Reporting Quality of Marginal Rates of Substitution in Discrete Choice Experiments That Elicit Patient Preferences

Patient Preferences for Treatment in Relapsed/Refractory Acute Leukemia in the United Kingdom: A Discrete Choice Experiment

Background

Acute leukemia is a cancer of the white blood cells which progresses rapidly and aggressively. There are two types: acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). The latter has a rare subtype: acute promyelocytic leukemia (APL). For some patients, following first-line treatment, remission is not achieved ("refractory disease"), and for others the leukemia returns after achieving remission ("relapse"). For these individuals, outcomes are typically poor. It is, therefore, important to understand patients' treatment priorities in this context.

Methods

Building upon formative qualitative research, an online survey containing a discrete choice experiment (DCE) was designed to explore patients' treatment preferences in the relapsed/refractory setting. The DCE attributes were mode of administration; quality of life during treatment; chance of response; duration of response; and quality of life during response. Each respondent completed twelve scenarios containing two hypothetical treatments. Participants were eligible if they lived in the United Kingdom and had a diagnosis of acute leukemia. The data were analysed using a latent class model.

Results

A total of 95 patients completed the survey. The latent class analysis identified two classes. For both, chance of response was the most important attribute. For class 1, every attribute was important, whereas for class 2, the only important attributes were quality of life (during treatment and response) and chance of response. A greater proportion of respondents would fall into class 1 overall, and those with ALL or APL and those more recently diagnosed were more likely to be in class 2.

Conclusion

Our results indicate that patients are strongly concerned about the chance of response, as well as quality of life (to a lesser extent), when faced with different treatment options in the relapsed/refractory setting. However, there is significant preference heterogeneity within the patient population, and other treatment characteristics also matter to many.

Patient preferences for physical therapy programs after a lower extremity fracture: a discrete choice experiment

OBJECTIVE

To quantify patients' preferences for physical therapy programmes after a lower extremity fracture and determine patient factors associated with preference variation.

DESIGN

Discrete choice experiment.

SETTING

Level I trauma centre.

PARTICIPANTS

One hundred fifty-one adult (≥18 years old) patients with lower extremity fractures treated operatively.

INTERVENTION

Patients were given hypothetical scenarios and asked to select their preferred therapy course when comparing cost, mobility, long-term pain, session duration, and treatment setting.

MAIN OUTCOME MEASURES

A multinomial logit model was used to determine the relative importance and willingness to pay for each attribute.

RESULTS

Mobility was of greatest relative importance (45%, 95% CI: 40% to 49%), more than cost (23%, 95% CI: 19% to 27%), long-term pain (19%, 95% CI: 16% to 23%), therapy session duration (12%, 95% CI: 9% to 5%) or setting (1%, 95% CI: 0.2% to 2%). Patients were willing to pay US$142 more per session to return to their preinjury mobility level (95% CI: US$103 to US$182). Willingness to pay for improved mobility was higher for women, patients aged 70 years and older, those with bachelor's degrees or higher and those living in less-deprived areas. Patients were willing to pay US$72 (95% CI: US$50 to US$93) more per session to reduce pain from severe to mild. Patients were indifferent between formal and independent home therapy (willingness to pay: -US$12, 95% CI: -US$33 to US$9).

CONCLUSIONS

Patients with lower extremity fractures highly value recovering mobility and are willing to pay more for postoperative physical therapy programmes that facilitate returning to their pre-injury mobility level. These patient preferences might be useful when prescribing and designing new techniques for postoperative therapy.

Preferences for Adjuvant Immunotherapy in Adults with Resected Stage III Melanoma-A Discrete Choice Experiment

OBJECTIVES

This study aimed to quantify adult preferences for adjuvant immunotherapy for resected melanoma and the influence of varying levels of key attributes and baseline characteristics.

METHODS

A D-efficient design generated 12 choice tasks for two alternative treatments, adjuvant immunotherapy or no adjuvant immunotherapy. Recruitment to the online discrete choice experiment (DCE) occurred via survey dissemination by eight Australian melanoma consumer and professional groups, targeting adults with resected stage III melanoma, considering or having received adjuvant immunotherapy. The DCE included six attributes with two to three levels each, including 3-year risk of recurrence, mild, permanent and fatal adverse events (AEs), drug regimen and annual out-of-pocket costs. A mixed multinomial logit model was used to estimate preferences and calculate marginal rates of substitution and marginal willingness to pay (mWTP).

