Estimating an EQ-5D-Y-3L Value Set for Indonesia by Mapping the DCE onto TTO Values

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

Adaptation of the Experimental Version of EQ-5D-Y-5L Into Bahasa Indonesia

OBJECTIVES

The EQ-5D-Y-5L has been developed to provide an appropriate version of EQ-5D for children. This article reports the EQ-5D-Y-5L adaptation process into Bahasa Indonesia.

METHODS

Forward and backward translations were performed to produce equal qualifiers between EQ-5D-Y-5L English and Bahasa versions. Unresolved issues were addressed in a cognitive debriefing, conducted with 10 children aged 8 to 15. A linguist proofread the final stage of the translation.

RESULTS

Differences were found in wordings, headings, font styles, and qualifiers in EQ-5D English versions that require consideration when translating the English version into other languages. Two issues arose: first, levels 1, 2, and 4 in EQ-5D-Y-5L Bahasa matched the levels 1, 2, and 3 of EQ-5D-Y-3L, rather than levels 1, 3, and 4, as is the case in the English versions. Second, the translated words for "pain" and "worried," used in the other EQ-5D Bahasa, were difficult to comprehend. Hence, we replaced these words with alternative Bahasa words at the cost of breaking consistency between the EQ-5D-Y-3L and EQ-5D-Y-5L Bahasa. There was an indication that the extensive cognitive debriefing caused response fatigue in children.

CONCLUSIONS

The adaptation process resulted in a comprehensible EQ-5D-Y-5L Bahasa Indonesia for children aged 8 to 16. Our findings suggest a need to review the existing EQ-5D-Y-3L and EQ-5D-3L in Bahasa Indonesia. While awaiting this review, research related to these 2 measures should be interpreted with caution in the context of international comparisons. Furthermore, we propose consideration of a more user-friendly approach to cognitive debriefing tailored for children.

An Acquired Taste: Latent Class Analysis to Compare Adolescent and Adult Preferences for EQ-5D-Y-3L Health States

OBJECTIVES

US stakeholders advised including adolescents in the valuation study for the EQ-5D-Y-3L, a step toward greater acknowledgment of children in informing societal values. This study aimed to assess the relative contribution of adolescent and adult preferences to a model when combined.

METHODS

Discrete choice experiment data were collected from an online sample of 1529 adults and 714 adolescents (ages 11-17). Each respondent completed 15 discrete choice experiment tasks, which were analyzed using latent class models representing varying number of preference classes. Within the best-fitting model, the contribution of each class was determined by the scale-adjusted class share (SACS), combining the class's proportion of respondents (class share) and the magnitude of coefficients (within-class scale). We estimated the contribution of adolescent and adult respondents to SACS for each class, with lower SACS representing less contribution to the combined model.

RESULTS

The best-fitting model described 6 classes. Adults had higher contribution to all except 1 class, accounting for 78.7% of the total contribution. After adjusting for the unequal sample size of adolescent and adult respondents, adults contributed approximately 65.0%, and adolescents contributed 35.0% of the weights toward a combined model.

CONCLUSIONS

Adolescents showed diminished, disproportionate representation in a combined model, due in part to more indifferent, less informative preferences for EQ-5D-Y-3L health states compared with adults. Latent class analysis showcases one approach to estimate and weight contributions from intentionally sampled subgroups in a combined model.

Assessing the Value for Money of Enzyme Replacement Therapy in Gaucher Disease Types 1 and 3b: Can Expanded Coverage Be Justified?

BACKGROUND AND OBJECTIVES

The Health Intervention and Technology Assessment Program was commissioned to conduct a cost-utility and budget impact analysis of enzyme replacement therapy (ERT) for Gaucher disease types 1 and 3b. The findings from this assessment are to support the decision-making process regarding the potential expansion of ERT coverage within Thailand's public health system.

