Something Is Better Than Nothing: The Value of Active Intervention in Stated Preferences for Treatments to Delay Onset of Alzheimer's Disease Symptoms

What Can Discrete-Choice Experiments Tell Us about Patient Preferences? An Introduction to Quantitative Analysis of Choice Data

This paper provides an introduction to statistical analysis of choice data using example data from a simple discrete-choice experiment (DCE). It describes the layout of the analysis dataset, types of variables contained in the dataset, and how to identify response patterns in the data indicating data quality. Model-specification options include linear models with continuous attribute levels and non-linear continuous and categorical attribute levels. Advantages and disadvantages of conditional logit, mixed logit, and latent-class analysis are discussed and illustrated using the example DCE data. Readers are provided with links to various software programs for analyzing choice data. References are provided on topics for which there currently is limited consensus and on more advanced techniques to guide readers interested in exploring choice-modeling challenges in greater depth. Supplementary materials include the simulated example data used to illustrate modeling approaches, together with R and Matlab code to reproduce the estimates shown.

Exploring the Factors that Drive Clinical Negligence Claims: Stated Preferences of Those Who Have Experienced Unintended Harm

BACKGROUND

Better understanding of the factors that influence patients to make a financial claim for compensation is required to inform policy decisions. This study aimed to assess the relative importance of factors that influence those who have experienced a patient safety incident (PSI) to make a claim for compensation.

METHOD

Participants completed an online discrete choice experiment (DCE) involving 10 single profile tasks where they chose whether or not to file a claim. DCE data were modelled using logistic, mixed logit and latent class regressions; scenario analyses, external validity, and willingness to accept were also conducted.

RESULTS

A total of 1029 participants in the United Kingdom responded to the survey. An appropriate apology and a satisfactory investigation reduced the likelihood of claiming. Respondents were more likely to claim if they could hold those responsible accountable, if the process was simple and straightforward, if the compensation amount was higher, if the likelihood of compensation was high or uncertain, if the time to receive a decision was quicker, and if they used the government compensation scheme. Men are more likely to claim for low impact PSIs.

DISCUSSION AND CONCLUSIONS

The actions taken by the health service after a PSI, and people's perceptions about the probability of success and the size of potential reward, can influence whether a claim is made. Results show the importance of giving an appropriate apology and conducting a satisfactory investigation. This stresses the importance around how patients are treated after a PSI in influencing the clinical negligence claims that are made.

Can the General Public Be a Proxy for an "At-Risk" Group in a Patient Preference Study? A Disease Prevention Example in Rheumatoid Arthritis

BACKGROUND

When selecting samples for patient preference studies, it may be difficult or impractical to recruit participants who are eligible for a particular treatment decision. However, a general public sample may not be an appropriate proxy.

OBJECTIVE

This study compares preferences for rheumatoid arthritis (RA) preventive treatments between members of the general public and first-degree relatives (FDRs) of confirmed RA patients to assess whether a sample of the general public can be used as a proxy for FDRs.

METHODS

Participants were asked to imagine they were experiencing arthralgia and had screening tests indicating a 60% chance of developing RA within 2 yrs. Using a discrete choice experiment, participants were offered a series of choices between no treatment and 2 unlabeled hypothetical treatments to reduce the risk of RA. To assess data quality, time to complete survey sections and comprehension questions were assessed. A random parameter logit model was used to obtain attribute-level estimates, which were used to calculate relative importance, maximum acceptable risk (MAR), and market shares of hypothetical preventive treatments.

RESULTS

The FDR sample (n = 298) spent more time completing the survey and performed better on comprehension questions compared with the general public sample (n = 982). The relative importance ranking was similar between the general public and FDR participant samples; however, other relative preference measures involving weights including MARs and market share differed between groups, with FDRs having numerically higher MARs.

CONCLUSION

In the context of RA prevention, the general public (average risk) may be a reasonable proxy for a more at-risk sample (FDRs) for overall relative importance ranking but not weights. The rationale for a proxy sample should be clearly justified.

HIGHLIGHTS

Participants from the general public were compared to first-degree relatives on their preferences for rheumatoid arthritis (RA) preventive treatments using a discrete choice experiment.Preferences were similar between groups in terms of the most important and least important attributes of preventive treatments, with effectiveness being the most important attribute. However, relative weights differed.Attention to the survey and predicted market shares of hypothetical RA preventive treatments differed between the general public and first-degree relatives.The general public may be a reasonable proxy for an at-risk group for patient preferences ranks but not weights in the disease prevention context; however, care should be taken in sample selection for patient preference studies when choosing nonpatients.

How healthy participants value additional diagnostic testing with amyloid-PET in patients diagnosed with mild cognitive impairment - a bidding game experiment

BACKGROUND

To estimate the perceived value of additional testing with amyloid-PET in Euros in healthy participants acting as analogue patients with mild cognitive impairment (MCI).

