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.

This Dead or That Dead: Framing Effects in the Evaluation of Health States.

OBJECTIVES: Current approaches to health state valuation rely on credible classification of states as either "better than dead" or "worse than dead" (WTD). We investigate how such evaluations of health states are affected by the framing in pairwise comparison tasks. METHODS: We conducted an online survey with 361 participants to compare the propensity to evaluate a state as WTD under 6 frames: (A) using a regular time trade-off (TTO) choice task, (B) using a lead-time TTO choice task, (C) excluding the immediacy of death, (D) avoiding reference to the process of dying, (E) focusing on longevity, and (F) focusing on improvements in quality of life. Each participant evaluated 9 EQ-5D-5L health states using 3 frames. The frames were compared using several statistical approaches to confirm robustness to indirect comparisons or respondent heterogeneity and inattentiveness. RESULTS: The odds of a state being evaluated as WTD, compared with frame A, increase 2.7-fold and 1.5-fold in frame B and E, respectively, and decrease >5-fold in frame F. Frames C and D do not differ significantly from frame A. CONCLUSIONS: Different framings for questions about whether a state is WTD or better than dead, even if theoretically equivalent, yield substantially different results. Notably, whether a state is evaluated as WTD differs greatly between the regular TTO and lead-time TTO choice tasks and when either final outcomes or improvements over time are considered.

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.

The effect of duration and time preference on the gap between adult and child health state valuations in time trade-off.

Composite time trade-off (cTTO) utilities have been found to be higher when adults value health states for children than for themselves. It is not clear if these differences reflect adults assigning truly higher utilities to the same health state in different perspectives, or if they are caused by other factors, which are not accounted for in the valuation procedure. We test if the difference between children's and adults' cTTO valuations changes if a longer duration than the standard 10 years is used. Personal interviews with a representative sample of 151 adults in the UK were conducted. We employed the cTTO method to estimate utilities of four different health states, where adults considered states both from their own and a 10-year-old child's perspective, for durations of 10 and 20 years. We corrected the cTTO valuations for perspective-specific time preferences in a separate task, again for both perspectives. We replicate the finding that cTTO utilities are higher for the child perspective than for the adult perspective, although the difference is only significant when controlling for other variables in a mixed effects regression. Time preferences are close to 0 on average, and smaller for children than adults. After correcting TTO utilities for time preferences, the effect of perspective is no longer significant. No differences were found for cTTO tasks completed with a 10- or 20-year duration. Our results suggest that the child-adult gap is partially related to differences in time preferences and, hence, that correcting cTTO utilities for these preferences could be useful.

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.

Modifying the Composite Time Trade-Off Method to Improve Its Discriminatory Power.

OBJECTIVES: In cost-effectiveness analysis of health technologies, health state utilities are needed. They are often elicited with a composite time trade-off (cTTO) method, particularly for the widely used EQ-5D-5L. Unfortunately, cTTO discriminatory power is hindered by (1) respondents' nontrading (NT) of time for quality, (2) censoring of utilities at -1, and (3) poor correlation of negative utilities with state severity. We investigated whether modifying cTTO can mitigate these effects. METHODS: We interviewed online 478 students (February to April, 2021) who each valued the same 10 EQ-5D-5L health states in 1 of 3 arms. Arm A used a standard cTTO, expanded with 2 questions to explore reasons for NT and censoring. Arms B and C used a time trade-off with modified alternatives offered to overcome loss aversion, to unify the tasks for positive and negative utilities, and to enable eliciting utilities < -1. RESULTS: In arms B and C, we observed less NT than in A (respectively, 4% and 4% vs 10%), more strictly negative utilities (38% and 40% vs 25%), and more utilities ≤ -1 (18% and 30% vs 10%). The average utility of state 55555 dropped to -2.15 and -2.52 from -0.53. Enabling finer trades in arm A reduced NT by 70%. Arms B and C yielded an intuitive association between negative utilities and state severity. These arms were considered more difficult and resulted in more inconsistencies. CONCLUSIONS: The discriminatory power of cTTO can be improved, but it may require increasing the difficulty of the task. The standard cTTO may overestimate the utilities, especially of severe states.

In a Child's Shoes: Composite Time Trade-Off Valuations for EQ-5D-Y-3L with Different Proxy Perspectives.

