Exploration of the Reasons Why Health State Valuation Differs for Children Compared With Adults: A Mixed Methods Approach

How do Health State Values Differ When Respondents Consider Adults Versus Children Living in Those States? A Systematic Review

OBJECTIVES

This systematic review examines how different perspectives influence the valuation of child health-related quality of life (HRQoL). Specifically, it explores differences in values when health states are assessed by children, adolescents, or adults (or some combination of these), from the perspective of the first person (self) or the third person (other), and whether specifying (or not) the age of the person living the described health state affects the valuations. Recent studies suggest discrepancies for descriptively similar health states potentially owing to differences in respondents' willingness to trade length-of-life for quality-of-life for children, though findings are inconsistent. This review aims to assess: (1) differences in peoples' willingness to trade, (2) differences between the relative importance of dimensions, and (3) factors influencing these differences.

METHODS

This systematic review follows PRISMA guidelines. A search in Ovid MEDLINE, Ovid Embase, and EconLit up to November 2024 was undertaken. We included studies where different perspectives and different valuation instruments were considered. We extracted information on study characteristics, instruments, valuation methods, perspective, study design, analytical methods, sample characteristics, differences in values by respondents, and perspective. A multi-level meta-regression assessed the impact of factors affecting the mean differences between perspectives.

RESULTS

In total, 24 studies were included, which were from 2004 to 2024. Studies used a range of preference elicitation methods and nearly half (38%) used mixed valuation methods. Most studies (71%) used the EQ- 5D-Y- 3L instrument. Overall, 54% of studies compared adults valuing health states for themselves, or other adult versus adults valuing for other children or themselves as children. The multi-level meta-regression found that the severity of the health state and the valuation method has a significant impact on the mean differences between child and adult values for child health states. In most of the studies when adults are respondents, pain or discomfort was considered as the most important dimension. When adolescent respondents value health states the results are mixed. Qualitative studies identified respondents' difficulty imagining a child in ill health and becoming emotional while thinking about child poor health and early death as potential reasons behind differences in child values versus adult values.

CONCLUSIONS

The evidence suggests that differences in mean values arise when different perspectives are used in valuing severe child health states by adults. These differences are influenced by factors such as health state severity and valuation method. While the review identified the key factors influencing the differences in mean values, an uncertainty remains regarding the optimal choice of preference elicitation and anchoring methods for child health state valuations. Addressing these gaps could refine future valuation methods for child health-related quality-of-life instruments.

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.

Loss aversion in EQ-5D-Y-3L: does it explain differences in willingness to trade-off life years in adults and children?

INTRODUCTION

Earlier work has shown that adults valuing health for 10-year-old children (i.e., in a child perspective) are more reluctant to trade-off life duration than for themselves, generating higher utilities in composite time trade-off (cTTO). The main motivation of this study is to explore if this reluctance can be explained through loss aversion, i.e., losses of life duration weighing more than gains of the same size.

METHODS

100 UK adults completed cTTO tasks for six EQ-5D-Y-3L states and tasks measuring loss aversion. Both sets of tasks were completed from the child perspective and for the respondent themselves, enabling perspective-dependent correction for loss aversion.

RESULTS

A slight majority of participants was explicitly more loss averse for children than for themselves. Health state utilities were higher in the child perspective both before and after correction for loss aversion. Differences between utilities elicited in both perspectives and the variance of cTTO utilities increased considerably after correction.

DISCUSSION

The results suggest that loss aversion does not explain differences in willingness to trade-off life duration between perspectives. Hence, it remains unclear if correction for loss aversion should be recommended when using EQ-5D-Y-3L utilities in practice.

A time trade-off study in the UK, Canada and the US to estimate utilities associated with the treatment of haemophilia

INTRODUCTION

Haemophilia is a rare bleeding disorder caused by a deficient or absent clotting factor, leading to frequent bleeding. Multiple intravenous (IV) infusions have been the standard prophylactic treatment; however, newer treatment options involve less frequent subcutaneous (SC) injections. To inform future health economic evaluations, this study applied the time trade-off (TTO) method for estimation of utilities associated with haemophilia treatment for both people with the disease and potential caregivers.