METHODS

One thousand four hundred thirty-one healthy participants acting as analogue MCI patients (mean age 65 ± 8, 929 (75%) female) were recruited via the Dutch Brain Research Registry. Participants were asked to identify with a presented case (video vignette) of an MCI patient and asked whether they would prefer additional diagnostic testing with amyloid PET in this situation. If yes, respondents were asked how much they would be willing to pay for additional diagnostic testing. Monetary value was elicited via a bidding game in which participants were randomized over three conditions: (A) additional testing results in better patient management, (B) Same as condition A and a delay in institutionalization of 3 months, and (C) same as A and a delay in institutionalization of 6 months. Participants who were not willing to take a test were compared with participants who were willing to take a test using logit models. The highest monetary value per condition was analyzed using random-parameter mixed models.

RESULTS

The vast majority of participants acting as analogue MCI patients (87% (n = 1238)) preferred additional testing with amyloid PET. Participants who were not interested were more often female (OR = 1.61 95% CI [1.09-2.40]) and expressed fewer worries to get AD (OR = 0.64 [0.47-0.87]). The median "a priori" (i.e., before randomization) monetary value of additional diagnostic testing was €1500 (IQR 500-1500). If an additional amyloid PET resulted in better patient management (not further specified; condition A), participants were willing to pay a median price of €2000 (IQR = 1000-3500). Participants were willing to pay significantly more than condition A (better patient management) if amyloid-PET testing additionally resulted in a delay in institutionalization of 3 months (€530 [255-805] on top of €2000, condition B) or 6 months (€596 [187-1005] on top of €2000, condition C).

CONCLUSIONS

Members of the general population acting as MCI patients are willing to pay a substantial amount of money for amyloid-PET and this increases when diagnostic testing leads to better patient management and the prospect to live longer at home.

Differences between physician and patient preferences for cancer treatments: a systematic review

BACKGROUND

Shared decision-making is useful to facilitate cancer treatment decisions. However, it is difficult to make treatment decisions when physician and patient preferences are different. This review aimed to summarize and compare the preferences for cancer treatments between physicians and patients.

METHODS

A systematic literature search was conducted on PubMed, Embase, PsycINFO, CINAHL and Scopus. Studies elicited and compared preferences for cancer treatments between physicians and patients were included. Information about the study design and preference measuring attributes or questions were extracted. The available relative rank of every attribute in discrete choice experiment (DCE) studies and answers to preference measuring questions in non-DCE studies were summarized followed by a narrative synthesis to reflect the preference differences.

RESULTS

Of 12,959 studies identified, 8290 were included in the title and abstract screening and 48 were included in the full text screening. Included 37 studies measured the preferences from six treatment-related aspects: health benefit, adverse effects, treatment process, cost, impact on quality of life, and provider qualification. The trade-off between health benefit and adverse effects was the main focus of the included studies. DCE studies showed patients gave a higher rank on health benefit and treatment process, while physicians gave a higher rank on adverse effects. Non-DCE studies suggested that patients were willing to take a higher risk of adverse effects or lower health benefit than physicians when accepting a treatment.

CONCLUSIONS

Physicians and patients had important preference differences for cancer treatment. More sufficient communication is needed in cancer treatment decision-making.

Experiences of and recommendations on clinical trial design in Alzheimer's disease from the participant's point of view: a mixed-methods study in two clinical trial centers in the Netherlands

INTRODUCTION

In the context of the development of pharmaceutical interventions, expectations and experiences of participants are essential. Their insights may be particularly helpful to address the challenges of recruiting and retaining participants for Alzheimer's disease (AD) clinical trials. We examined clinical trial participants' experiences to optimize trial design in Alzheimer's disease (AD).

METHOD

In this mixed-methods study, we included adults who participated in sponsor-initiated AD trials at Brain Research Center, a clinical trial organization in the Netherlands. Participants (N = 71, age 69 ± 6.5, 54%F, 19 cognitively normal (CN), 19 mild cognitive impairment (MCI), and 33 AD dementia) first completed an online survey. Diagnostic group differences were investigated using chi-square tests or one-way ANOVAs. Next, a subsample (N = 12; 8 = CN, 4 = MCI) participated in focus groups to gain in-depth insight into their opinions on optimizing trial design from a participants' point of view. Audio recordings from focus group interviews were transcribed verbatim and analyzed by thematic content analysis by two independent researchers.

