Making sense of patient priorities: applying discrete choice methods in primary care using 'think aloud' technique

Trade-offs between overall survival and side effects in the treatment of metastatic breast cancer: eliciting preferences of patients with primary and metastatic breast cancer using a discrete choice experiment

OBJECTIVES

There has been a recent proliferation in treatment options for patients with metastatic breast cancer. Such treatments often involve trade-offs between overall survival and side effects. Our study aims to estimate the trade-offs that could be used to inform decision-making at the individual and policy level.

DESIGN

We designed a discrete choice experiment (DCE) to look at preferences for avoiding severity levels of side effects when choosing treatment for metastatic breast cancer. Treatment attributes were: fatigue, nausea, diarrhoea, other side effects (peripheral neuropathy, hand-foot syndrome and mucositis) and urgent hospital admission and overall survival. Responses were analysed using an error component logit model. We estimated the relative importance of attributes and minimum acceptable survival for improvements in side effects.

SETTING

The DCE was completed online by UK residents with self-reported diagnoses of breast cancer.

PARTICIPANTS

105 respondents participated, of which 72 patients had metastatic breast cancer and 33 patients had primary breast cancer.

RESULTS

Overall survival had the largest relative importance, followed by other side effects, diarrhoea, nausea and fatigue. The risk of urgent hospital admission was not significant. While overall survival was the most important attribute, respondents were willing to forgo some absolute probability of overall survival for reductions in all Grade 2 side effects (12.02% for hand-foot syndrome, 11.01% for mucositis, 10.42% for peripheral neuropathy, 6.33% for diarrhoea and 3.62% for nausea). Grade 1 side effects were not significant, suggesting respondents have a general tolerance for them.

CONCLUSIONS

Patients are willing to forgo overall survival to avoid particular severity levels of side effects. Our results have implications for data collected in research studies and can help inform person-centred care and shared decision-making.

Preferences for Physical Examination Service in Community Health Service Center in China: A Discrete Choice Experiment

Objective

Physical examination services play a crucial role in the early detection of diseases, improving the effectiveness of treatment. However, the current physical examination services provided by community health service centers are limited. The objective of this study was to investigate the aspects of physical examination services that are most valued by residents.

Methods

Identify and develop attributes and levels through literature research and expert group interviews. A discrete choice experiment was designed. The main effects design gives rise to 16 choice sets. The 16 choice sets were grouped into 2 blocks, and respondents were randomly assigned to one of the blocks. In each choice set, respondents were asked to choose from two alternatives with an opt-out option. In 2023, the discrete choice experiment was administered in several community health service centers within a China population sample. A mixed logit and a latent class analysis were conducted.

Results

Participants (n = 399) preferred to receive health advice service. The services provided by the basic team with clinical experts are preferred over those provided solely by the basic team. The results indicated a preference for a participant to be serviced by face-to-face or telephone compared with WeChat. Low cost is also preferred. As participants grow older, their preference for face-to-face or telephone-based services increased. As participants' service demand increase, participants more preferred to receive interpretation of physical examination report and follow-up of important abnormal results, participants more preferred to be serviced by basic team with clinical experts or basic team with health manager etc.

Conclusion

We should improve the construction of the service team, optimize the service mode, expand the scope of examination services, reduce the cost of examination services, and meet the needs of residents for physical examination services. More attention should be paid to the needs of elderly and rural residents.

DCE attribute development investigating public policy for the provision of medicinal cannabis

BACKGROUND

Defining attributes and attribute levels for a discrete choice experiment (DCE) poses a significant challenge for practitioners exploring preferences for new or unfamiliar products due to the dearth of available information and limits in stakeholder knowledge. This study outlines a comprehensive process for identifying attributes and levels in a DCE aimed at gauging public preferences for health policies related to medicinal cannabis (MC).

METHODS

A rigorous four-stage attribute development process was utilized and included i) the formulation of a preliminary attribute list from a scoping review and document analysis, ii) reduction of attributes via focus groups, iii) removal of inappropriate attributes using Delphi studies and research team knowledge, and iv) refinement of attribute language based on the feedback from think-aloud interviews.

RESULTS

A base attribute list formed from the scoping review and document analysis served as effective discussion stimuli in focus groups, especially for participants with limited subject knowledge. Structured focus group activities proved more effective than open-ended discussions in engaging naive participants. Delphi studies were found to be overcomplex for expert-led attribute prioritization. Think-aloud interviews during a pilot DCE were essential for assessing attribute language and clarity and understanding participants' decision-making processes.

CONCLUSION

The development of DCE attributes measuring preferences for an unfamiliar health product requires a multi-method approach. Evaluating the outcomes from various methods of attribute development yielded a refined list of attributes that were significant to stakeholders, allowed for meaningful trade-offs, and were presented in language accessible to the target population.

Quantifying the impact of taking medicines for primary prevention: a time-trade off study to elicit direct treatment disutility in the UK

BACKGROUND

Direct treatment disutility (DTD) represents an individual's disutility associated with the inconvenience of taking medicine over a long period of time.