METHODS

The analysis compared the current policy, which provides treatment with imiglucerase only for patients with Gaucher disease type 1, as listed in the National List of Essential Medicine, with a proposed policy that extends coverage to include Gaucher disease types 1 and 3b with either imiglucerase or velaglucerase. Cost-utility analysis of these policy options was performed using decision tree and Markov models over a lifetime horizon from a societal perspective. The financial implications for the relevant budgetary authority over 5 years were estimated. The research methodology adheres rigorously to Thailand's health technology assessment guidelines.

RESULTS

The study found that the incremental cost-effectiveness ratios for treating both Gaucher disease types 1 and 3b are 6,769,000 and 9,359,000 baht per quality-adjusted life year (QALY) for imiglucerase and velaglucerase, respectively, which is well beyond Thailand's cost-effectiveness threshold of 160,000 baht per QALY. Such an expansion would incur an additional budgetary burden of approximately 81 million baht for imiglucerase and 138 million baht for velaglucerase. Increasing the rate of hematopoietic stem cell transplantation (HSCT) can improve the cost-effectiveness of the expansion.

CONCLUSIONS

The study concludes that expanding ERT with either imiglucerase or velaglucerase to treat both Gaucher disease types 1 and 3b is not cost-effective at current prices in Thailand; however, it could become cost-effective with a reduction of approximately 60% in drug prices or if all eligible patients undergo HSCT.

Measurement Properties of the EQ-5D Instruments in Children and Adolescents: A Systematic Review

BACKGROUND

The EQ-5D instruments have been widely used to measure health-related quality of life (HRQoL) in child and adolescent populations, especially the EQ-5D-Y-3L and EQ-5D-Y-5L (beta version). Although not specifically designed for younger users, the adult versions (EQ-5D-3L and EQ-5D-5L) are also used in these populations. While the measurement properties of these instruments have been evaluated in children and adolescents, no systematic review to date has employed a rigorous method to assess risk of bias. Additionally, quality criteria for good measurement properties and certainty of evidence have not been thoroughly evaluated. The aim of this study was to summarize and critically appraise the evidence on the measurement properties of all EQ-5D instruments in children and adolescents.

METHODS

We conducted electronic searches on MEDLINE, EMBASE, CINAHL, EconLit, National Health Service Economic Evaluation Database (NHS-EED), and Health Technology Assessment (HTA) databases up to May 2024. We included studies measuring HRQoL using either the self-reported or proxy-reported version of the EQ-5D instruments-EQ-5D-3L, EQ-5D-5L, EQ-5D-Y-3L, and EQ-5D-Y-5L-using the descriptive system, visual analogue scale, and/or utility score in children and adolescents up to 19 years of age, and that tested at least one measurement property (e.g., reliability). The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology was followed to assess risk of bias, to score results for measurement properties, and to perform an evidence synthesis using a modified Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach.

RESULTS

From 3586 records identified through the search, 65 studies were included in this systematic review. We found moderate certainty of evidence of sufficient comprehensibility and comprehensiveness of the EQ-5D-Y-3L and EQ-5D-Y-5L. Furthermore, we found very low certainty of evidence of inconsistent relevance for the EQ-5D-Y-3L, whereas the EQ-5D-Y-5L had sufficient relevance. Almost all the measurement properties (reliability, hypothesis testing for construct validity, and responsiveness) considering all the EQ-5D versions ranged from moderate certainty of evidence of insufficient results to very low certainty of evidence of insufficient results.

CONCLUSION

There is moderate certainty of evidence that the EQ-5D-Y-3L and EQ-5D-Y-5L have sufficient content validity. Both instruments can be recommended to measure HRQoL in children and adolescents aged 8-15 years. However, most of the measurement properties across all EQ-5D versions showed insufficient results, with certainty of evidence ranging from moderate to very low due to inconsistency and doubtful to inadequate risk of bias. Therefore, further research is needed to improve the methodological quality of studies on EQ-5D instruments for children and adolescents.

SYSTEMATIC REVIEW REGISTRATION

International prospective register of systematic reviews (PROSPERO): CRD42020218382 and Open Science Framework: https://osf.io/r8kt9/ .