METHODS

Using the TTO method, utilities were estimated through two online surveys distributed in the UK, Canada and the US. In survey 1 (S1), adults from the general population aged 18 years and above evaluated health states as if they were living with haemophilia themselves and were receiving treatment for the condition. In survey 2 (S2), adults from the general population with a child under the age of 15 years evaluated health states as if they were treating their child for haemophilia. The surveys assessed the following treatment aspects: frequency of treatment, treatment device and injection site reactions.

RESULTS

In total, 812, 739 and 703 respondents completed S1 and 712, 594 and 527 completed S2 in the UK, Canada and the US, respectively. In both surveys, the treatment device was associated with the largest impact on utilities for both people with haemophilia and caregivers. Monthly SC injections with a prefilled pen-device were associated with a significant utility gain compared with SC injections with a syringe and IV infusions. In S1, a lower treatment frequency was preferred in all three countries, while in S2, a lower treatment frequency was preferred only in the UK. Avoiding injection site reactions was associated with a significant utility gain in both surveys, but only in the UK and Canada.

CONCLUSIONS

The study suggests that the administration of haemophilia treatment in particular has an impact on utilities for both people and caregivers living with the disease. Thus, less complex and time-consuming treatment devices are expected to improve health-related quality of life. This can be further modified additively by less frequent administration. These results can inform future health economic analyses of haemophilia and haemophilia treatment.

Comparing heuristic valuation processes between health state valuation from child and adult perspectives

OBJECTIVES

Health state valuation assumes that respondents trade off between all aspects of choice tasks and maximize their utility. Yet, respondents may use heuristic valuation processes, i.e., strategies to simplify or avoid the trade-offs that are core to health state valuation. The objective of this study is to explore if heuristic valuation processes are more prevalent for valuation from a 10-year-old child's perspective compared to the use of an adult perspective.

METHODS

We reused existing data in which EQ-5D health states were valued from adult and child perspectives with composite time trade-off (cTTO) and discrete choice experiment (DCE) tasks. Our analyses focused on comparing completion time and responding patterns across both perspectives. We also explored how reflective of a set of heuristic strategies respondents' choices were in both perspectives.

RESULTS

We found no evidence for systematic differences in completion time across perspectives. Generally, we find different responding patterns in child perspectives, e.g., more speeding, dominance violations, and clustering of utilities at 1.0, 0.8, and 0. Very few heuristic strategies provide a coherent explanation for the observed DCE responses.

CONCLUSION

Our results provide some, albeit indirect, evidence for differences in heuristic valuation processes between perspectives, although not across all data sources. Potential effects of heuristic valuation processes, such as transfer of responsibility, may be identified through studying responding patterns in cTTO and DCE responses.

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.

Testing 2 Alternative Time Trade-Off Methods for Valuation of Children's Health States

OBJECTIVES

Composite time trade-off (cTTO) values for EQ-5D-Y-3L health states tend to be high, raising concerns about sensitivity particularly for mild or moderate health states. We conceptualized and pilot tested 2 alternative time trade-off (TTO) variants: the caregiver TTO (CGTTO) and lag-time TTO (LTTO).

METHODS

We collected CGTTO and LTTO data in China for 10 EQ-5D-Y-3L health states and compared the resulting values, respondent feedback, and task completion times with those from an EQ-5D-Y-3L valuation study using cTTO. We also examined how age and parental status of respondents could affect TTO values.

RESULTS

A total of 304 participants were included in this study. Overall, cTTO showed statistically better results in all feedback questions. On a 5-point Likert scale where lower score means greater agreement, the mean (SD) feedback scores for cTTO, LTTO, and CGTTO were 1.18 (0.58), 1.45 (0.91), and 1.65 (1.02) for "easy to understand"; 1.45 (0.91), 1.94 (1.08), and 1.86 (1.24) for "easy to differentiate"; and 3.61 (1.29), 2.97 (1.33), and 3.02 (1.50) for "difficult to decide," respectively. The mean (SD) TTO values of all 10 states were 0.463 (0.494), 0.387 (0.555), and 0.123 (0.710) for cTTO, LTTO, and CGTTO, respectively. The effects of age and parental status on TTO values differed by the 3 methods.