OBJECTIVES

The main aim of this study was to elicit DTD values for taking a statin or a bisphosphonate for primary prevention. A secondary aim was to understand factors which influence DTD values.

METHODS

Design: We used a cross-sectional study consisting of time-trade off exercises embedded within online surveys. Respondents were asked to compare a one-off pill ('Medicine A') assumed to have no inconvenience and a daily pill ('Medicine B') over 10 years (statins) or 5 years (bisphosphonates).Setting: Individuals from National Health Service (NHS) primary care and the general population were surveyed using an online panel company.Participants: Two types of participants were recruited. First, a purposive sample of patients with experience of taking a statin (n=260) or bisphosphonate (n=100) were recruited from an NHS sampling frame. Patients needed to be aged over 30, have experience of taking the medicine of interest and have no diagnosis of dementia or of using dementia drugs. Second, a demographically balanced sample of members of the public were recruited for statins (n=376) and bisphosphonates (n=359).Primary and secondary outcome measures: Primary outcome was mean DTD. Regression analysis explored factors which could influence DTD values.

RESULTS

A total of 879 respondents were included for analysis (514 for statins and 365 for bisphosphonates). The majority of respondents reported a disutility associated with medicine use. Mean DTD for statins was 0.034 and for bisphosphonates 0.067, respectively. Respondent characteristics including age and sex did not influence DTD. Experience of bisphosphonate-use reduced reported disutilities.

CONCLUSIONS

Statins and bisphosphonates have a quantifiable DTD. The size of estimated disutilities suggest they are likely to be important for cost-effectiveness, particularly in individuals at low-risk when treated for primary prevention.

Deciding Between SF-6Dv2 Health States: A Think-Aloud Study of Decision-Making Strategies Used in Discrete Choice Experiments

OBJECTIVE

This study aimed to gain insight into decision-making strategies individuals used when evaluating pairs of SF-6Dv2 health states in discrete choice experiments (DCEs).

METHODS

This qualitative, cross-sectional, noninterventional study asked participants to use a think-aloud approach to compare SF-6Dv2 health states in DCEs. Thematic analysis focused on comprehension and cognitive strategies used to compare health states and make decisions.

RESULTS

Participants (N = 40) used 3 main strategies when completing DCEs: (1) trading, (2) reinterpretation, and (3) relying on previous experience. Trading was the most common strategy, used by everyone at least once, and involved prioritizing key attributes, such as preferring a health state with significant depression but no bodily pain. Reinterpretation was used by 17 participants and involved reconstructing health states by changing underlying assumptions (eg, rationalizing selecting a health state with significant pain because they could take pain medications). Finally, some (n = 13) relied on previous experience when making decisions on some choice tasks. Participants with experience dealing with pain, for instance, prioritized health states with the least impact in this dimension.

CONCLUSIONS

Qualitatively evaluating the decision-making strategies used in DCEs allows researchers to evaluate whether the tasks and attributes are interpreted accurately. The findings from this study add to the understanding of the generation of SF-6Dv2 health utility weights and the validity of these weights (e.g., reinterpreting health states could undermine the validity of DCEs and utility weights), and the overall usefulness of the SF-6Dv2. The methodology described in this study can and should be carried forth in valuing other health utility measures, not just the SF-6Dv2.

Health preference research: An overview for medical radiation sciences

Understanding preferences of key stakeholders including patients, clinicians and policymakers can inform clinical practice, workforce and policy. It also allows health services to evaluate existing clinical practices, policies and procedures. This commentary aims to introduce medical radiation professionals to health preference research by describing commonly used preference methodologies, with a particular focus on discrete choice experiments. Relevant examples of health preference research will be highlighted to demonstrate the application of health preference research in medical radiation sciences.

Patient Preferences for Anxiety and Depression Screening in Cancer Care: A Discrete Choice Experiment

OBJECTIVES

Screening for anxiety and depression in cancer care is recommended, as identification is the first step in managing anxiety and depression. Nevertheless, patient preferences for anxiety and depression screening in cancer care are unknown. The objective of this study was to investigate and identify the aspects of an anxiety and depression screening program cancer patients value most, to inform decision-makers about ways to improve patient uptake and ultimately, the provision of patient-centered care.

METHODS

A discrete choice experiment was designed and implemented within an Australian cancer population sample. Participants were presented with a series of hypothetical screening programs labeled as "screening program 1" and "screening program 2" and were asked to choose their preferred one. The discrete choice experiment was administered using an online survey platform. A mixed logit and a latent class analysis was conducted.

RESULTS

Participants (n = 294) preferred screening to be conducted by a cancer nurse, face-to-face, and at regular intervals (monthly or every 3 months). Participants also preferred follow-up care to be delivered by mental health professionals embedded within the cancer care team. Factors that influenced preferences were the low cost and short waiting times for access to care.