Comparison of EQ-5D-Y-3L Utility Scores Using Nine Country-Specific Value Sets in Chinese Adolescents

OBJECTIVE

This study aimed to assess and compare the measurement properties of EQ-5D-Y-3L utilities derived from available countries' value sets (Chinese, Japanese, Slovenian, German, Spanish, Hungarian, Netherlandish, Belgian, and Indonesian), among Chinese adolescents.

METHODS

From July to September 2021, a large-scale cross-sectional survey was administered across 16 cities in Shandong, China, with the objective of assessing the health status of junior high school students aged 10-18 years. Supported by the educational authorities, quick response (QR) codes and questionnaire links were disseminated to schools. A total of 97,413 junior high school students completed the questionnaire. Agreement, convergent validity, and known-group validity were determined in the nine country-specific value sets.

RESULTS

The Indonesian value set demonstrated the highest mean health utility score (0.970), followed by the Japanese (0.961), Chinese (0.960), Netherlandish (0.948), Hungarian (0.942), German (0.938), Belgian (0.932), Slovenian (0.926), and Spanish (0.926) value sets, respectively. The utility scores derived from Asian value sets were higher than those from Europe. Good or excellent agreements (intraclass correlation coefficients > 0.7) were found between each paired value set. In Bland-Altman plots, the 95% limits of agreement for any two value sets were 0.046-0.348. A strong relationship (Spearman's correlation coefficients > 0.99) between any two value sets was found. The EQ-5D-Y-3L utility scores discriminated equally well for the nine value sets across three known groups. The effect size and the relative efficiency statistics showed the Chinese value sets were more sensitive in general. Referring to the Chinese value set, all the relative efficiency values in each value set were similar across three known groups, ranging from 0.9 to 1.0.

CONCLUSIONS

A total of nine country-specific EQ-5D-Y-3L value sets showed an overall high level of agreement, strong correlation, and good known-group validity. However, the utility scores derived from nine EQ-5D-Y-3L value sets were different and the country-specific value sets were not interchangeable.

EQ‑5D‑Y-3L population norms for children and adolescents in Jiangsu, China

OBJECTIVE

This study aims to establish EQ-5D-Y-3L population norms in Jiangsu, China by conducting a large-scale cross-sectional survey.

METHODS

Children and adolescents aged 9-17 from three cities of Jiangsu Province were selected by multistage stratified random sampling to complete the EQ-5D-Y-3L instrument independently. Population norms for Jiangsu, China were determined by calculating statistics based on age and gender. Logistic and Tobit regression models were employed to explain the relationship between HRQoL and factors such as sociodemographic characteristics/recent acute symptoms (experienced fever/cough/sore throat/diarrhea in the past two weeks).

RESULTS

Three cities yielded 37,574 valid samples (a sample validity rate of 95.4%). The EQ-5D-Y-3L utility values (mean ± SD) were 0.964 ± 0.085 for males and 0.958 ± 0.077 for females. Males scored 85.94 ± 19.62 and females scored 84.83 ± 18.45 on the VAS (mean ± SD), while the percentages of respondents reporting full health ranged from 58.3 to 78.8%. The dimension in which most respondents reported having no problems was "feeling worried, sad, or unhappy" (23.0%). And the lowest HRQoL was shown in the 14-year-old age group. Gender, age, board at school, and BMI were found to have an association with HRQoL. In addition, recent acute symptoms also correlate with some aspects of HRQoL.

CONCLUSIONS

This study established EQ-5D-Y-3L population norms in Jiangsu, China for the first time. These norms will support resource allocation decision-making and be used as a reference for health evaluation studies.

Measuring utility values of eye conditions among children in India using the EQ-5D-Y instrument

BACKGROUND

Vision impairment and blindness are significant global public health challenges, particularly in low- and middle-income countries, where access to eye care services remains limited. India has significantly reduced the prevalence of Blindness and Vision Impairment (VI) over the last two decades. This was achieved with the help of greater investments towards blindness control programs. The use of utility values helps in conducting economic evaluations of various eye health programs and empirically justify investing in these programs. This study aimed to estimate utility values for various childhood eye conditions in central India using the EuroQol-Five-Dimension-Youth (EQ-5D-Y) instrument.