CONCLUSIONS

LTTO and CGTTO produce values with good characteristics and merit further investigation. Researchers need to be aware of the differences in design and values when using the TTO method to value children's health states.

Can Independently Elicited Adult- and Child-Perspective Health-State Utilities Explain Priority Setting?

OBJECTIVES

Time trade-off (TTO) utilities for EQ-5D-Y-3L health states valued by adults taking a child's perspective are generally higher than their valuations of the same state for themselves. Ceteris paribus, the use of these utilities in economic evaluation implies that children gain less from treatments returning them to full health for a specified amount of time than adults. In this study, we explore if this implication affects individuals' views of priority-setting choices between treatments for adults and children.

METHODS

We elicited TTO utilities for 4 health states in online interviews, in which respondents valued states for a 10-year-old child and another adult their age. Views on priority setting were studied with person trade-off (PTO) tasks involving the same health states. We tested the ability of the subjects' TTO utilities to predict these societal choices in PTO.

RESULTS

There are no significant differences between adult and child health state valuations in our study, but we do observe a substantial preference for treating children over adults in the PTO task.

CONCLUSIONS

Our findings suggest that perspective-dependent health-state utilities only explain a small part of views on priority setting between adults and children. External equity weights might be useful to better explain the higher priority given to children.

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.

Understanding the valuation of paediatric health-related quality of life: a qualitative study protocol

INTRODUCTION

There is evidence from previous studies that adults value paediatric health-related quality of life (HRQoL) and adult HRQoL differently. Less is known about how adolescents value paediatric HRQoL and whether their valuation and decision-making processes differ from those of adults. Discrete choice experiments (DCEs) are widely used to develop value sets for measures of HRQoL, but there is still much to understand about whether and how the methods choices in the implementation of DCE valuation tasks, such as format, presentation and perspective, affect the decision-making process of participants. This paper describes the protocol for a qualitative study that aims to explore the decision-making process of adults and adolescents when completing DCE valuation tasks. The study will also explore the impact of methodological choices in the design of DCE studies (including decisions about format and presentation) on participants' thinking process.

METHODS AND ANALYSIS

An interview protocol has been developed using DCE valuation tasks. Interviews will be conducted online via Zoom with both an adolescent and adult sample. In the interview, the participant will be asked to go through some DCE valuation tasks while 'thinking aloud'. After completion of the survey, participants will then be asked some predetermined questions in relation to various aspects of the DCE tasks. Interviews will be recorded and transcribed and analysed using a thematic analysis approach.

ETHICS AND DISSEMINATION

Ethics approval for this study has been received for the adult sample (UTS ETH20-9632) as well as the youth sample (UTS ETH22-6970) from the University of Technology Sydney Human Research Ethics Committee. Results from this study will inform the methods to be used in development of value sets for use in the health technology assessment of paediatric interventions and treatments. Findings from this study will also be disseminated through national/international conferences and peer-reviewed journals.

Economic Evaluation of Family-Focused Programs When Parents Have a Mental Health Problem: Methodological Considerations

OBJECTIVES

The nature of adverse effects of parental mental health problems and of the interventions to address them may require specific designs of economic evaluation studies. Nevertheless, methodological guidance is lacking. We aim to understand the broad spectrum of adverse effects from parental mental health problems in children and the economic consequences on an individual and societal level to navigate the design of economic evaluations in this field.

METHODS

We conducted a systematic literature search of empirical studies on children's adverse effects from parental mental illness. We clustered types of impact, identified individual and public cost consequences, and illustrated the results in an impact inventory.

RESULTS

We found a wide variety of short- and long-term (mental) health impacts, impacts on social functioning and socioeconomic implications for the children individually, and adverse effects on the societal level. Consequently, public costs can occur in various public sectors (eg, healthcare, education), and individuals may have to pay costs privately.

CONCLUSIONS

Existing evaluations in this field mostly follow standard methodological approaches (eg, cost-utility analysis using quality-adjusted life-years) and apply a short-time horizon. Our findings suggest applying a long-term time horizon (at least up to early adulthood), considering cost-consequence analysis and alternatives to health-related quality of life and quality-adjusted life-years as outcome measures, and capturing the full range of possible public and private costs.