CONCLUSIONS

Cancer patients prefer cancer services with integrated mental healthcare services. To maximize patient uptake, anxiety and depression screening programs should be routinely offered, delivered by oncology healthcare staff in a face-to-face format, and, postscreening, to be care for by mental health professionals embedded within the cancer service.

Publics’ preferences for sharing health data: a discrete choice experiment (Preprint)

Background

Digital technological development in the last 20 years has led to significant growth in digital collection, use, and sharing of health data. To maintain public trust in the digital society and to enable acceptable policy-making in the future, it is important to investigate people’s preferences for sharing digital health data.

Objective

The aim of this study is to elicit the preferences of the public in different Northern European countries (the United Kingdom, Norway, Iceland, and Sweden) for sharing health information in different contexts.

Methods

Respondents in this discrete choice experiment completed several choice tasks, in which they were asked if data sharing in the described hypothetical situation was acceptable to them. Latent class logistic regression models were used to determine attribute-level estimates and heterogeneity in preferences. We calculated the relative importance of the attributes and the predicted acceptability for different contexts in which the data were shared from the estimates.

Results

In the final analysis, we used 37.83% (1967/5199) questionnaires. All attributes influenced the respondents’ willingness to share health information (P<.001). The most important attribute was whether the respondents were informed about their data being shared. The possibility of opting out from sharing data was preferred over the opportunity to consent (opt-in). Four classes were identified in the latent class model, and the average probabilities of belonging were 27% for class 1, 32% for class 2, 23% for class 3, and 18% for class 4. The uptake probability varied between 14% and 85%, depending on the least to most preferred combination of levels.

Conclusions

Respondents from different countries have different preferences for sharing their health data regarding the value of a review process and the reason for their new use. Offering respondents information about the use of their data and the possibility to opt out is the most preferred governance mechanism.

Opening the 'Black Box': An Overview of Methods to Investigate the Decision-Making Process in Choice-Based Surveys

The desire to understand the preferences of patients, healthcare professionals and the public continues to grow. Health valuation studies, often in the form of discrete choice experiments, a choice based survey approach, proliferate as a result. A variety of methods of pre-choice process analysis have been developed to investigate how and why people make their decisions in such experiments and surveys. These techniques have been developed to investigate how people acquire and process information and make choices. These techniques offer the potential to test and improve theories of choice and/or associated empirical models. This paper provides an overview of such methods, with the focus on their use in stated choice-based healthcare studies. The methods reviewed are eye tracking, mouse tracing, brain imaging, deliberation time analysis and think aloud. For each method, we summarise the rationale, implementation, type of results generated and associated challenges, along with a discussion of possible future developments.

Respondent Understanding in Discrete Choice Experiments: A Scoping Review

Introduction

Despite the recognised importance of participant understanding for valid and reliable discrete choice experiment (DCE) results, there has been limited assessment of whether, and how, people understand DCEs, and how ‘understanding’ is conceptualised in DCEs applied to a health context.

Objectives

Our aim was to identify how participant understanding is conceptualised in the DCE literature in a health context. Our research questions addressed how participant understanding is defined, measured, and used.

Methods

Searches were conducted (June 2019) in the MEDLINE, EMBASE, PsychINFO and Econlit databases, as well as hand searching. Search terms were based on previous DCE systematic reviews, with additional understanding keywords used in a proximity-based search strategy. Eligible studies were peer-reviewed journal articles in the field of health, related to DCE or best-worst scaling type 3 (BWS3) studies, and reporting some consideration or assessment of participant understanding. A descriptive analytical approach was used to chart relevant data from each study, including publication year, country, clinical area, subject group, sample size, study design, numbers of attributes, levels and choice sets, definition of understanding, how understanding was tested, results of the understanding tests, and how the information about understanding was used. Each study was categorised based on how understanding was conceptualised and used within the study.

Results

Of 306 potentially eligible articles identified, 31 were excluded based on titles and abstracts, and 200 were excluded on full-text review, resulting in 75 included studies. Three categories of study were identified: applied DCEs (n = 52), pretesting studies (n = 7) and studies of understanding (n = 16). Typically, understanding was defined in relation to either the choice context, such as attribute terminology, or the concept of choosing. Very few studies considered respondents’ engagement as a component of understanding. Understanding was measured primarily through qualitative pretesting, rationality or validity tests included in the survey, and participant self-report, however reporting and use of the results of these methods was inconsistent.

Conclusions

Those conducting or using health DCEs should carefully select, justify, and report the measurement and potential impact of participant understanding in their specific choice context. There remains scope for research into the different components of participant understanding, particularly related to engagement, the impact of participant understanding on DCE validity and reliability, the best measures of understanding, and methods to maximise participant understanding.

Electronic supplementary material

The online version of this article (10.1007/s40271-020-00467-y) contains supplementary material, which is available to authorized users.

Development of a Discrete Choice Experiment (DCE) Questionnaire to Understand Veterans' Preferences for Tobacco Treatment in Primary Care

BACKGROUND

Providers often prescribe counseling and/or medications for tobacco cessation without considering patients' treatment preferences.