RESULTS

Most reported motives for enrolment included "to benefit future generations" (89%), followed by "for science" (66%) and "better monitoring" (42%). Frequent suggestions for increasing willingness to participate included a smaller chance to receive placebo (n = 38, 54%), shorter travel times (n = 27, 38%), and sharing individual results of different assessments (n = 57, 80%), as well as receiving trial results (n = 52, 73). Highest visual analogue burden scores (0-100) were found for the lumbar puncture (M = 47.2, SD = 38.2) and cognitive assessments (M = 27.2, SD = 25.7). Results did not differ between diagnostic groups, nor between patient and caregiver participants (all p-values>.05). Two additional themes emerged from the focus groups: "trial design," such as follow-up visit(s) after participating, and "trial center," including the relevance of a professional and empathic staff.

CONCLUSION

Relevant factors include expectation management and careful planning of high-burden assessments, provision of individual feedback, and prioritizing professionalism and empathy throughout conduct of the trial. Our findings provide insight into participants' priorities to increase willingness to participate and can be used to optimize trial success.

Design of a Non-Interventional Study to Assess Neurologists' Perspectives and Pharmacological Treatment Decisions in Early Alzheimer's Disease

INTRODUCTION

The current therapeutic landscape of Alzheimer's disease (AD) is evolving rapidly. Our treatment options include new anti-amyloid-β protein disease-modifying therapies (DMTs) that decrease cognitive decline in patients with early AD (prodromal and mild AD dementia). Despite these advances, we have limited information on how neurologists would apply the results of recent DMT trials to make treatment decisions. Our goal is to identify factors associated with the use of new AD DMTs among neurologists applying concepts from behavioral economics.

METHODS

This non-interventional, cross-sectional, web-based study will assess 400 neurologists with expertise in AD from across Spain. Participants will start by completing demographic information, practice settings, and a behavioral battery to address their tolerance to uncertainty and risk preferences. Participants will then be presented with 10 simulated case scenarios or vignettes of common encounters in patients with early AD to evaluate treatment initiation with anti-amyloid-β DMTs (e.g., aducanumab, lecanemab, etc.). The primary outcomes will be therapeutic inertia and suboptimal decisions. Discrete choice experiments will be used to determine the weight of factors influencing treatment choices.

RESULTS

The results of this study will provide new insights into a better understanding of the most relevant factors associated with therapeutic decisions on the use of DMTs, assessing how neurologists handle uncertainty when making treatment choices, and identifying the prevalence of therapeutic inertia in the management of early AD.

The Patient Voice: Exploring Treatment Preferences in Participants with Mild Cognitive Concerns to Inform Regulatory Decision Making

OBJECTIVE

We aimed to assess the feasibility of developing a discrete-choice experiment survey to elicit preferences for a treatment to delay cognitive decline among people with a clinical syndrome consistent with early Alzheimer's disease, including the development of self-reported screening criteria to recruit the sample.

METHODS

Using input from qualitative interviews, we developed a discrete-choice experiment survey containing a multifaceted beneficial treatment attribute related to slowing cognitive decline for respondents with self-reported cognitive concerns. In two rounds of in-person pretest interviews, we tested and revised the survey text and discrete-choice experiment questions, including examples, language, and levels associated with the Alzheimer's Disease Assessment Scale-Cognitive Subscale, along with a set of de novo self-reported questions for identifying respondents who had neither too mild nor too advanced cognitive decline. Self-reported memory and thinking problems were compared with symptoms from studies of patients with early Alzheimer's disease (e.g., mild cognitive impairment, mild Alzheimer's disease) to determine whether those studies' recruited patients were similar to our anticipated target population. Round 1 pretest interviews resulted in significant simplifications in the survey instrument, revisions to the inclusion and exclusion criteria, and revisions to the screening process. In round 2 of the pretest interviews, the ability of participants to provide consistent responses to the self-reported screening questions was further assessed. In addition, to evaluate participants' ability to understand and independently complete the discrete-choice experiment survey, two interviewers independently evaluated each participant's ability to make trade-offs in the discrete-choice experiment questions and to understand the content of the survey.

RESULTS

Round 1 (15 pretest interviews) identified challenges with the survey instrument related to the complexity of the choice questions. The screening process did not screen out seven respondents with more advanced cognitive decline, as determined qualitatively by the interviewers and by these participants' inability to complete the survey. The survey instrument and screening criteria were revised, and an initial online screener was added to the screening process before round 2 pretests. In round 2 pretests, 12 participants reported cognitive problems similar to the target population for the survey but were judged able to understand and independently complete the discrete-choice experiment survey.

CONCLUSIONS

We developed self-reported screening criteria that identified a sample of individuals with memory and thinking concerns who were similar to individuals with clinical symptoms of early Alzheimer's disease and who were able to independently complete a simplified discrete-choice experiment survey. Quantitative patient preference studies provide important information on patients' willingness to trade off treatment benefits/risks. Adapting the technique for patients with cognitive decline requires careful testing and adjustments to survey instruments. This work suggests it is the severity of cognitive impairment, rather than its presence, that determines the ability to complete a simplified discrete-choice experiment survey.

