interventions are needed to minimise inequities in CRC screening.

Quantitative Benefit-Risk Assessment in Medical Product Decision Making: A Good Practices Report of an ISPOR Task Force

Benefit-risk assessment is commonly conducted by drug and medical device developers and regulators, to evaluate and communicate issues around benefit-risk balance of medical products. Quantitative benefit-risk assessment (qBRA) is a set of techniques that incorporate explicit outcome weighting within a formal analysis to evaluate the benefit-risk balance. This report describes emerging good practices for the 5 main steps of developing qBRAs based on the multicriteria decision analysis process. First, research question formulation needs to identify the needs of decision makers and requirements for preference data and specify the role of external experts. Second, the formal analysis model should be developed by selecting benefit and safety endpoints while eliminating double counting and considering attribute value dependence. Third, preference elicitation method needs to be chosen, attributes framed appropriately within the elicitation instrument, and quality of the data should be evaluated. Fourth, analysis may need to normalize the preference weights, base-case and sensitivity analyses should be conducted, and the effect of preference heterogeneity analyzed. Finally, results should be communicated efficiently to decision makers and other stakeholders. In addition to detailed recommendations, we provide a checklist for reporting qBRAs developed through a Delphi process conducted with 34 experts.

Patient Preferences for Colorectal Cancer Screening Tests in Light of Lowering the Screening Age to 45 Years

BACKGROUND & AIMS

In 2021, the US Preventive Services Task Force lowered the colorectal cancer (CRC) screening age to 45 years. We used conjoint analysis, a method that assesses complex decision making, to update our understanding on people's CRC screening test preferences in the context of new guidelines.

METHODS

We conducted a conjoint analysis survey among unscreened individuals ≥40 years at average risk for CRC to determine the relative importance of screening test attributes in their decision making (eg, modality, effectiveness at reducing CRC risk, bowel prep). We also performed simulations to estimate the proportion of people who would prefer each US Multi-Society Task Force (MSTF) on CRC-recommended test. The analyses were stratified among those aged 40-49 years (newly or soon-to-be eligible for screening) and ≥50 years (have been eligible).

RESULTS

Overall, 1000 participants completed the conjoint analysis (40-49 years, n = 456; ≥50 years, n = 544). When considering all 5 US MSTF-recommended tests, there were differences in test preferences between age groups (P = .019), and the most preferred test was a fecal immunochemical test (FIT)-fecal DNA every 3 years: 40-49 years, 34.6%; ≥50 years, 37.3%. When considering only the US MSTF tier 1 tests, most 40- to 49- (68.9%) and ≥50-year-olds (77.4%; P = .004) preferred an annual FIT over a colonoscopy every 10 years.

CONCLUSIONS

Our findings suggest that more than one-third of people may want to do a FIT-fecal DNA every 3 years for their CRC screening. When only considering US MSTF tier 1 tests, three-fourths of people may prefer an annual FIT over colonoscopy. Further research examining CRC screening test preferences among broader populations is warranted to inform and enhance screening programs.

Can healthcare choice be predicted using stated preference data? The role of model complexity in a discrete choice experiment about colorectal cancer screening

INTRODUCTION

The validity of discrete choice experiments (DCEs) is crucial to its usage in healthcare decision-making, but there is only a limited number of health contexts in which external validity is demonstrated. This study aims to assess the internal and external validity of the DCE in the context of colorectal cancer (CRC) screening, and gather insights into the discrepancy between stated and revealed preferences.

METHODS

Stated and revealed preferences were elicited on an individual level from Dutch residents eligible for CRC screening in a DCE and a field experiment, respectively (N = 568). To identify the determinants of CRC screening participation and their relative importance, five random utility maximisation models that varied in complexity were used. We assessed the accuracy with which the models based on stated preferences predict individual-level screening choice in a holdout task (internal validity) and in the actual screening choice (external validity). Insights into the discrepancy between stated and revealed preferences were gathered by comparing groups of respondents.

RESULTS

Our findings show high internal and external validity. Choices could be accurately predicted for 95% of the respondents in the holdout task, and 90% in the actual screening choice. When scale and preference heterogeneity were taken into account model fit improved; individual-level prediction accuracy slightly increased for the holdout task but not for the actual screening choice. Respondents for whom stated preferences matched revealed preferences were generally in better health and found the GP's support for their screening decision more important.