OBJECTIVE

The primary aims of this study are to describe (1) the development of a discrete choice experiment (DCE) questionnaire designed to identify the attributes and levels of tobacco treatment that are most important to veterans; and (2) the decision-making process in choosing between hypothetical tobacco treatments.

METHODS

We recruited current smokers who were already scheduled for a primary care appointment within a single Veterans Affairs (VA) healthcare system. Subjects were asked to rate the importance of selected treatment attributes and were interviewed during two rounds of pilot testing of initial DCE instruments. Key attributes and levels of the initial instruments were identified by targeted literature review; the instruments were iteratively revised after each round of pilot testing. Using a 'think aloud' approach, subjects were interviewed while completing DCE choice tasks. Constant comparison techniques were used to characterize the issues raised by subjects. Findings from the cognitive interviews were used to revise the initial DCE instruments.

RESULTS

Most subjects completed the DCE questionnaire without difficulty and considered two or more attributes in choosing between treatments. Two common patterns of decision-making emerged during the cognitive interviews: (1) counting 'pros' and 'cons' of each treatment alternative; and (2) using a 'rule-out' strategy to eliminate a given treatment choice if it included an undesirable attribute. Subjects routinely discounted the importance of certain attributes and, in a few cases, focused primarily on a single 'must-have' attribute.

CONCLUSION

Cognitive interviews provide valuable insights into the comprehension and interpretation of DCE attributes, the decision processes used by veterans during completion of choice tasks, and underlying reasons for non'-compensatory decision-making.

"I Was Trying to Do the Maths": Exploring the Impact of Risk Communication in Discrete Choice Experiments

BACKGROUND

Risk is increasingly used as an attribute in discrete choice experiments (DCEs). However, risk and probabilities are complex concepts that can be open to misinterpretation, potentially undermining the robustness of DCEs as a valuation method. This study aimed to understand how respondents made benefit-risk trade-offs in a DCE and if these were affected by the communication of the risk attributes.

METHODS

Female members of the public were recruited via local advertisements to participate in think-aloud interviews when completing a DCE eliciting their preferences for a hypothetical breast screening programme described by three attributes: probability of detecting a cancer; risk of unnecessary follow-up; and cost of screening. Women were randomised to receive risk information as either (1) percentages or (2) percentages and icon arrays. Interviews were digitally recorded then transcribed to generate qualitative data for thematic analysis.

RESULTS

Nineteen women completed the interviews (icon arrays n = 9; percentages n = 10). Analysis revealed four key themes where women made references to (1) the nature of the task; (2) their feelings; (3) their experiences, for instance making analogies to similar risks; and (4) economic phenomena such as opportunity costs and discounting.

CONCLUSION

Most women completed the DCE in line with economic theory; however, violations were identified. Women appeared to visualise risk whether they received icon arrays or percentages only. Providing clear instructions and graphics to aid interpretation of risk and qualitative piloting to verify understanding is recommended. Further investigation is required to determine if the process of verbalising thoughts changes the behaviour of respondents.

Research participants' preferences for receiving genetic risk information: a discrete choice experiment

PURPOSE

This study aims to determine research participants' preferences for receiving genetic risk information when participating in a scientific study that uses genome sequencing.

METHODS

A discrete choice experiment questionnaire was sent to 650 research participants (response rate 60.5%). Four attributes were selected for the questionnaire: type of disease, disease penetrance probability, preventive opportunity, and effectiveness of the preventive measure. Panel mixed logit models were used to determine attribute level estimates and the heterogeneity in preferences. Relative importance of the attribute and the predicted uptake for different information scenarios were calculated from the estimates. In addition, this study estimates predicted uptake for receiving genetic risk information in different scenarios.

RESULTS

All characteristics influenced research participants' willingness to receive genetic risk information. The most important characteristic was the effectiveness of the preventive opportunity. Predicted uptake ranged between 28% and 98% depending on what preventive opportunities and levels of effectiveness were presented.

CONCLUSION

Information about an effective preventive measure was most important for participants. They valued that attribute twice as much as the other attributes. Therefore, when there is an effective preventive measure, risk communication can be less concerned with the magnitude of the probability of developing disease.