Estimation of Health Utility Scores for Glycogen Storage Disease Type Ia

BACKGROUND

Glycogen Storage Disease Type Ia (GSDIa) is a rare genetic metabolic disorder characterized by hypoglycemia, hepatomegaly, growth failure, and possible seizures/death. Patients frequently consume cornstarch to maintain blood glucose. Evidence demonstrating the impact of GSDIa on health-related quality of life (HRQoL) is lacking. This study aims to understand the burden of GSDIa by obtaining utility values for economic appraisals.

METHODS

A targeted literature review and interviews with experts (n = 4) and caregivers (n = 4) informed the development of health state vignettes describing different GSDIa severities by age and level of hypothetical treatment (i.e., gene therapy) response. Health states reflecting caregivers' experiences were also developed. A convenience sample of the UK general public completed a time trade-off (TTO) exercise. Scores conceptually varied from 0 (dead) to 1 (full health). States were also rated using a visual analog scale (VAS) and the EQ-5D-5L. Data were descriptively summarized.

RESULTS

One hundred participants completed the exercise (male: 48%; mean age: 42 years). Scores were lowest for the adolescent pre-treatment state (TTO = 0.38). Large increments in HRQoL were observed for the response (adult: TTO = 0.86; child: TTO = 0.84) and complete response (adult and child: TTO = 0.94) hypothetical treatment response states. Caregiver values were lowest for the pre-treatment state (TTO = 0.57) and highest for the complete response state (TTO = 0.95). VAS and EQ-5D-5L scores followed a similar pattern.

CONCLUSION

This study found an HRQoL burden on GSDIa patients and caregivers, with potential large improvement from a hypothetical treatment. These findings may be useful for families, clinicians, regulatory agencies, and in therapy economic evaluations.

Time and lexicographic preferences in the valuation of EQ-5D-Y with time trade-off methodology

In the valuation of EQ-5D-Y-3L, adult respondents are asked to complete composite time trade-off (cTTO) tasks for a 10-year-old child. Earlier work has shown that cTTO utilities elicited in such a child perspective are generally higher than when adults take their own perspective. We explore how differences in time preference in child and adult perspectives could explain this effect. Furthermore, as cTTO valuation in a child perspective involves explicit consideration of immediate death for a child, we also consider how cTTO utilities could be affected by decision-makers lexicographically avoiding death in children. We report the results of an experiment in which 219 respondents valued 5 health states in both adult and child perspectives with either a standard cTTO or a lead-time TTO only approach, in which immediate death is less focal. Time preferences were measured in both perspectives. Our results suggest that utilities were lower when lead-time TTO, rather than cTTO, was used. We find large heterogeneity in time preference in both perspectives, with predominantly negative time preference. The influence of time preferences on utilities, however, was small, and correcting for time preferences did not reduce differences between utilities elicited in both perspectives. Surprisingly, we found more evidence for differences in utilities between adult and child perspectives when lead-time TTO was used. Overall, these results suggest that time and lexicographic preferences affect time trade-off valuation in child and adult perspectives, but are not the explanation for differences between these perspectives. We discuss the implications of our findings for EQ-5D-Y-3L valuation.

Value Set for the EQ-5D-Y-3L in Hungary

BACKGROUND

The Hungarian health technology assessment guidelines recommend the use of the EuroQol instrument family in quality-adjusted life-year calculations. However, no national value set exists for the EQ-5D-Y-3L or any other youth-specific instrument.

OBJECTIVE

This study aims to develop a national value set of the EQ-5D-Y-3L for Hungary based on preferences of the general adult population.

METHODS

This study followed the international valuation protocol for the EQ-5D-Y-3L. Two independent samples, representative of the Hungarian general adult population in terms of age and sex were recruited to complete online discrete choice experiment (DCE) tasks and composite time trade-off (cTTO) tasks by computer-assisted personal interviews. Adults valued hypothetical EQ-5D-Y-3L health states considering the health of a 10-year-old child. DCE data were modelled using a mixed logit model with random-correlated coefficients. Latent DCE utility estimates were mapped onto mean observed cTTO utilities using ordinary least squares regression.