BACKGROUND AND OBJECTIVES: EQ-5D-Y-3L health states are commonly valued by asking adults to complete stated preference tasks, 'given their views about a 10-year-old child' (hereafter referred to as proxy 1). The use of this perspective has been a source of debate. In this paper, we investigated an alternative proxy perspective: i.e. adults considered what they think a 10-year old-child would decide for itself (hereafter, proxy 2 (substitute)]. Our main objective was to explore how the outcomes, dispersion and response patterns of a composite time trade-off valuation differ between proxy 1 and proxy 2. METHODS: A team of four trained interviewers completed 402 composite time trade-off interviews following the EQ-5D-Y-3L protocol. Respondents were randomly allocated to value health states in either the proxy 1 or proxy 2 (substitute) perspective. Each respondent valued ten health states with the perspective they were assigned to, as well as one health state with the alternative perspective (33333). RESULTS: The use of different proxy perspectives yielded differences in EQ-5D-Y-3L valuation. For states in which children had considerable pain and were very worried, sad or unhappy, respondents' valuations were lower in proxy 1 than in proxy 2 (substitute) perspectives, by about 0.2. Within-subject variation across health states was lower for proxy 2 (substitute) than proxy 1 perspectives. Analyses of response patterns suggest that data for proxy 2 (substitute) perspectives were less clustered. CONCLUSIONS: There are systematic differences between composite time trade-off responses given by adults deciding for children and adults considering what children would want for themselves. In addition to warranting further qualitative exploration, such differences contribute to the ongoing normative discussion surrounding the source and perspective used for valuation of child and adolescent health.

Investigating Rewards and Deposit Contract Financial Incentives for Physical Activity Behavior Change Using a Smartphone App: Randomized Controlled Trial.

BACKGROUND: Financial incentive interventions for improving physical activity have proven to be effective but costly. Deposit contracts (in which participants pledge their own money) could be an affordable alternative. In addition, deposit contracts may have superior effects by exploiting the power of loss aversion. Previous research has often operationalized deposit contracts through loss framing a financial reward (without requiring a deposit) to mimic the feelings of loss involved in a deposit contract. OBJECTIVE: This study aimed to disentangle the effects of incurring actual losses (through self-funding a deposit contract) and loss framing. We investigated whether incentive conditions are more effective than a no-incentive control condition, whether deposit contracts have a lower uptake than financial rewards, whether deposit contracts are more effective than financial rewards, and whether loss frames are more effective than gain frames. METHODS: Healthy participants (N=126) with an average age of 22.7 (SD 2.84) years participated in a 20-day physical activity intervention. They downloaded a smartphone app that provided them with a personalized physical activity goal and either required a €10 (at the time of writing: €1=US $0.98) deposit up front (which could be lost) or provided €10 as a reward, contingent on performance. Daily feedback on incentive earnings was provided and framed as either a loss or gain. We used a 2 (incentive type: deposit or reward) × 2 (feedback frame: gain or loss) between-subjects factorial design with a no-incentive control condition. Our primary outcome was the number of days participants achieved their goals. The uptake of the intervention was a secondary outcome. RESULTS: Overall, financial incentive conditions (mean 13.10, SD 6.33 days goal achieved) had higher effectiveness than the control condition (mean 8.00, SD 5.65 days goal achieved; P=.002; ηp2=0.147). Deposit contracts had lower uptake (29/47, 62%) than rewards (50/50, 100%; P<.001; Cramer V=0.492). Furthermore, 2-way analysis of covariance showed that deposit contracts (mean 14.88, SD 6.40 days goal achieved) were not significantly more effective than rewards (mean 12.13, SD 6.17 days goal achieved; P=.17). Unexpectedly, loss frames (mean 10.50, SD 6.22 days goal achieved) were significantly less effective than gain frames (mean 14.67, SD 5.95 days goal achieved; P=.007; ηp2=0.155). CONCLUSIONS: Financial incentives help increase physical activity, but deposit contracts were not more effective than rewards. Although self-funded deposit contracts can be offered at low cost, low uptake is an important obstacle to large-scale implementation. Unexpectedly, loss framing was less effective than gain framing. Therefore, we urge further research on their boundary conditions before using loss-framed incentives in practice. Because of limited statistical power regarding some research questions, the results of this study should be interpreted with caution, and future work should be done to confirm these findings. TRIAL REGISTRATION: Open Science Framework Registries osf.io/34ygt; https://osf.io/34ygt.

Correcting for discounting and loss aversion in composite time trade-off.