METHODS

This is a before and after study with data collected at two time points for few participants and at only one time point for others. This study was undertaken at Shri Sadguru Netra Chikitsalaya (SNC) and included children representing central and north India. Participants were randomly sampled in the hospital. After comprehensive eye examination, participants completed the EuroQol-Five-Dimension-Youth (EQ-5D-Y) questionnaire along with EuroQol Visual Analogue Scale (EQ VAS) measurement to elicit their health state for their condition which was repeated after six months post-intervention to measure the change in utility value. We have used Indonesian value set to analyze the preference scores of each dimension of EQ-5D-Y.

RESULTS

Utility values of 16 eye conditions were estimated at baseline and seven conditions were followed up for post-intervention utility value estimation. There is a statistically significant improvement in the utility values post-intervention amongst six conditions. Blindness and Pediatric cataract had the greatest change (0.23 and 0.2 respectively) in utility value whereas mild Vision Impairment (VI) showed the least change (0.02) in the utility value post-intervention. Blindness had the lowest baseline (0.62) and post-intervention (0.85) utility value.

CONCLUSION

The utility values estimated in this study showed that generic measures such as EQ-5D-Y may be used to elicit health states for various eye conditions amongst children. These estimates are helpful in undertaking cost-utility analyses of eye health programs and interventions aimed at these eye conditions.

Estimating an EQ-5D-Y-3L Value Set for Brazil

INTRODUCTION

The EQ-5D-Y-3L is a generic measure of health-related quality of life in children and adolescents. Although the Brazilian-Portuguese EQ-5D-Y-3L version is available, there is no value set for it, hampering its use in economic evaluations. This study aimed to elicit a Brazilian EQ-5D-Y-3L value set based on preferences of the general adult population.

METHODS

Two independent samples of adults participated in an online discrete choice experiment (DCE) survey and a composite time trade-off (cTTO) face-to-face interview. The framing was "considering your views for a 10-year-old child". DCE data were analyzed using a mixed-logit model. The 243 DCE predicted values were mapped into the observed 28 cTTO values using linear and non-linear mapping approaches with and without intercept. Mapping approaches' performance was assessed to estimate the most valid method to rescale DCE predicted values using the model fit (R2), Akaike Information Criteria (AIC), root mean squared error (RMSE), and mean absolute error (MAE).

RESULTS

A representative sample of 1376 Brazilian adults participated (DCE, 1152; cTTO, 211). The linear mapping without intercept (R2 = 96%; AIC, - 44; RMSE, 0.0803; MAE, - 0.0479) outperformed the non-linear without intercept (R2 = 98%; AIC, - 63; RMSE, 0.1385; MAE, - 0.1320). Utilities ranged from 1 (full health) to - 0.0059 (the worst health state). Highest weights were assigned to having pain or discomfort (pain/discomfort), followed by walking about (mobility), looking after myself (self-care), doing usual activities (usual activities), and feeling worried, sad, or unhappy (anxiety/depression).

CONCLUSION

This study elicited the Brazilian EQ-5D-Y-3L value set using a mixed-logit DCE model with a power parameter based on a linear mapping without intercept, which can be used to estimate the quality-adjusted life-years for economic evaluations of health technologies targeting the Brazilian youth population.

