'Like holding the axe on who should live or not': adolescents' and adults' perceptions of valuing children's health states using a standardised valuation protocol for the EQ-5D-Y-3L

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.

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.

How Do Individuals Value Worse-Than-Dead EQ-5D-5L Health States in Composite Time Trade-Off Tasks? A Qualitative Study

OBJECTIVES

Limited knowledge exists regarding individuals' thought processes when valuing health states using composite time trade-off (cTTO) tasks, particularly for health states considered worse than dead (WTD). This study aimed to explore the reasons for WTD perception, the strategies respondents used to value WTD states, and the challenges they faced during cTTO tasks.

METHODS

This qualitative investigation was embedded within a methodological EQ-5D-5L valuation study involving the general public in Singapore, where respondents completed 7 cTTO and 7 novel TTO tasks. Semistructured interviews were conducted with respondents who assigned WTD values to 1 or more health states in the cTTO tasks. Interviews were recorded, transcribed verbatim, and analyzed using framework analysis.

RESULTS

Nineteen respondents were interviewed (age range: 21-71 years old). Respondents identified a range of interconnected factors leading to WTD valuation, including health state and its duration, personal beliefs and circumstances, and consequences of poor health. Although respondents usually considered these factors thoroughly and were capable of complex trading-off between life years and health, some respondents resorted to heuristic strategies to simplify the valuation process, including attribute nonattendance, affect heuristic, and elimination-by-aspects strategies. Respondents encountered various difficulties when they completed the cTTO tasks, including identifying the indifference point, transitioning from conventional TTO to lead-time TTO, and interpreting and imagining health states.

CONCLUSIONS

This study investigated how individuals value WTD health states in cTTO tasks. It suggested that cTTO needs improvement and provided insights into how to improve the design of valuation tasks for severe health states.

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.

Testing "Pits" Time Trade-Off: Can Data Quality be Improved by Removing Death From Valuation of Health States?

OBJECTIVES

Composite time trade-off (cTTO) often exhibits issues such as a value clustering at -1, potentially due to suboptimal valuation task design. We developed a novel time trade-off which uses the "pits" state as an anchor state and enables a unified time trade-off procedure for all health states (referred to as "pTTO"). This study aimed to test the pTTO for valuation of EQ-5D-5L health states.

METHODS

A total of 120 members of the general public were invited to value 3 pairs of dominant/dominated EQ-5D-5L states using both cTTO and pTTO and the "pits" state using cTTO. We compared the pTTO with cTTO in terms of feasibility (interviewer-rated task-completing difficulty), acceptability (participant-reported task experience), value distribution, logical consistency, and discriminatory ability (using the standardized response mean, an effect size measure, derived from 3 pairwise comparisons of states with dominant/dominated relationship).

RESULTS

The pTTO demonstrated similar feasibility to cTTO but slightly lower acceptability. The pTTO values exhibited a smoother and more continuous distribution compared with cTTO values. Relative to the cTTO, the pTTO showed higher individual-level logical consistency rate for the pairs comprising severe states (stringent criterion: 53.04% vs 17.39%; less stringent criterion: 82.61% vs 78.26%). The standardized response mean value based on pTTO values were higher than those based on cTTO values for the pair comprising severe states (0.388 vs -0.140).

CONCLUSIONS

The pTTO appeared to be feasible and acceptable to value EQ-5D-5L states. The pTTO values were less clustered, more logically consistent, and discriminative compared with the cTTO values for severe health states.

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 UK public views on normative decisions made to value health-related quality of life in children: A qualitative study

Developing methodology for measuring and valuing child health-related quality of life (HRQoL) is a priority for health technology agencies. One aspect of this is normative decisions that are made in child HRQoL valuation. This qualitative study aimed to better understand adult public opinion on the normative questions of whose preferences to elicit (adults, children, or both) and from which perspective (who should be imagined living in impaired health), when valuing child HRQoL. Opinions of the adult UK public (N = 32) were solicited using online semi-structured focus groups, featuring a breadth of age, sex, ethnicities, and responsibility for children under 18 years. Participants were provided with bespoke informational material on health state valuation and were probed for their views. Arguments for and against different positions were discussed. Data was analysed using framework analysis. Participants demonstrated near-to-universal agreement that children should be involved in valuation in some form, yet this should differ depending on age or maturity. There was strong support for approaches combining involvement from children and adults (e.g., their parents), especially for younger children. There was little intuitive support for the 'taxpayer argument' for asking taxpaying adults. In the context of greater involvement of children in valuation, most participants supported using an 'own' perspective. Most participants thought that valuation study participants should know the exercise is about valuing child health states for ethical reasons. Informed views from the UK public on who should be asked and with what perspective when valuing child HRQoL appear to differ from normative positions previously advocated by some health economists, such as prioritising the preferences of taxpaying adults. In contrast, the results suggest including adults and children in valuation, with the proviso that the children are of an appropriate age and level of maturity, and that an own perspective is used wherever possible.

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.

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.

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

INTRODUCTION

The standard EQ-5D-Y-3L valuation protocol applies DCE data as the primary preference source to model the relative importance of dimensions while cTTO data served to anchor the DCE coefficients onto the QALY scale. This study aims to estimate an EQ-5D-Y-3L value set for China following this protocol, but with a larger cTTO design to better understand the role of cTTO data in estimating EQ-5D-Y-3L value sets.

METHODS

In total, 150 choice sets and 28 EQ-5D-Y-3L health states were valued using DCE and cTTO methods with two independent samples, respectively. General public from 14 different regions were recruited using quota sampling method to achieve representativeness. We compared two modelling strategies: (1) fit the DCE data with mixed logit model with correlated coefficients and a subsequent mapping procedure for anchoring; (2) fit the DCE and TTO data jointly in a hybrid model. Two evaluation criteria (1) coefficient significance and monotonicity; (2) prediction accuracy of the observed cTTO values were used to select the value set.

RESULTS

In total, 1476 individuals participated in the study, with 1058 participated the DCE interview and 418 participated the cTTO interview. The highest mean TTO value was 0.924 for state 11112 and the lowest mean TTO value was - 0.088 for state 33333. The hybrid model with an A3 term performed the best and was selected as the value set.

DISCUSSION

Following the international protocol and using a larger cTTO design, this study established the EQ-5D-Y-3L value set using a hybrid model for China. Future EQ-5D-Y-3L valuation study could consider using a larger cTTO design for estimating the value set.