RESULTS

Overall, 996 and 200 respondents completed the DCE and cTTO surveys, respectively. For each domain, the value set resulted in larger utility decrements with more severe response levels. The relative importance of domains by level 3 coefficients was as follows: having pain or discomfort > feeling worried, sad or unhappy > mobility > doing usual activities > looking after myself. Overall, 12.3% of all health states had negative utilities in the value set, with the worst health state having the lowest predicted utility of - 0.485.

CONCLUSION

This study developed a national value set of the EQ-5D-Y-3L for Hungary. The value set enables to evaluate the cost utility of health technologies for children and adolescents based on societal preferences in Hungary.

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.

Findings from a Roundtable Discussion with US Stakeholders on Valuation of the EQ-5D-Y-3L

OBJECTIVES

The International Valuation Protocol for the valuation of the EQ-5D-Y-3L provides baseline guidance, but country-specific context is also important. This study aimed to obtain US stakeholders' input on key considerations for youth valuation in the US.

METHODS

A total of 14 stakeholders representing various backgrounds were identified via the investigators' networks. A 2-h online meeting was held to discuss (1) the need for a US value set for the EQ-5D-Y-3L; (2) willingness to pay more for quality-adjusted life-year (QALY) gains for children versus adults; (3) sampling strategies; (4) framing perspectives; and (5) other challenges. The session was recorded, transcribed, and summarized.

RESULTS

Several stakeholders supported paying more for QALY gains for children in recognition of their potential future contributions to society, as well as to avoid potential undervaluation and promote access to innovative treatments. Concerns regarding possible double counting, lack of data to showcase long-term benefits, and dangers of paying more for certain subgroups were also expressed. Most of the stakeholders felt that adolescents could relate to a 10-year-old's perspective better than adults and were capable of self-completing valuation tasks, and thus should be directly included in the valuation study. There were concerns that adults would be inconsistent in their views about a 10-year-old, partly depending on their status as a parent.

CONCLUSIONS

US stakeholders provided insights relevant to youth valuation in a US context and were open to continued dialogue with investigators. This study could be useful to investigators who are conducting youth valuation studies in different countries and seeking stakeholder input.

Valuing EQ-5D-Y: the current state of play

BACKGROUND

For nearly a decade, value sets for the EQ-5D-Y were not available, reflecting challenges in valuing child HRQoL. A methodological research programme led to publication of a valuation protocol in 2020, which was rapidly taken up by local study teams. By the end of 2022, between 11 and 17 EQ-5D-Y value sets will be available, more than for any other child HRQoL measure. It is timely to review the experience of those using the protocol to identify early learnings and remaining issues where more research is needed.

METHODS

In June 2021, the EuroQol Group organised a three-day workshop, bringing together all those involved in EQ-5D-Y value set studies and related methodological research concerning EQ-5D-Y and valuation. Workshop discussions were captured by note taking and recording all sessions and online chat. A narrative summary of all sessions was produced and synthesised to identify points of agreement and aspects of methods where uncertainty remains.

RESULTS

There was broad agreement that DCE is working well as the principal valuation method. However, the most appropriate means of anchoring the latent scale values produced by DCE remains unclear. Some studies have deviated from the protocol by extending the number of states included in TTO tasks, to better support modelling of DCE and TTO. There is ongoing discussion about the relative merits of alternative variants of TTO and other methods for anchoring. Very few studies have consulted with local end-users to gauge the acceptability of methods used to value EQ-5D-Y.

CONCLUSIONS

Priority areas for research include testing alternative methods for anchoring DCE data; exploring the preferences of adolescents; and scale differences in values for EQ-5D-Y and adult EQ-5D states, and implications of such differences for the use of EQ-5D-Y values in HTA. Given the normative elements of the protocol, engaging with HTA bodies and other local users should be the first step for all future value set studies. Value sets undertaken to date are for the three-level EQ-5D-Y. However, the issues discussed in this paper are equally relevant to valuation of the five-level version of EQ-5D-Y; indeed, similar challenges are encountered valuing any measure of child HRQoL.