RESULTS

The DCE was completed by 116 respondents, who chose adjuvant immunotherapy over no adjuvant immunotherapy in 70% of choice tasks. Respondents preferred adjuvant immunotherapy when associated with reduced: probabilities of recurrence, permanent and fatal AEs, and out-of-pocket costs. mWTP for an absolute reduction of 1% in 3-year risk of recurrence was less for respondents with lower rather than higher incomes, AU$794 (US$527) and AU$2190 (US$1454) per year. Respondents accepted an additional 4% chance of a permanent AE to reduce their absolute risk of 3-year recurrence by 1%. Respondents were willing to accept an extra 2% chance of 3-year recurrence to lower their chance of a fatal AE by 1%.

CONCLUSIONS

Almost three-quarters of respondents chose adjuvant immunotherapy over no adjuvant immunotherapy, preferring treatment that improved efficacy and safety. Findings may inform decisions about access to adjuvant immunotherapy following surgery for melanoma.

A Discrete Choice Experiment to Assess Patient Preferences for Asthma Rescue Therapy and Disease Management

BACKGROUND

With the expanding treatment landscape for asthma, the process of identifying best-fit, individualized management options is becoming increasingly complicated. Understanding patients' preferences can inform shared decision-making between clinicians and patients.

OBJECTIVES

To examine preferences of adults with asthma for therapeutic and management attributes and determine how these preferences vary among patients.

METHODS

We conducted an online discrete choice experiment survey in US adults with asthma. Patient preferences were analyzed using logit models. Factors affecting patients' preferences were identified by least absolute shrinkage and selection operator analysis.

RESULTS

A total of 1,184 patients completed the survey (60% female; mean [SD] age, 49.2 [15.0] years). Patients most valued fewer asthma attacks requiring urgent health care professional visits, fewer exacerbations requiring oral corticosteroids, and a reduced risk for oral thrush. Higher value was placed on reducing the risk of short-term (oral thrush) versus long-term side effects (diabetes). Patients were willing to increase rescue medication use in exchange for decreasing exacerbations requiring oral corticosteroids and attacks requiring urgent health care professional visits. Patients preferred a single inhaler for rescue and maintenance and least valued asthma action plans. Demographic, socioeconomic, and clinical factors affected patient preferences.

CONCLUSIONS

Patients sought convenient management options that focused mainly on decreasing the short-term morbidity associated with asthma exacerbations and therapies. Preferences varied by demographics, clinical factors, and socioeconomics. It is important for shared decision-making discussions to include conversations about morbidity and how available therapeutic options align with individual patient preferences.

Quantifying Benefit-Risk Trade-Offs Toward Prophylactic Treatment Among Adult Patients With Hemophilia A in China: Discrete Choice Experiment Study

BACKGROUND

Hemophilia A is a chronic condition that requires meticulous treatment and management. Patient preferences for prophylactic treatment can substantially influence adherence, outcomes, and quality of life, yet these preferences remain underexplored, particularly in China.

OBJECTIVE

This study aimed to investigate the preferences for prophylactic treatment among Chinese adult patients with hemophilia A without inhibitors, considering clinical effectiveness, side effects, dosing mode, and dosing frequency.

METHODS

A discrete choice experiment was used to elicit patient preferences for prophylactic treatment of hemophilia. The study was conducted across 7 provinces in China with socioeconomic and geographical diversity. Subgroup analysis was performed according to education level, geographic location, and treatment type, alongside the exploration of benefit-risk trade-offs.

RESULTS

A total of 113 patients completed the discrete choice experiment questionnaire, and we included 102 responses for analysis based on predetermined exclusion criteria. The study found that patients prioritized reducing annual bleeding times and avoiding the risk of developing inhibitors over treatment process attributes. Subgroup analysis revealed that lower-educated patients and those from rural areas attached more importance to the dosing mode, likely due to barriers to self-administration. Patients demonstrated a clear understanding of benefit-risk trade-offs, exhibiting a willingness to accept an increased risk of developing inhibitors for improved clinical outcomes.

CONCLUSIONS

This study provides valuable insights into the preferences of patients with hemophilia A for prophylactic treatment in China. Understanding these preferences can enhance shared decision-making between patients and clinicians, fostering personalized prophylactic treatment plans that may optimize adherence and improve clinical outcomes.