DISCUSSION

Evidence was found that revealed preferences can be predicted accurately on an individual level. Incorporating heterogeneity improved internal validity but not external validity. Differences between stated and revealed preferences can be attributed to respondents' health and the support of their GP. We suggest researchers to continue investigating the internal and external validity of discrete choice experiments, and the role of model complexity.

Preference Variation: Where Does Health Risk Attitude Come Into the Equation?

OBJECTIVES

Decisions about health often involve risk, and different decision makers interpret and value risk information differently. Furthermore, an individual's attitude toward health-specific risks can contribute to variation in health preferences and behavior. This study aimed to determine whether and how health-risk attitude and heterogeneity of health preferences are related.

METHODS

To study the association between health-risk attitude and preference heterogeneity, we selected 3 discrete choice experiment case studies in the health domain that included risk attributes and accounted for preference heterogeneity. Health-risk attitude was measured using the 13-item Health-Risk Attitude Scale (HRAS-13). We analyzed 2 types of heterogeneity via panel latent class analyses, namely, how health-risk attitude relates to (1) stochastic class allocation and (2) systematic preference heterogeneity.

RESULTS

Our study did not find evidence that health-risk attitude as measured by the HRAS-13 distinguishes people between classes. Nevertheless, we did find evidence that the HRAS-13 can distinguish people's preferences for risk attributes within classes. This phenomenon was more pronounced in the patient samples than in the general population sample. Moreover, we found that numeracy and health literacy did distinguish people between classes.

CONCLUSIONS

Modeling health-risk attitude as an individual characteristic underlying preference heterogeneity has the potential to improve model fit and model interpretations. Nevertheless, the results of this study highlight the need for further research into the association between health-risk attitude and preference heterogeneity beyond class membership, a different measure of health-risk attitude, and the communication of risks.

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

INTRODUCTION

The SIGMO study (Sigmoidoscopy as an evidence-based colorectal cancer screening test - a possible option?) examines screening eligible populations' preferences for colorectal cancer (CRC) screening in Germany using a discrete choice experiment (DCE). Attribute identification and selection are essential for the construction of choice tasks and should be evidence-based. As a part of the SIGMO study this systematic review provides an overview of attributes included in studies eliciting stated preferences for CRC screening tests and their relative importance for decision-making.

METHODS

Systematic search (November 2021) for English-language studies published since January 2000 in PubMed, Embase, Web of Science, Biomedical Reference Collection: Corporate Edition, LIVIVO and PsycINFO. DCEs and conjoint analysis ranking or rating tasks on screening eligible populations' preferences for stool testing, sigmoidoscopy, and/or colonoscopy were included. Attributes were extracted and their relative importance was calculated and ranked. Risk of bias (RoB) of included studies was assessed using a modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Study selection and RoB rating were carried out independently by two reviewers. Data were extracted by one reviewer and checked by another one.

RESULTS

A total of 23 publications on 22 studies were included. Overall RoB was rated as serious/critical for 21 studies and as moderate for 2 studies. Main reasons for high RoB were non-random sampling, low response rates, lack of non-responder analyses, and, to a lesser extent, weaknesses in the measurement instrument and data analysis. Extracted attributes (n = 120) referred to procedure-related characteristics (n = 42; 35%), structural characteristics of health care (n = 24; 20%), test characteristics (n = 23; 19%), harms (n = 16; 13%), benefits (n = 13; 11%), and level of evidence (n = 2; 2%). Most important attributes were reduction in CRC mortality (and incidence) (n = 7), test sensitivity (n = 7), out-of-pocket costs (n = 4), procedure (n = 3), and frequency (n = 2).

CONCLUSIONS

Health preference studies on CRC were found to have a high RoB. The composition of choice tasks revealed a lack of attributes on patient-important outcomes (like incidence reduction), while attributes not considered relevant for individual screening decisions (like sensitivity) were frequently used. Future studies eliciting stated preferences in cancer screening should apply the principles of informed decision-making in attribute identification and selection.

A discrete choice model implementing gist-based categorization of alternatives, with applications to patient preferences for cancer screening and treatment

The rational microeconomic decision model is hard-coded into usual econometric specifications such as the Multinomial Logit and Probit models, inter alia. There is a very tight link between utility maximization and the apparatus of welfare theory that underlies economic policy analysis, which creates a tension around the possibility of representing other decision rules. We propose a less restrictive model of choice, built on the concept of gist-based categorization judgments that are assumed to precede (thus, condition) the maximization-driven selection process in decision making. This categorization facilitates decision making by allowing adoption of certain simpler decision rules under appropriate conditions, the drivers of which are endogenously determined. We demonstrate that the proposed model provides better fit than traditional choice models, using cancer screening and treatment choice data from two discrete choice experiments. In addition, we show that the model provides a deeper, more nuanced and insightful perspective on (healthcare) decision making.