Time trade-off utilities have been suggested to be biased upwards. This bias is a result of the method being applied assuming linear utility of life duration, which is violated when individuals discount future life years or are loss averse for health. Applying a "corrective approach", that is, measuring individuals' discount function and loss aversion and correcting time trade-off utilities for these individual characteristics, may reduce this bias in utilities. Earlier work has developed this approach for time trade-off in a student sample. In this study, the corrective approach was extended to composite time trade-off (cTTO) methodology, which enabled correcting utilities for health states worse than dead. In digital interviews a sample of 150 members of the general public completed cTTO tasks for six health states, and afterward they completed measurements of loss aversion and discounting. cTTO utilities were corrected using these measurements under multiple specifications. Respondents were also asked to reflect on and adjust their cTTO utilities directly. Our results show considerable loss aversion and both positive and negative discounting were prevalent. As predicted, correction generally resulted in lower utilities. This was in accordance with the direction of adjustments made by respondents themselves.

Expect Nothing: The (Lack of) Influence of Subjective Life Expectancy on Valuation of Child Health States.

Objective: Earlier research has shown that individuals' subjective life expectancy (SLE) affects health state valuation with time trade-off (TTO). Individuals with longer expected life durations are less willing to trade-off life duration, which yields higher utilities. In this article, the influence of SLE is explored in the valuation of EQ-5D-Y-3L with a proxy perspective, i.e., adults' valuation of health states considering the life of a 10-year-old child. As SLE for children is likely higher, this might explain earlier findings suggesting that individuals are less willing to trade-off years of life for children than for adults. Methods: A total of 197 respondents were recruited to take part in digital TTO interviews, facilitated by trained interviewers. TTO interviews were implemented in accordance with the recommended protocol for the valuation of EQ-5D-Y-3L. Respondents valued 10 EQ-5D-Y-3L health states for a 10-year-old child, after which they were asked to report how old they themselves expected to become and also how old they expected a 10-year-old child to become. Results: Generally, adult respondents reported higher SLE for children than for themselves. Neither SLE was systematically associated with the willingness to trade lifetime or the number of life years traded off in TTO tasks. This null-result was substantiated by regression analyses per health state. Conclusion: The results of this study suggest that individuals' expectations about longevity are not associated with EQ-5D-Y-3L valuation. This lack of association is in contrast to earlier work and might be explained by the psychological distance introduced with proxy perspective valuation, or by the methodological differences with earlier work.

What Do They Know? Comparing Public Knowledge and Opinions about Rodent Management to the Expectations of Pest Controllers.

Integrated pest management (IPM) involves the control of pests, such as rodents, based on preventive measures and reduced use of chemical control. In view of the number of reported rodent infestations, it appears unlikely that the public has much knowledge about rodents. The objectives of this study were (i) to assess the knowledge and opinions of the public regarding prevention and control of rodent nuisance, and (ii) to assess whether pest controllers have an accurate idea of the knowledge and opinions of the public. The sample contained a total of 314 members of the public and 86 people working in the pest control sector. Responding members of the general public were asked about their knowledge and opinions about IPM in a questionnaire, whereas people working in the pest control sector were asked if they thought the general public had this knowledge and/or opinions. The results show that members of the public have a reasonable level of knowledge regarding preventive measures against rodents, which are part of IPM. People working in the pest control sector underestimate the public's knowledge of preventive measures, such as perimeter exclusion and hygiene measures. Such underestimation may affect their communication with (potential) clients.

Think of the Children: A Discussion of the Rationale for and Implications of the Perspective Used for EQ-5D-Y Health State Valuation.

OBJECTIVES: The recently published EQ-5D-Y valuation protocol prescribes the general public values EQ-5D-Y health states for a 10-year-old child. This child perspective differs from the individual perspective applied for valuation of adult EQ-5D instruments. This article discusses the rationale for and implications of applying a child perspective for EQ-5D-Y health state valuation. METHODS: This article was informed by an exploration of the normative and empirical literature on health state valuation. We identified and summarized key discussion points in a narrative review. RESULTS: Although valuing EQ-5D-Y health states from an individual perspective is feasible, it may be problematic for several reasons. The use of a child perspective implies that-rather than valuing one's own health-someone else's health is valued. This may require the projection of one's own beliefs, expectations, and preferences on others, which could change the decision processes underlying the elicited preferences. Furthermore, because preferences are obtained for a 10-year-old child, it is unclear if this given age as well as other (missing) information on the described child beneficiary (should) affect valuation of EQ-5D-Y health states. CONCLUSIONS: The change from an individual to a child perspective in the valuation of EQ-5D-Y will likely lead to differences in utilities. This has implications for the estimation of incremental health-related quality-of-life gains in economic evaluations of health technologies for children and adolescents and therefore might affect reimbursement decisions. Further research is necessary for gaining insight into the extent to which this impact is normatively and empirically justified.