Preventive Drugs for Huntington’s Disease: A Choice-Based Conjoint Survey of Patient Preferences

Introduction:

This research examined the perspective of the Huntington’s disease (HD) community regarding the use of predictive biomarkers as endpoints for regulatory approval of therapeutics to prevent or delay the onset of clinical HD in asymptomatic mutation carriers.

Methods:

An online, choice-based conjoint survey was shared with HD community members including untested at-risk individuals, presymptomatic mutation carriers, and symptomatic individuals. Across 15 scenarios, participants chose among two proposed therapies with differing degrees of biomarker improvement and side effects or a third option of no treatment.

Results:

Two hundred and thirty-eight responses were received. Attributes reflecting biomarker efficacy (e.g., prevention of brain atrophy on magnetic resonance imaging, reduced mutant huntingtin, or reduced inflammation biomarkers) had 3- to 7-fold greater importance than attributes representing side effects (e.g., increased risk of heart disease, cancer, and stroke over 20 years) and were more influential in directing choice of treatments. Reduction in mutant huntingtin protein was the most valued attribute overall. Multinomial logit model simulations based on survey responses demonstrated high interest among respondents (87–99% of the population) for drugs that might prevent or delay HD solely based upon biomarker evidence, even at the risk of serious side effects.

Conclusion:

These results indicate a strong desire among members of the HD community for preventive therapeutics and a willingness to accept significant side effects, even before the drug has been shown to definitively delay disease onset if the drug improves biomarker evidence of HD progression. Preferences of the HD community should inform regulatory policies for approving preventive therapies.

Parent Preferences for Delaying Insulin Dependence in Children at Risk of Stage III Type 1 Diabetes

Background: Autoantibody screening in type 1 diabetes (T1D) may reduce the chances of potentially life-threatening diabetic ketoacidosis (DKA) at diagnosis by allowing individuals at risk of progression to more actively monitor for and/or manage progression to insulin dependence. We investigated parents' preferences for treatments to delay the onset of insulin dependence in children who are at high risk of developing Stage III T1D. Methods: A web-based survey (n = 1501) was administered to a stratified sample of parents (children <18 years) in the United States from an online panel. Parents were told to hypothetically assume that their youngest child would become insulin dependent within 6 months or 2 years and were offered a series of choices between no treatment and two hypothetical treatments that would delay insulin dependence. Random-parameters logit analysis and maximum acceptable risks were used to evaluate the relative importance of treatment benefits and risks. Results: Most parents chose at least one active treatment (2% always chose monitoring only). For parents of children without T1D (n = 901), delaying insulin dependence and reducing the risk of long-term health complications and serious infection were the most important treatment attributes. In addition, parents of children with T1D (n = 600) also valued reducing the risk of hospitalizations due to DKA. Conclusions: When told to assume their child would develop Stage III T1D, most parents considered active treatments to delay progression. For medicines under development to delay insulin dependence in T1D, the preferences expressed in this survey provide guidance on acceptable benefit-risk trade-offs.

Patient preferences for maintenance PARP inhibitor therapy in ovarian cancer treatment

OBJECTIVE

To measure preferences of women with ovarian cancer regarding risks, side effects, costs and benefits afforded by maintenance therapy (MT) with a poly ADP ribose polymerase (PARP) inhibitor.

METHODS

A discrete-choice experiment elicited preferences of women with ovarian cancer regarding 6 attributes (levels in parentheses) relevant to decisions for MT versus treatment break: (1) overall survival (OS; 36, 38, 42 months); (2) progression-free survival (PFS; 15, 17, 21 months); (3) nausea (none, mild, moderate); (4) fatigue (none, mild, moderate); (5) probability of death from myelodysplastic syndrome/acute myelogenous leukemia (MDS/AML; 0% to 10%); (6) monthly out-of-pocket cost ($0 to $1000). Participants chose between 2 variable MT scenarios and a static scenario representing treatment break, with multiple iterations. Random-parameters logit regression was applied to model choices as a function of attribute levels.

RESULTS

95 eligible participants completed the survey; mean age was 62, 48% had recurrence, and 17% were ever-PARP inhibitor users. Participants valued OS (average importance weight 24.5 out of 100) and monthly costs (24.6) most highly, followed by risk of death from MDS/AML (17.9), nausea (14.7), PFS (10.5) and fatigue (7.8). Participants would accept 5% risk of MDS/AML if treatment provided 2.2 months additional OS or 4.8 months PFS. Participants would require gains of 2.6 months PFS to accept mild treatment-related fatigue and 4.4 months to accept mild nausea.

CONCLUSIONS

When considering MT, women with ovarian cancer are most motivated by gains in OS. Women expect at least 3-4 months of PFS benefit to bear mild side effects of treatment.