Discrete choice experiments of pharmacy services: a systematic review

Background Two previous systematic reviews have summarised the application of discrete choice experiments to value preferences for pharmacy services. These reviews identified a total of twelve studies and described how discrete choice experiments have been used to value pharmacy services but did not describe or discuss the application of methods used in the design or analysis. Aims (1) To update the most recent systematic review and critically appraise current discrete choice experiments of pharmacy services in line with published reporting criteria and; (2) To provide an overview of key methodological developments in the design and analysis of discrete choice experiments. Methods The review used a comprehensive strategy to identify eligible studies (published between 1990 and 2015) by searching electronic databases for key terms related to discrete choice and best-worst scaling (BWS) experiments. All healthcare choice experiments were then hand-searched for key terms relating to pharmacy. Data were extracted using a published checklist. Results A total of 17 discrete choice experiments eliciting preferences for pharmacy services were identified for inclusion in the review. No BWS studies were identified. The studies elicited preferences from a variety of populations (pharmacists, patients, students) for a range of pharmacy services. Most studies were from a United Kingdom setting, although examples from Europe, Australia and North America were also identified. Discrete choice experiments for pharmacy services tended to include more attributes than non-pharmacy choice experiments. Few studies reported the use of qualitative research methods in the design and interpretation of the experiments (n = 9) or use of new methods of analysis to identify and quantify preference and scale heterogeneity (n = 4). No studies reported the use of Bayesian methods in their experimental design. Conclusion Incorporating more sophisticated methods in the design of pharmacy-related discrete choice experiments could help researchers produce more efficient experiments which are better suited to valuing complex pharmacy services. Pharmacy-related discrete choice experiments could also benefit from more sophisticated analytical techniques such as investigations into scale and preference heterogeneity. Employing these sophisticated methods for both design and analysis could extend the usefulness of discrete choice experiments to inform health and pharmacy policy.

The Role of Qualitative Research Methods in Discrete Choice Experiments

Background. The use of qualitative research (QR) methods is recommended as good practice in discrete choice experiments (DCEs). This study investigated the use and reporting of QR to inform the design and/or interpretation of healthcare-related DCEs and explored the perceived usefulness of such methods. Methods. DCEs were identified from a systematic search of the MEDLINE database. Studies were classified by the quantity of QR reported (none, basic, or extensive). Authors (n = 91) of papers reporting the use of QR were invited to complete an online survey eliciting their views about using the methods. Results. A total of 254 healthcare DCEs were included in the review; of these, 111 (44%) did not report using any qualitative methods; 114 (45%) reported “basic” information; and 29 (11%) reported or cited “extensive” use of qualitative methods. Studies reporting the use of qualitative methods used them to select attributes and/or levels (n = 95; 66%) and/or pilot the DCE survey (n = 26; 18%). Popular qualitative methods included focus groups (n = 63; 44%) and interviews (n = 109; 76%). Forty-four studies (31%) reported the analytical approach, with content (n = 10; 7%) and framework analysis (n = 5; 4%) most commonly reported. The survey identified that all responding authors (n = 50; 100%) found that qualitative methods added value to their DCE study, but many (n = 22; 44%) reported that journals were uninterested in the reporting of QR results. Conclusions. Despite recommendations that QR methods be used alongside DCEs, the use of QR methods is not consistently reported. The lack of reporting risks the inference that QR methods are of little use in DCE research, contradicting practitioners’ assessments. Explicit guidelines would enable more clarity and consistency in reporting, and journals should facilitate such reporting via online supplementary materials.

Effectiveness and acceptability of parental financial incentives and quasi-mandatory schemes for increasing uptake of vaccinations in preschool children: systematic review, qualitative study and discrete choice experiment

BACKGROUND

Uptake of preschool vaccinations is less than optimal. Financial incentives and quasi-mandatory policies (restricting access to child care or educational settings to fully vaccinated children) have been used to increase uptake internationally, but not in the UK.

OBJECTIVE

To provide evidence on the effectiveness, acceptability and economic costs and consequences of parental financial incentives and quasi-mandatory schemes for increasing the uptake of preschool vaccinations.

DESIGN

Systematic review, qualitative study and discrete choice experiment (DCE) with questionnaire.

SETTING

Community, health and education settings in England.

PARTICIPANTS

Qualitative study - parents and carers of preschool children, health and educational professionals. DCE - parents and carers of preschool children identified as 'at high risk' and 'not at high risk' of incompletely vaccinating their children.

DATA SOURCES

Qualitative study - focus groups and individual interviews. DCE - online questionnaire.

REVIEW METHODS

The review included studies exploring the effectiveness, acceptability or economic costs and consequences of interventions that offered contingent rewards or penalties with real material value for preschool vaccinations, or quasi-mandatory schemes that restricted access to 'universal' services, compared with usual care or no intervention. Electronic database, reference and citation searches were conducted.

RESULTS

Systematic review - there was insufficient evidence to conclude that the interventions considered are effective. There was some evidence that the quasi-mandatory interventions were acceptable. There was insufficient evidence to draw conclusions on economic costs and consequences. Qualitative study - there was little appetite for parental financial incentives. Quasi-mandatory schemes were more acceptable. Optimising current services was consistently preferred to the interventions proposed. DCE and questionnaire - universal parental financial incentives were preferred to quasi-mandatory interventions, which were preferred to targeted incentives. Those reporting that they would need an incentive to vaccinate their children completely required around £110. Those who did not felt that the maximum acceptable incentive was around £70.

LIMITATIONS

Systematic review - a number of relevant studies were excluded as they did not meet the study design inclusion criteria. Qualitative study - few partially and non-vaccinating parents were recruited. DCE and questionnaire - data were from a convenience sample.

