1 Introduction
The value of the patient perspective in the medical product life cycle has never been more appreciated than it is at the current moment. Patients and patient advocacy groups, regulatory and heath technology assessment (HTA) bodies, and industry leaders are increasingly advocating for the use of information collected from patients to inform product and trial designs, market access, and reimbursement schedules [
1‐
4]. The US Food and Drug Administration has approved guidance on the use of health preferences in marketing authorization [
5]. The European Medicines Agency gave a favorable opinion to a framework on planning and conducting health preference studies [
6], the National Institute for Health and Care Excellence has published a perspective on the use of preference data in HTA decision making [
1], and the CIOMS working group XI published a report emphasizing the importance of including patient perspectives in medical product decision making [
7]. This has resulted in an ever-growing field of researchers who study health preferences and an enormous growth in studies assessing what patients value in their healthcare [
8]. With this interest in health preference assessment, there have also been calls to ensure that the studies are methodologically sound and produce reliable and valid information [
9].
To address these issues, the IMI-PREFER project, a 6-year European public-private partnership, was launched in 2016 to inform on the use of health preference studies for decision making throughout the medical product life cycle [
10]. In 2018, the IMI-PREFER project conducted a survey to identify research priorities based on expert consensus, early literature reviews, stakeholder interviews, and a ranking exercise of research topics and questions [
11]. The most important research priorities identified were related to four high-level concepts: evidentiary standards, assessment of preference heterogeneity, means to minimize patient burden, and means to maximize patient understanding of concepts presented in preference studies. These were used to guide the research questions addressed in ten PREFER case studies that provided evidence to support recommendations on when and how to execute health preference studies [
12‐
22].
Since this initial research call was conducted, the field of preference research has evolved as studies were published related to these topics [
16,
23‐
36]. Thus, the objective of this exploratory study was to reassess what members of the preference research community currently think are research priorities.
4 Discussion
Over the past decades, there has been increased interest in measuring health preferences to aid decision making during drug development. This has generated questions about how to assess health preferences reliably from a variety of different stakeholders (including academic researchers, industry members, consultancies, health authorities, and patient groups). This prioritization exercise was conducted to prioritize research topics for the health preference research community with the goal of increasing acceptance of health preference methods and their results by decision makers in the medical product life cycle. We identified 19 important research topics for future study that would increase acceptance of preference methods and their results by decision makers. Within these 19 topics, there were clear priorities for specific topics.
While all the research topics presented were considered important to study by a majority of the respondents, the most important research topics related to a mix of methodological and applied research topics. Two of the highest priority topics were related to the use of health preference research outside of the individual study population: either for use in other populations or for use in a meta-analysis and predicting preferences. Both of these topics were identified as important in both ranking tasks and were not listed as having been previously studied. Conducting a preference study can be a time- and resource-intensive undertaking, thus the reuse of previous health preferences to inform new or future decision making can help ensure that patient values are considered when a new study is not possible or necessary.
Five topics (
Internal Validity/Data Quality,
Attribute Presentation & Framing,
Method Selection Guidance,
Changing Number of Attributes, and
Educational Materials - Which Material to Enhance?) were listed as important for future research by over half of the respondents, though over 20% of respondents felt that these topics had been researched enough previously. The topic of
Method Selection Guidance was highly rated in the BWS-1 task, indicating that many respondents think it is a top priority despite 34% of respondents thinking it had already been researched adequately. The disparity between ranking these as important topics and thinking that while important it has previously been studied enough may simply be a difference of opinion. However, it may also reflect a lack of awareness of previous work in this area. Recent publications have highlighted decision criteria that can be used to guide method selection [
23,
24], and previous research has been published on internal validity tests and patient comprehension [
25‐
27], attribute presentation and framing [
28‐
31], the number of attributes [
32], and educational materials [
16,
33,
34] thus this finding may reflect a variability in awareness of the contribution of this previous work. As the amount of methodological research available increases, there will be a need to provide consolidated and updated dissemination resources. Examples of these types of resources could be online courses and webinars, seminars, trainings hosted by professional organizations, or catalogs and repositories of published studies.
Survey participants did express an interest in a library of previously developed attributes for targeted areas, for example, oncology outcomes and outcomes frequently seen across diseases. Challenges with an attribute library include reaching a consensus on which attributes to include and the most appropriate attribute definitions, sufficient uptake, and long-term sustainability. One possible model towards an attribute library could be to follow the example of OMERACT [
43], an independent organization that strives to improve endpoint outcomes through a data-driven, iterative consensus process involving relevant stakeholder groups. In addition, an intermediate step towards an attribute library could be the registration of most preference studies in a standardized manner, for example, through the Health Preference Study Technology Registry [
44].