Do preferences differ based on respondent experience of a health issue and its treatment? A case study using a public health intervention

OBJECTIVES

Preference information is increasingly being elicited to support decision-making. Although discrete choice experiments (DCEs) are commonly used, little is known about how respondents' relative experience of a health issue, and its treatment, might impact the results of preference studies. The aim of this study was to explore how preferences differ between groups of individuals with varying levels of experience of a health issue and its treatment, using a weight loss maintenance (WLM) programme as a case study.

METHODS

An online DCE survey was provided to four groups, each differing in their level of experience with weight loss and WLM programmes. One group was recruited from a randomised controlled trial of a WLM programme (ISRCTN14657176) and the other three from an online panel. Choice data were analysed using mixed logit models. Relative attribute importance scores and willingness-to-pay (WTP) estimates were estimated to enable comparisons between groups.

RESULTS

Preferences differed between the groups across different attributes. The largest differences related to the outcome (weight re-gain) and cost attributes, resulting in WTP estimates that were statistically significantly different. The most experienced group was willing to pay £0.35 (95% CI: £0.28, £0.42) to avoid a percentage point increase in weight re-gain, compared with £0.12 (95% CI: £0.08, £0.16) for the least experienced group.

CONCLUSION

This study provides evidence in a public health setting to suggest that preferences differ based on respondent experience of the health issue and its treatment. Health preference researchers should therefore carefully consider the appropriate composition of their study samples.

Preferences of Patients With Chronic Kidney Disease for Invasive Versus Conservative Treatment of Acute Coronary Syndrome: A Discrete Choice Experiment

Background Patients with chronic kidney disease (CKD) can experience acute coronary syndromes (ACS) with high morbidity and mortality. Early invasive management of ACS is recommended for most high-risk patients; however, choosing between an early invasive versus conservative management approach may be influenced by the unique risk of kidney failure for patients with CKD. Methods and Results This discrete choice experiment measured the preferences of patients with CKD for future cardiovascular events versus acute kidney injury and kidney failure following invasive heart procedures for ACS. The discrete choice experiment, consisting of 8 choice tasks, was administered to adult patients attending 2 CKD clinics in Calgary, Alberta. The part-worth utilities of each attribute were determined using multinomial logit models, and preference heterogeneity was explored using latent class analysis. A total of 140 patients completed the discrete choice experiment. The mean age of patients was 64 years, 52% were male, and mean estimated glomerular filtration rate was 37 mL/min per 1.73 m². Across the range of levels, risk of mortality was the most important attribute, followed by risk of end-stage kidney disease and risk of recurrent myocardial infarction. Latent class analysis identified 2 distinct preference groups. The largest group included 115 (83%) patients, who placed the greatest value on treatment benefits and expressed the strongest preference for reducing mortality. A second group of 25 (17%) patients was identified who were procedure averse and had a strong preference toward conservative management of ACS and avoiding acute kidney injury requiring dialysis. Conclusions The preferences of most patients with CKD for management of ACS were most influenced by lowering mortality. However, a distinct subgroup of patients was strongly averse to invasive management. This highlights the importance of clarifying patient preferences to ensure treatment decisions are aligned with patient values.

Does the evaluability bias hold when giving to animal charities?

When evaluating a charity by itself, people tend to overweight overhead costs in relation to cost-effectiveness. However, when evaluating charities side by side, they base their donations on cost-effectiveness. I conducted a replication and extension of Caviola et al. (2014; Study 1) using a 3 (High Overhead/Effectiveness, Low Overhead/Effectiveness, Both) x 2 (Humans, Animals) between-subjects design. I found that the overhead ratio is an easier attribute to evaluate than cost-effectiveness in separate evaluation, and, in joint evaluation, people allocate donations based on cost-effectiveness. This effect was observed for human charities, and to a lesser extent, for animal charities.

Organic food labels bias food healthiness perceptions: Estimating healthiness equivalence using a Discrete Choice Experiment

Individuals perceive organic food as being healthier and containing fewer calories than conventional foods. We provide an alternative way to investigate this organic halo effect using a mirrored method to Choice Experiments applied to healthiness judgments. In an experimental study (N = 415), we examined whether healthiness judgments toward a 200g cookie box are impacted by the organic label, nutrition information (fat and sugar levels), and price and determined the relative importance of these attributes. In particular, we assessed whether food with an organic label could contain more fat or sugar and yet be judged to be of equivalent healthiness to food without this label. We hoped to estimate the magnitude of any such effect. Moreover, we explored whether these effects were obtained when including a widely used system for labeling food healthiness, the Traffic Light System. Although participants' healthiness choices were mainly driven by the reported fat and sugar content, the organic label also influenced healthiness judgments. Participants showed an organic halo effect leading them to consider the organic cookie as healthy as a conventional one despite containing more fat and sugar. Specifically, they considered the organic cookie as equivalent in healthiness to a conventional one, although containing 14% more of the daily reference intake for sugar and 30% more for fat. These effects did not change when including the Traffic Light System. This effect of the organic label could have implications for fat and sugar intake and consequent impacts on health outcomes.