Who should value children's health and how? An international Delphi study

Valuing child health necessitates normative methodological decisions on whose preferences should be elicited and who should be imagined as experiencing impaired health. Formal guidance is limited and expert consensus unclear. This study sought to establish the degree of consensus among expert stakeholders on normative issues of who to ask and who should be imagined when valuing child health (7-17 years) to inform UK health technology assessment. Sixty-two experts (n = 47 in Round 2) from 18 countries participated in a modified, two-round online Delphi survey (Round 1: May-June 2023; Round 2: September-October 2023). Participants were expert stakeholders in child health valuation, including academics (n = 38); industry/consultancy representatives (including the charity/not-for-profit sector; n = 13); and UK policy/government representatives (n = 11). The Delphi survey was modified between rounds and consisted of 9-point Likert, categorical, multiple-choice, and free-text questions on normative issues in valuing child health. Responses were analysed descriptively and thematically. An a priori criterion of ≥75% agreement was established for formal consensus, while areas approaching consensus (≥70% agreement) and without consensus were identified as a future research primer. Consensus was observed that older adolescents (aged 16-17 years) and adults (18+ years) should be asked to value child health states. There was consensus that the former should think about themselves when valuing the health states and the latter should imagine a child of some form (e.g., imagining themselves as a child or another hypothetical child). However, no consensus was evident on what form this should take. Several other methodological issues also reached consensus. These findings are largely consistent with recent views elicited qualitatively from members of the public and other stakeholders on normative issues in valuing child health. The results mean that, contrary to what has been done in previous child health valuation studies, efforts should be made to involve both older adolescents (16+ years) and adults in child health valuation.

Understanding Canadian stakeholders' views on measuring and valuing health for children and adolescents: a qualitative study

OBJECTIVE

Valuing child health is critical to assessing the value of healthcare interventions for children. However, there remain important methodological and normative issues. This qualitative study aimed to understand the views of Canadian stakeholders on these issues.

METHODS

Stakeholders from health technology assessment (HTA) agencies, pharmaceutical industry representatives, healthcare providers, and academic researchers/scholars were invited to attend an online interview. Semi-structured interviews were designed to focus on: (1) comparing the 3-level and 5-level versions of the EQ-5D-Y; (2) source of preferences for valuation (adults vs. children); (3) perspective of valuation tasks; and (4) methods for valuation (discrete choice experiment [DCE] and its variants versus time trade-off [TTO]). Participants were probed to consider HTA guidelines, cognitive capacity, and potential ethical concerns. All interviews were recorded and transcribed verbatim. Framework analysis with the incidence density method was used to analyze the data.

RESULTS

Fifteen interviews were conducted between May and September 2022. 66.7% (N = 10) of participants had experience with economic evaluations, and 86.7% (N = 13) were parents. Eleven participants preferred the EQ-5D-Y-5L. 12 participants suggested that adolescents should be directly involved in child health valuation from their own perspective. The participants were split on the ethical concerns. Eight participants did not think that there was ethical concern. 11 participants preferred DCE to TTO. Among the DCE variants, 6 participants preferred the DCE with duration to the DCE with death.

CONCLUSIONS

Most Canadian stakeholders supported eliciting the preferences of adolescents directly from their own perspective for child health valuation. DCE was preferred if adolescents are directly involved.

Using Age-Specific Values for Pediatric HRQoL in Cost-Effectiveness Analysis: Is There a Problem to Be Solved? If So, How?

Value sets for the EQ-5D-Y-3L published to date appear to have distinctive characteristics compared with value sets for corresponding adult instruments: in many cases, the value for the worst health state is higher and there are fewer values < 0. The aim of this paper is to consider how and why values for child and adult health differ; and what the implications of that are for the use of EQ-5D-Y-3L values in economic evaluations to inform healthcare resource allocation decisions. We posit four potential explanations for the differences in values: (a) The wording of severity labels may mean the worst problems on the EQ-5D-Y-3L are descriptively less severe than those on the EQ-5D-5L; (b) Adults may genuinely consider that children are less badly affected than adults by descriptively similar health issues. That is, for any given health problem, adult respondents in valuation studies consider children's overall health-related quality of life (HRQoL) on average to be higher than that for adults; (c) Values are being sought by eliciting adults' stated preferences for HRQoL in another person, rather than in themselves (regardless of whether the 'other person' concerned is a child); and (d) The need to elicit preferences for child HRQoL that are anchored at dead = 0 invokes special considerations regarding children's survival. Existing evidence does not rule out the possibility that (c) and (d) exert an upward bias in values. We consider the implications of that for the interpretation and use of values for pediatric HRQoL. Alternative methods for valuing children's HRQoL in a manner that is not 'age specific' are possible and may help to avoid issues of non-comparability. Use of these methods would place the onus on health technology assessment bodies to reflect any special considerations regarding child quality-adjusted life-year gains.