If we compare this study’s results to the previous PREFER prioritization exercise, some trends can be observed [
11]. In the previous prioritization exercise, transferability of preference results both within a patient population and to other populations was highly prioritized. These topics overlap with the current study topics of
Synthesis of Preferences Across Studies and
Transferability Across Populations or Related Diseases, which were more highly prioritized than in the original study, indicating that they remain a topic of interest to stakeholders. The transferability of preferences information is often discussed in research articles [
45‐
48] and is relevant to the transferability of other health economic analyses such as those conducted by HTA organizations [
49]. However, there is no published guidance on how to assess the transferability of preferences or what evidence is needed to support the application of health preference information to new contexts. Additionally, the comparison of different methods for preference elicitation, study of non-discrete choice experiment methods, and the consistency of preference outcomes from different methods were highly prioritized topics in the previous exercise. In the current study, this topic remained an important topic with indications that while additional research has been done in these areas since the first prioritization exercise [
23,
50‐
53], more research would help to understand which method to choose when conducting a preference study. Interestingly, the topic of stability of preferences over time was previously ranked as least important, but in this updated exercise it was considered the second most important research topic.
Not unexpectedly, there were differences in prioritization of health preference research based on stakeholder affiliation. Academic researchers tended to prioritize methodological and/or less studied topics, including transferability and external validity. For other stakeholders, most of them are likely to use preferences for decision making, prioritized applied research topics relating to consistency of practice, including methods selection guidance, internal validity, and synthesis of preferences across studies. Differences in prioritization of research topics most likely reflect the different needs and experience of different stakeholders. Academic researchers prioritized studying the transferability of preferences more than respondents whose primary preference work was done outside of academia. One possible explanation for this could be that academic researchers have more experience organizing, designing, or managing patient preference studies as 76% of respondents identifying as academic reported having this experience compared with 54% of other stakeholders. Another possible explanation is that while it may be more imperative in industry to keep costs for preference studies lower and reduce barriers to their use, industry-sponsored preference studies are frequently conducted to inform specific decisions, and therefore transferability might seem less relevant. In addition, regulators are an important audience for industry-sponsored preference studies, and regulatory agencies have stressed the importance of fit-for-purpose preference studies to inform decision making [
54,
55]. As more evidence is generated around this topic, it may become more prioritized by other stakeholders. To ensure that the needs of a variety of stakeholders are met and to encourage a diversity of perspectives, it remains important to continue cross-sector collaborations.
Lower priority topics were similar across the groups, including questions on revealed preferences, educational materials, and psychological constructs. Lower prioritization of these topics may reflect the perception that these questions are difficult, if not impossible, to answer (Revealed Preferences) or that there are lower levels of familiarity with topics by members of the preference research community (Educational Materials and Psychological Constructs).
A strength of this study was the use of two instruments to rank the topics, allowing for a richer understanding of respondent opinions. By combining the results, we were able to understand why some topics may have been important to some while not being prioritized by others. Another strength of this study was the inclusion of the broader health preference community, including professional society preference research groups and scientific advisors beyond PREFER researchers. This differs from previous prioritization exercises in that it included a broader community. However, this study did have some limitations. One limitation of this study was that the study topics were identified based on experiences with PREFER by researchers involved with PREFER. While participants representing academia, industry, and regulatory agencies provided input, it is possible that a different sample of stakeholders may have identified somewhat different research topics. Further, the survey was sent to professional societies and mailing lists that had existing professional relationships with the study authors. The survey was not publicized outside of these networks and did not attempt to recruit preference researchers not affiliated with these professional societies. The respondents therefore reflect a convenience sample. Another limitation is the experience that the stakeholders reported in generating and using preference information. While none of the stakeholder respondents indicated that they had no experience or were unaware of what health preferences studies were before this survey, 37% of respondents indicated that they had never organized, designed, or managed health preference studies and 46% said they had not yet used the results of preference studies in their work. However, the impact of health preference research are being felt more broadly than by only those who directly conduct and apply this information, so a broader sample likely reflects the actual stakeholder community and the reach of health preference research.
Acknowledgments
The authors are grateful to members of the PREFER Consortium, scientific advisors, and health preference research community, including the International Academy of Health Preference Research and ISPOR Health Preference Research Special Interest Group, for their important contribution in completing this study that allowed the ranking of research priorities. A special acknowledgment to Sander Boxebeld, Dr. Norah Crossnohere, Dr. Ilene Hollin, Dr. Bennett Levitan, Dr. Karin Schölin Bywall, Nicholas Smeele, Dr. Vikas Soekhai, Dr. Chiara Whichello, and Dr. Janine van Til for their assistance in refining the survey.