Patient and retina specialists' preferences in neovascular age-related macular degeneration treatment. A discrete choice experiment

INTRODUCTION AND OBJECTIVE

Neovascular age-related macular degeneration (nAMD) leads to severe and permanent visual impairment, significantly impacting patients' quality of life and functional independence. Although treatment with anti- vascular endothelial growth factor (VEGF) prevents and, in some cases, reverses visual damage, the need for frequent monitoring visits and intravitreal injections represents a significant burden on patients, caregivers and retina specialists.

OBJECTIVE

To elicit preferences for nAMD treatment characteristics from the perspectives of patients and retina specialists.

METHOD

A discrete choice experiment was conducted. Participants (patients > 50 years with nAMD receiving anti-VEGF drugs for at least 2 years and without previous experience with anti-VEGF and retina specialists working in the Spanish National Healthcare System) were asked to select one of two hypothetical treatments resulting from the combination of five attributes (effects on visual function, effects on retinal fluid, treatment regimen, monitoring frequency, and cost); their levels were identified by reviewing the literature and two focus groups. The relative importance (RI) given to each attribute was estimated using a mixed logit model. The marginal rates of substitution (MRS) were calculated taking cost as the risk attribute.

RESULTS

A total of 110 patients (P) [aged 79.0 (SD:7.4) years; 57.3% women; 2.3 (SD:0.7) years with nAMD; 2.1 years (SD:0.1) in treatment] and 66 retina specialists (RS) participated in the study. Participants gave greater RI to improvements in their visual function [60.0% (P); 52.7% (RS)], lower monitoring frequency [20.2% (P); 27.1% (RS)] and reduction in retinal fluid [9.8% (P); 13.0%(RS)]. Patients and retina specialists would agree to an increase in cost by 65.0% and 56.5%, respectively, in exchange for improvements of visual function; and 25.5% and 43.3% on delaying monitoring frequency by one month.

CONCLUSIONS

Efficacy of treatment, in terms of visual function improvements, is the main driver for treatment election for both patients and retina specialists. Treatment monitoring requirements are also considered, mainly from the retina specialist's perspective. These results suggest that the use of more efficacious anti-VEGF agents with a longer duration of action may contribute to aligning treatment characteristics with patients/specialists' preferences. A better alignment would facilitate better disease management, fulfilling the unmet needs of patients and retina specialists.

Preferences based interventions to address the use of antibiotics without prescription: A discrete choice experiment

Background

In many countries, concerns have arisen over the population using antibiotics without consulting a physician. This practice can place patients at risk and increase antibiotic resistance in the community.

Objective

To evaluate individuals' preferences regarding the use of antibiotics. The study also assessed the likely effectiveness of interventions aimed at reducing inappropriate use of antibiotics.

Methods

A discrete choice experiment (DCE) was conducted in Bogotá, Colombia. The attributes were determined by a systematic literature review and four focus group sessions. The DCE included nine factors - cost, time to get attention, level of symptoms, efficacy, safety, among others- and one label -using or not antibiotics. Data analysis was carried out using a generalized multinomial logit (GMNL) model. Marginal probabilities of different sets of attributes' levels were compared to estimate the likely effectiveness of interventions.

Results

The survey was administered to 222 participants from diverse socioeconomic backgrounds. The results suggest that participants preferred not taking antibiotics and having a physician as an advisor, but the probability of inappropriate antibiotic use increased as the waiting time or the cost of receiving advice rose. The pharmacy was the preferred source of antibiotics, and participants chose the pharmacy worker (nonprofessional) as an advisor over the nurse on the phone. In the absence of any interventions aimed at reducing the use of antibiotics, approximately 47.3% of people would misuse antibiotics. This reduces to 26.5% when people perceive the efficacy of the antibiotics as low and the potential risks of self-medicating as high. An alternative model using a nursing service would likely lower inappropriate use of antibiotics.