CONCLUSIONS

There is little current evidence on the effectiveness or economic costs and consequences of parental financial incentives and quasi-mandatory interventions for preschool vaccinations. Universal incentives are likely to be more acceptable than targeted ones. Preferences concerning incentives versus quasi-mandatory interventions may depend on the context in which these are elicited.

FUTURE WORK

Further evidence is required on (i) the effectiveness and optimal configuration of parental financial incentive and quasi-mandatory interventions for preschool vaccinations - if effectiveness is confirmed, further evidence is required on how to communicate this to stakeholders and the impact on acceptability; and (ii) the acceptability of parental financial incentive and quasi-mandatory interventions for preschool vaccinations to members of the population who are not parents of preschool children or relevant health professionals. Further consideration should be given to (i) incorporating reasons for non-vaccination into new interventions for promoting vaccination uptake; and (ii) how existing services can be optimised.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012003192.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Exploring how individuals complete the choice tasks in a discrete choice experiment: an interview study

Background

To be able to make valid inferences on stated preference data from a Discrete Choice Experiment (DCE) it is essential that researchers know if participants were actively involved, understood and interpreted the provided information correctly and whether they used complex decision strategies to make their choices and thereby acted in accordance with the continuity axiom.

Methods

During structured interviews, we explored how 70 participants evaluated and completed four discrete choice tasks aloud. Hereafter, additional questions were asked to further explore if participants understood the information that was provided to them and whether they used complex decision strategies (continuity axiom) when making their choices. Two existing DCE questionnaires on rotavirus vaccination and prostate cancer-screening served as case studies.

Results

A large proportion of the participants was not able to repeat the exact definition of the risk attributes as explained to them in the introduction of the questionnaire. The majority of the participants preferred more optimal over less optimal risk attribute levels. Most participants (66 %) mentioned three or more attributes when motivating their decisions, thereby acting in accordance with the continuity axiom. However, 16 out of 70 participants continuously mentioned less than three attributes when motivating their decision. Lower educated and less literate participants tended to mention less than three attributes when motivating their decision and used trading off between attributes less often as a decision-making strategy.

Conclusion

The majority of the participants seemed to have understood the provided information about the choice tasks, the attributes, and the levels. They used complex decision strategies (continuity axiom) and are therefore capable to adequately complete a DCE. However, based on the participants’ age, educational level and health literacy additional, actions should be undertaken to ensure that participants understand the choice tasks and complete the DCE as presumed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-016-0140-4) contains supplementary material, which is available to authorized users.

Developing attributes for discrete choice experiments in health: a systematic literature review and case study of alcohol misuse interventions

Discrete choice experiments (DCEs) become increasingly popular to value outcomes for health economic studies and gradually gain acceptance as an input into policy decisions. Developing attributes is a key aspect for the design of DCEs, as their results may misguide decision-makers if they are based on an inappropriate set of attributes. However, the area lacks guidance, and current health-related DCE studies vary considerably in their methods of attribute development, with the consequent danger of providing an unreliable input for policy decisions. The aim of this article is to inform the progress toward a more systematic approach to attribute development for DCE studies in health. A systematic review of the published health-related DCE literature was conducted to lay the foundations for a generic framework which was tested in a case study of alcohol misuse interventions. Four stages of a general attribute development process emerged: (i) raw data collection; (ii) data reduction; (iii) removing inappropriate attributes; and (iv) wording. The case study compared and contrasted a qualitative and mixed-methods approach for the development of attributes for DCEs in the area of alcohol misuse interventions. This article provides a reference point for the design of future DCE experiments in health.

The effect of including an opt-out option in discrete choice experiments

Objective

to determine to what extent the inclusion of an opt-out option in a DCE may have an effect on choice behaviour and therefore might influence the attribute level estimates, the relative importance of the attributes and calculated trade-offs.

Methods

781 Dutch Type 2 Diabetes Mellitus patients completed a questionnaire containing nine choice tasks with an opt-out option and nice forced choice tasks. Mixed-logit models were used to estimate the relative importance of the five lifestyle program related attributes that were included. Willingness to pay (WTP) values were calculated and it was tested whether results differed between respondents who answered the choice tasks with an opt-out option in the first or second part of the questionnaire.

Results

21.4% of the respondents always opted out. Respondents who were given the opt-out option in the first part of the questionnaire as well as lower educated respondents significantly more often opted out. For both the forced and unforced choice model, different attributes showed significant estimates, the relative importance of the attributes was equal. However, due to differences in relative importance weights, the WTP values for the PA schedule differed significantly between both datasets.

Conclusions

Results show differences in opting out based on the location of the opt-out option and respondents' educational level; this resulted in small differences between the forced and unforced choice model. Since respondents seem to learn from answering forced choice tasks, a dual response design might result in higher data quality compared to offering a direct opt-out option. Future research should empirically explore how choice sets should be presented to make them as easy and less complex as possible in order to reduce the proportion of respondents that opts-out due to choice task complexity. Moreover, future research should debrief respondents to examine the reasons for choosing the opt-out alternative.