Methodology to derive preference for health screening programmes using discrete choice experiments: a scoping review

BACKGROUND

While involving users in healthcare decision-making has become increasingly common and important, there is a lack of knowledge about how to best design community-based health screening programs. Reviews of methods that incorporate discrete choice experiments (DCEs) are scarce, particularly for non-cancer illnesses like cardiovascular disease, diabetes and liver disease. We provide an overview of currently available applications and methods available by using DCEs in health screening programs, for chronic conditions.

METHODS

A scoping review was undertaken, where four electronic databases were searched for key terms to identify eligible DCE studies related to community health screening. We included studies that met a pre-determined criteria, including being published between 2011 and 2021, in English and reported findings on human participants. Data were systematically extracted, tabulated, and summarised in a narrative review.

RESULTS

A total of 27 studies that used a DCE to elicit preferences for cancer (n = 26) and cardiovascular disease screening (n = 1) programmes were included in the final analysis. All studies were assessed for quality, against a list of 13 criteria, with the median score being 9/13 (range 5-12). Across the 27 studies, the majority (80%) had the same overall scores. Two-thirds of included studies reported a sample size calculation, approximately half (13/27) administered the survey completely online and over 75% used the general public as the participating population.

CONCLUSION

Our review has led to highlighting several areas of current practice that can be improved, particularly greater use of sample size calculations, increased use of qualitative methods, better explanation of the chosen experimental design including how choice sets are generated, and methods for analysis.

Choice experiment selection of tourism destinations in a dual process theory framework: The role of decision style and potential to promote deliberation

Models of consumer choice that assume rational decision processes are too simplistic, as they ignore intuitive processes and combinations of intuition and rationality. In dual process theory, System 1 processes are intuitive, fast, require low cognitive effort, and involve autonomous systems, while System 2 processes are deliberative, slower, reflect greater cognitive effort, and involve controlled attention. The dual process framework facilitates understanding of decision processes that may be diverse and complex. Based on response time as an indicator of System 2 use, we fill gaps in the tourism and choice experiment literatures by i) assessing the dimensionality of a decision style scale and its role in predicting System 2 use and ii) assessing whether researcher interventions, such as instructions, can promote System 2 use. The study is based on survey-based choice experiment responses of 483 domestic and international visitors across two Norwegian nature-based tourism destination contexts. Each visitor completed four choice experiment tasks for a total of 1,932 choice occasions. Results indicated diversity in extent of System 2 use. The decision style scale was multidimensional with both the intuitive and rational subscales predicting response time. We encourage inclusion of decision style scales–and specifically multidimensional scales–in future tourism choice and choice experiment applications. Statistically significant coefficients for instructions and unhurriedness suggest potential for researchers to increase System 2 processing in survey tasks. We encourage future use of this intervention, especially when survey tasks are intended to replicate “real world” decisions that rely heavily on System 2 use.

Attributes Used for Cancer Screening Discrete Choice Experiments: A Systematic Review

BACKGROUND

Evidence from discrete choice experiments can be used to enrich understanding of preferences, inform the (re)design of screening programmes and/or improve communication within public campaigns about the benefits and harms of screening. However, reviews of screening discrete choice experiments highlight significant discrepancies between stated choices and real choices, particularly regarding willingness to undergo cancer screening. The identification and selection of attributes and associated levels is a fundamental component of designing a discrete choice experiment. Misspecification or misinterpretation of attributes may lead to non-compensatory behaviours, attribute non-attendance and responses that lack external validity.

OBJECTIVES

We aimed to synthesise evidence on attribute development, alongside an in-depth review of included attributes and methodological challenges, to provide a resource for researchers undertaking future studies in cancer screening.

METHODS

A systematic review was conducted to identify discrete choice experiments estimating preferences towards cancer screening, dated between 1990 and December 2020. Data were synthesised narratively. In-depth analysis of attributes led to classification into four categories: test specific, service delivery, outcomes and monetary. Attribute significance and relative importance were also analysed. The International Society for Pharmacoeconomics and Outcomes Research conjoint analysis checklist was used to assess the quality of reporting.