Conclusions

Even though people prefer not using antibiotics or visiting a physician in case of disease rather than self-medicating, current access conditions might discourage them from appropriately use antibiotics. The results suggest that interventions that informing people about the risks of self-medication and the low efficacy might significantly reduce inappropriate use of antibiotics. Our results also suggest that programs that empower other health professionals to provide access to antibiotics would likely further lower inappropriate use.

Utility Values Associated with Atypical Hemolytic Uremic Syndrome-Related Attributes: A Discrete Choice Experiment in Five Countries

BACKGROUND

Atypical hemolytic uremic syndrome is a rare disease caused by complement dysregulation that can lead to progressive kidney damage or death if untreated. Owing to its rarity, the impact of atypical hemolytic uremic syndrome and available therapies (eculizumab and ravulizumab) on patients' health-related quality of life is difficult to describe, but such data are required for an economic evaluation.

OBJECTIVE

The objective of this study was to estimate utility values for atypical hemolytic uremic syndrome-related attributes in five countries for an economic evaluation.

METHODS

Using discrete choice experiment surveys, key atypical hemolytic uremic syndrome-related attributes (life expectancy, administration frequency, risk of meningitis, need for hospitalization, and risk of kidney impairment) were evaluated in adult general population samples from Australia, Canada, the Netherlands, Sweden, and the UK. Survey choice sets were constructed using a published orthogonal array. A mixed-effects logit model estimated preference strength for each attribute. Utilities were estimated using marginal substitution rates between overall survival and other attributes, weighted against average life expectancy.

RESULTS

Across all countries (N = 2382), utility weights revealed a consistent pattern: participants were averse to the risk of kidney impairment (disutility/utility weight range: -0.185 to -0.158), risk of meningitis (-0.041 to -0.032), and the need for hospitalization (-0.063 to -0.048), but preferred 8-weekly vs 2-weekly infusions over 1 h (0.013-0.039).

CONCLUSIONS

Although all attributes played a role in determining treatment preferences, the largest drivers were life expectancy and risk of kidney impairment. Participants favored 8-weekly dosing (corresponding to ravulizumab administration frequency) vs 2-weekly dosing. The discrete choice experiment was designed such that estimated (dis)utility weights can be used in future cost-effectiveness models in atypical hemolytic uremic syndrome.

A Systematic and Critical Review of Discrete Choice Experiments in Asthma and Chronic Obstructive Pulmonary Disease

Background

Regulators have called for greater emphasis on the role of the patient voice to inform medical product development and decision making, and expert guidelines and reports for asthma and chronic obstructive pulmonary disease (COPD) both explicitly recommend the consideration of patient preferences in the management of these diseases. Discrete choice experiments (DCEs) are commonly used to quantify stakeholders’ treatment preferences and estimate the trade-offs they are willing to make between outcomes such as treatment benefits and risks.

Objective

The aim of this systematic literature review is to provide an up-to-date and critical review of DCEs published in asthma and COPD; specifically, we aim to evaluate the subject of preference studies conducted in asthma and COPD, what attributes have been included, stakeholders’ preferences, and the consistency in reporting of instrument development, testing and reporting of results.

Methods

A systematic review of published DCEs on asthma and COPD treatments was conducted using Embase, Medline and the Cochrane Database of Systematic Reviews. Studies were included if they included a DCE conducted in a relevant population (e.g. patients with asthma or COPD or their caregivers, asthma or COPD-treating clinicians, or the general population), and reported quantitative outcomes on participants’ preferences. Study characteristics were summarised descriptively, and descriptive analyses of attribute categories, consistency in reporting on key criteria, and stakeholder preferences were undertaken.

Results

A total of 33 eligible studies were identified, including 28 unique DCEs. The majority (n = 20; 71%) of studies were conducted in a patient sample. Studies focused on inhaler treatments, and included attributes in five key categories: symptoms and treatment benefits (n = 23; 82%), treatment convenience (n = 19; 68%), treatment cost (n = 17; 61%), treatment risks (n = 13; 46%), and other (n = 10; 36%). Symptoms and treatment benefits were the attributes most frequently ranked as important to patients (n = 26, 72%), followed by treatment risks (n = 7, 39%). Several studies (n = 9, 32%) did not qualitatively pre-test their DCE, and a majority did not report the uncertainty in estimated outcomes (n = 18; 64%).

Conclusions

DCEs in asthma and COPD have focused on treatment benefits and convenience, with less evidence generated on participants’ risk tolerance. Quality criteria and reporting standards are needed to promote study quality and ensure consistency in reporting between studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-021-00536-w.