A think aloud study comparing the validity and acceptability of discrete choice and best worst scaling methods

Objectives

This study provides insights into the validity and acceptability of Discrete Choice Experiment (DCE) and profile-case Best Worst Scaling (BWS) methods for eliciting preferences for health care in a priority-setting context.

Methods

An adult sample (N = 24) undertook a traditional DCE and a BWS choice task as part of a wider survey on Health Technology Assessment decision criteria. A ‘think aloud’ protocol was applied, whereby participants verbalized their thinking while making choices. Internal validity and acceptability were assessed through a thematic analysis of the decision-making process emerging from the qualitative data and a repeated choice task.

Results

A thematic analysis of the decision-making process demonstrated clear evidence of ‘trading’ between multiple attribute/levels for the DCE, and to a lesser extent for the BWS task. Limited evidence consistent with a sequential decision-making model was observed for the BWS task. For the BWS task, some participants found choosing the worst attribute/level conceptually challenging. A desire to provide a complete ranking from best to worst was observed. The majority (18,75%) of participants indicated a preference for DCE, as they felt this enabled comparison of alternative full profiles. Those preferring BWS were averse to choosing an undesirable characteristic that was part of a ‘package’, or perceived BWS to be less ethically conflicting or burdensome. In a repeated choice task, more participants were consistent for the DCE (22,92%) than BWS (10,42%) (p = 0.002).

Conclusions

This study supports the validity and acceptability of the traditional DCE format. Findings relating to the application of BWS profile methods are less definitive. Research avenues to further clarify the comparative merits of these preference elicitation methods are identified.

Bristol girls dance project feasibility study: using a pilot economic evaluation to inform design of a full trial

BACKGROUND

There is currently little guidance for pilot trial economic evaluation where health outcomes and costs are influenced by a range of wider determinants and factors.

OBJECTIVES

This article presents the findings of a pilot economic evaluation study running alongside the Bristol Girls Dance Project (BGDP) feasibility study.

DESIGN

3-arm, cluster randomised, controlled pilot trial and economic evaluation. 7 schools (n=210) from the Bristol and greater Bristol area, UK were randomly allocated to the intervention arm 3 schools (n=90) and the control arm 4 schools (n=120).

INTERVENTION

Girls aged 11-12 years with parental consent were provided with two, 90 min dance sessions per week for 9 weeks at school facilities.

ECONOMIC OUTCOME MEASURES

Programme costs and girls' preferences for attributes of dance and preferences for competing leisure time activities were measured.

RESULTS

The mainstream average cost of the BGDP programme (not including research, control and dance teacher training costs) per school was $2126.40, £1329 and €1555 and per participant was $70.90, £44.31 and €51.84 in 2010-2011 prices. Discrete choice experiment (DCE) methods are acceptable to girls of this age indicating time available for other leisure activities on dance class days is the attribute girls valued most and 2 h leisure time remaining preferred to 3 h.

CONCLUSIONS

This pilot study indicates that providing full cost data for a future trial of the BGDP programme is feasible and practical. There is no evidence from preference data to support adjustment to intervention design. A future economic evaluation is likely to be successful utilising the resource use checklist developed. The importance of categorising separately resources used to develop, prepare, deliver and maintain the programme to estimate mainstream costs accurately is demonstrated.

What determines patient preferences for treating low risk basal cell carcinoma when comparing surgery vs imiquimod? A discrete choice experiment survey from the SINS trial

Background

The SINS trial (Controlled Clinical Trials ISRCTN48755084; Eudract No. 2004-004506-24) is a randomised controlled trial evaluating long term success of excisional surgery vs. imiquimod 5% cream for low risk nodular and superficial basal cell carcinoma (BCC). The trial included a discrete choice experiment questionnaire to explore patient preferences of a cream versus surgery for the treatment of their skin cancer.

Methods

The self-completed questionnaire was administered at baseline to 183 participants, measuring patients’ strength of preferences when choosing either alternative ‘surgery’ or ‘imiquimod cream’ instead of a fixed ‘current situation’ option (of surgical excision as standard practice in UK). The treatments were described according to: cost, chance of complete clearance, side effects and appearance. Participants had to choose between various scenarios. Analysis was performed using a mixed logit model, which took into account the impact of previous BCC treatment and sample preference variability.

Results

The analysis showed that respondents preferred ‘imiquimod cream’ to their ‘current situation’ or ‘surgery’, regardless of previous experience of BCC symptoms and treatment. Respondents were more likely to be worried about their cosmetic outcomes and side effects they might experience over and above their chance of clearance and cost. Those with no experience of surgery (compared with experience) valued more the choice of ‘imiquimod cream’ (£1013 vs £781). All treatment characteristics were significant determinants of treatment choice, and there was significant variability in the population preferences for all of them.