RESULTS

Forty-nine studies were included at full text. They covered a range of cancer sites: over half (26/49) examined colorectal screening. Most studies elicited general public preferences (34/49). In total, 280 attributes were included, 90% (252/280) of which were significant. Overall, test sensitivity and mortality reduction were most frequently found to be the most important to respondents.

CONCLUSIONS

Improvements in reporting the identification, selection and construction of attributes used within cancer screening discrete choice experiments are needed. This review also highlights the importance of considering the complexity of choice tasks when considering risk information or compound attributes. Patient and public involvement and stakeholder engagement are recommended to optimise understanding of unavoidably complex choice tasks throughout the design process. To ensure quality and maximise comparability across studies, further research is needed to develop a risk-of-bias measure for discrete choice experiments.

Rate and associated factors of refusal to perform immunochemical Faecal Occult Blood Test (iFOBT) among semi-urban communities

The uptake of the immunochemical faecal occult blood test (iFOBT) in many countries with an opportunistic colorectal cancer (CRC) screening programme remains suboptimal. This study aimed to determine the rate, associated factors and reasons of refusal to perform the iFOBT test offered under an opportunistic CRC screening programme in semi-urban communities. This cross-sectional study was conducted among the average-risk individuals living in semi-urban areas, who sought care from public primary care centres across Kedah state, Malaysia. The information regarding the sociodemographic and clinical characteristics of individuals who were offered the iFOBT between January and April 2019, along with their willingness to perform the test, was gathered. The factors associated with the refusal were further explored using the logistic regression analysis. The individuals offered the iFOBT (n = 920) were mainly female (52.4%) and had a mean age of 58.7±10.6 years. The refusal rate of the iFOBT was 32.2%. Patients who did not have hypertension (adjusted OR: 3.33; 95% CI: 2.44, 4.54), did not have CRC symptoms (adjusted OR: 3.15; 95% CI:1.26, 7.89), had the test offered by either medical assistants (adjusted OR: 2.44; 95% CI: 1.71, 3.49) or nurses (adjusted OR: 2.41; 95% CI 1.65, 3.51), did not have diabetes (adjusted OR: 1.99; 95% CI: 1.42, 2.77),and were not active smokers (adjusted OR: 1.74; 95% CI: 1.22, 2.47), were more likely to refuse the iFOBT. The common reasons of refusing the test included "feeling not ready for the test" (21.6%) and "feeling healthy" (14.9%). The iFOBT was refused by one-third of the average-risk individuals from semi-urban communities. The associated factors and reasons of refusal found in this study could guide policymakers in developing targeted interventions to boost the uptake of CRC screening in Malaysia.

Patients Prioritize a Low-volume Bowel Preparation in Colitis-associated Colorectal Cancer Surveillance: A Discrete Choice Experiment

BACKGROUND

Patients with inflammatory bowel disease (IBD) undergo surveillance colonoscopies at fixed intervals to reduce the risk of colorectal cancer (CRC). Taking patients' preferences for determining surveillance strategies into account could improve adherence and patient satisfaction. This study aimed to determine patient preferences for CRC surveillance in IBD.

METHODS

We conducted a web-based, multicenter, discrete choice experiment among adult IBD patients with an indication for surveillance. Individuals were repeatedly asked to choose between 3 hypothetical surveillance scenarios. The choice tasks were based on bowel preparation (0.3-4 L), CRC risk reduction (8% to 1%-6%), and interval (1-10 years). Attribute importance scores, trade-offs, and willingness to participate were calculated using a multinomial logit model. Latent class analysis was used to identify subgroups with similar preferences.

RESULTS

In total, 310 of 386 sent out questionnaires were completed and included in the study. Bowel preparation was prioritized (attribute importance score 40.5%) over surveillance interval and CRC risk reduction (31.1% and 28.4%, respectively). Maximal CRC risk reduction, low-volume bowel preparation (0.3 L laxative with 2 L clear liquid) with 2-year surveillance was the most preferred combination. Three subgroups were identified: a "surveillance avoidant," "CRC risk avoidant," and "surveillance preferring" groups. Membership was correlated with age, educational level, perceived CRC risk, the burden of bowel preparation, and colonoscopies.

CONCLUSIONS

Inflammatory bowel disease patients consider bowel preparation as the most important element in acceptance of CRC surveillance. Heterogeneity in preferences was explained by 3 latent subgroups. These findings may help to develop an individualized endoscopic surveillance strategy in IBD patients.