Efficient Designs for Valuation Studies That Use Time Tradeoff (TTO) Tasks to Map Latent Utilities from Discrete Choice Experiments to the Interval Scale: Selection of Health States for TTO Tasks

BACKGROUND

In eliciting utilities to value multiattribute utility instruments, discrete choice experiments (DCEs) administered online are less costly than interviewer-facilitated time tradeoff (TTO) tasks. DCEs capture utilities on a latent scale and are often coupled with a small number of TTO tasks to anchor utilities to the interval scale. Given the costly nature of TTO data, design strategies that maximize value set precision per TTO response are critical.

METHODS

Under simplifying assumptions, we expressed the mean square prediction error (MSE) of the final value set as a function of the number J of TTO-valued health states and the variance VJ of the states' latent utilities. We hypothesized that even when these assumptions do not hold, the MSE 1) decreases as VJ increases while holding J fixed and 2) decreases as J increases while holding VJ fixed. We used simulation to examine whether there was empirical support for our hypotheses a) assuming an underlying linear relationship between TTO and DCE utilities and b) using published results from the Dutch, US, and Indonesian EQ-5D-5L valuation studies.

RESULTS

Simulation set (a) supported the hypotheses, as did simulations parameterized using valuation data from Indonesia, which showed a linear relationship between TTO and DCE utilities. The US and Dutch valuation data showed nonlinear relationships between TTO and DCE utilities and did not support the hypotheses. Specifically, for fixed J, smaller values of VJ reduced rather than increased the MSE.

CONCLUSIONS

Given that, in practice, the underlying relationship between TTO and DCE utilities may be nonlinear, health states for TTO valuation should be placed evenly across the latent utility scale to avoid systematic bias in some regions of the scale.

HIGHLIGHTS

Valuation studies may feature a large number of respondents completing discrete choice tasks online, with a smaller number of respondents completing time tradeoff (TTO) tasks to anchor the discrete choice utilities to an interval scale.We show that having each TTO respondent complete multiple tasks rather than a single task improves value set precision.Keeping the total number of TTO respondents and the number of tasks per respondent fixed, having 20 health states directly valued through TTO leads to better predictive precision than valuing 10 health states directly.If DCE latent utilities and TTO utilities follow a perfect linear relationship, choosing the TTO states to be valued by weighting on the 2 ends of the latent utility scale leads to better predictive precision than choosing states evenly across the latent utility scale.Conversely, if DCE latent utilities and TTO utilities do not follow a linear relationship, choosing the states to be valued using TTO evenly across the latent utility scale leads to better predictive precision than weighted selection does.In the context of valuation of the EQ-5D-Y-3L, we recommend valuing 20 or more health states using TTO and placing them evenly across the latent utility scale.

Analytical Considerations When Anchoring Discrete Choice Experiment Values Using Composite Time Trade-Off Data: The Case of EQ-5D-Y-3L

Discrete choice experiments (DCEs) are becoming increasingly used to elicit preferences for children's health states. However, DCE data need to be anchored to produce value sets, and composite time trade-off (cTTO) data are typically used in the context of EQ-5D-Y-3L valuation. The objective of this paper is to compare different anchoring methods, summarise the characteristics of the value sets they produce, and outline key considerations for analysts. Three anchoring methods were compared using data from published studies: (1) rescaling using the mean value for the worst health state; (2) linear mapping; and (3) hybrid modelling. The worst state rescaling value set had the largest range. The worst state rescaling and linear mapping value sets preserved the relative importance of the dimensions from the DCE, whereas the hybrid model value set did not. Overall, the predicted values from the hybrid model value set were more closely aligned with the cTTO values. These findings are relatively generalisable. Deciding upon which anchoring approach to use is challenging, as there are numerous considerations. Where cTTO data are collected for more than one health state, anchoring on the worst health state will arguably be suboptimal. However, the final choice of approach may require value judgements to be made. Researchers should seek input from relevant stakeholders when commencing valuation studies to help guide decisions and should clearly set out their rationale for their preferred anchoring approach in study outputs.