Conclusions

Patients with BCC valued more ‘imiquimod cream’ than alternative ‘surgery’ options, and all treatment characteristics were important for their choice of care. Understanding how people with a BCC value alternative interventions may better inform the development of health care interventions.

Willingness to participate in a lifestyle intervention program of patients with type 2 diabetes mellitus: a conjoint analysis

BACKGROUND

Several studies suggest that lifestyle interventions can be effective for people with, or at risk for, diabetes. The participation in lifestyle interventions is generally low. Financial incentives may encourage participation in lifestyle intervention programs.

OBJECTIVE

The main aim of this exploratory analysis is to study empirically potential effects of financial incentives on diabetes patients' willingness to participate in lifestyle interventions. One financial incentive is negative ("copayment") and the other incentive is positive ("bonus"). The key part of this research is to contrast both incentives. The second aim is to investigate the factors that influence participation in a lifestyle intervention program.

METHODS

Conjoint analysis techniques were used to empirically identify factors that influence willingness to participate in a lifestyle intervention. For this purpose diabetic patients received a questionnaire with descriptions of various forms of hypothetical lifestyle interventions. They were asked if they would be willing to participate in these hypothetical programs.

RESULTS

In total, 174 observations were rated by 46 respondents. Analysis showed that money was an important factor independently associated with respondents' willingness to participate. Receiving a bonus seemed to be associated with a higher willingness to participate, but having to pay was negatively associated with participation in the lifestyle intervention.

CONCLUSION

Conjoint analysis results suggest that financial considerations may influence willingness to participate in lifestyle intervention programs. Financial disincentives in the form of copayments might discourage participation. Although the positive impact of bonuses is smaller than the negative impact of copayments, bonuses could still be used to encourage willingness to participate.

What outcomes are important to patients with long term conditions? A discrete choice experiment

OBJECTIVE

To assess how much patients with long-term conditions value self-efficacy (i.e., confidence in their ability to manage their condition) compared with other health outcomes, including measures of quality of life, and process outcomes including access to General Practitioners.

METHODS

Discrete Choice Experiment (DCE) set in UK community settings.

PARTICIPANTS

367 patients (mean age 57.5) living in the community with a wide range of self-defined long-term conditions.

MAIN OUTCOME MEASURES

The relative value that individuals place on four specific outcomes, namely, self-efficacy, Health Related Quality of Life (HRQoL), access to General Practitioners, and level of isolation.

RESULTS

Most responders completed their questionnaire in a consistent manner. Most valuations of outcomes were in the expected direction and were statistically significant. A substantial minority of responders exhibited counter-intuitive preferences. The existence of a significant constant in all models raised concerns about model misspecification. Nevertheless, all models showed that participants were willing to trade substantial reductions in their HRQoL for improvements in their self-efficacy.

CONCLUSIONS

The majority of patients with chronic conditions were able to complete the DCE questionnaires. However, the existence of counter-intuitive preferences and evidence of model misspecification require further investigation. These issues are largely overlooked in the health economics literature. Self-efficacy is an important outcome for this group and is not included explicitly in conventional HRQoL measures. This is potentially important where decisions are made on the basis of cost-effectiveness using Quality Adjusted Life Years as the metric. Exclusion of these outcomes may lead to the cost-effectiveness of these interventions being understated.

What patients want from primary care consultations: a discrete choice experiment to identify patients' priorities

PURPOSE

The consultation is fundamental to the delivery of primary care, but different ways of organizing consultations may lead to different patient experiences in terms of access, continuity, technical quality of care, and communication. Patients' priorities for these different issues need to be understood, but the optimal methods for assessing priorities are unclear. This study used a discrete choice experiment to assess patients' priorities.

METHODS

We surveyed patients from 6 family practices in England. The patients chose between primary care consultations differing in attributes such as ease of access (wait for an appointment), choice (flexibility of appointment times), continuity (physician's knowledge of the patient), technical quality (thoroughness of physical examination), and multiple aspects of patient-centered care (interest in patient's ideas, inquiry about patient's social and emotional well-being, and involvement of patient in decision making). We used probit models to assess the relative priority patients placed on different attributes and to estimate how much they were willing to pay for them.

RESULTS

Analyses were based on responses from 1,193 patients (a 53% response rate). Overall, patients were willing to pay the most for a thorough physical examination ($40.87). The next most valued attributes of care were seeing a physician who knew them well ($12.18), seeing a physician with a friendly manner ($8.50), having a reduction in waiting time of 1 day ($7.22), and having flexibility of appointment times ($6.71). Patients placed similar value on the different aspects of patient-centered care ($12.06-$14.82). Responses were influenced by the scenario in which the decision was made (minor physical problem vs urgent physical problem vs ambiguous physical or psychological problem) and by patients' demographic characteristics.

CONCLUSIONS

Although patient-centered care is important to patients, they may place higher priority on the technical quality of care and continuity of care. Discrete choice experiments may be a useful method for assessing patients' priorities in health care.