Trust me; I know what I am doing investigating the effect of choice list elicitation and domain-relevant training on preference reversals in decision making for others.

One core assumption of standard economic theory is that an individual's preferences are stable, irrespective of the method used to elicit them. This assumption may be violated if preference reversals are observed when comparing different methods to elicit people's preferences. People may then prefer A over B using one method while preferring B over A using another. Such preference reversals pose a significant problem for theoretical and applied research. We used a sample of medical and economics students to investigate preference reversals in the health and financial domain when choosing patients/clients. We explored whether preference reversals are associated with domain-relevant training and tested whether using guided 'choice list' elicitation reduces reversals. Our findings suggest that preference reversals were more likely to occur for medical students, within the health domain, and for open-ended valuation questions. Familiarity with a domain reduced the likelihood of preference reversals in that domain. Although preference reversals occur less frequently within specialist domains, they remain a significant theoretical and practical problem. The use of clearer valuation procedures offers a promising approach to reduce preference reversals.

Time for Tele-TTO? Lessons Learned From Digital Interviewer-Assisted Time Trade-Off Data Collection.

The preferred mode of administration of time trade-off (TTO) in large-scale valuation studies is face-to-face (personal) interviews facilitated by a trained interviewer. Geographical, financial or situational constraints could complicate personal TTO interviews. When facing such constraints, the use of digital interviews, in which trained interviewers facilitate through videotelephony software (i.e. tele-TTO) may be considered. This paper aims to guide researchers in how to approach tele-TTO interviews and discusses their advantages and disadvantages. The main advantages of tele-TTO compared to personal TTO are decreased need for travel and increased flexibility of interview scheduling, which could reduce costs and may foster representative sampling. Possible disadvantages of tele-TTO are partial loss of visual cues, complications with building rapport and possible selection effects that result from differences in interview preparation. Furthermore, the paper reports on lessons learned from a project in which both personal TTO and tele-TTO interviews were conducted. The results of this project suggest that although they require a different recruitment and interview process, tele-TTO interviews are feasible and provide flexibility to the interviewer. Furthermore, tele-TTO interviews yield largely similar results. Future research should explore the role of possible selection effects and respondents' perspective on tele-TTO interviews.

What is it going to be, TTO or SG? A direct test of the validity of health state valuation.

Standard gamble (SG) typically yields higher health state valuations than time trade-off (TTO), which may be caused by biases affecting both methods. It has been suggested that TTO yields more accurate health state valuations, because TTO is subject to both upward and downward biases that may cancel out. Verifying this claim, however, would require a golden standard to test validity against. In this study, we attempted to provide a first direct test of the validity of health state valuation. A total of 119 students completed five TTO and SG tasks. Afterwards, their health state valuations elicited with TTO and SG were shown to them in an interactive graph. Respondents were asked to indicate which of the methods represented their valuation of a health state best. They could also adjust their valuation. Overall, we found that respondents indicated that TTO valuations better reflected health state valuations, a result that was more pronounced for more severe health states. When offered the opportunity, on average, respondents adjusted health state valuations downwards. These findings may have implications for future work on (bias correction in) health state valuations.

Living up to expectations: Experimental tests of subjective life expectancy as reference point in time trade-off and standard gamble.

Earlier work suggested that subjective life expectancy (SLE) functions as reference point in time trade-off (TTO), but has not tested or modelled this explicitly. In this paper we construct a model based on prospect theory to investigate these predictions more thoroughly. We report the first experimental test of reference-dependence with respect to SLE for TTO and extend this approach to standard gamble (SG). In two experiments, subjects' SLEs were used to construct different versions of 10-year TTO and SG tasks, with the gauge duration either described as occurring above or below life expectation. Our analyses suggest that both TTO and SG weights were affected by SLE as predicted by prospect theory with SLE as reference point. Subjects gave up fewer years in TTO and were less risk-tolerant in SG below SLE, implying that weights derived from these health state valuation methods for durations below SLE will be biased upwards.

Good things come to those who wait-Decreasing impatience for health gains and losses.

Historically, time preferences are modelled by assuming constant discounting, which implies a constant level of impatience. The prevailing empirical finding, however, is decreasing impatience (DI), meaning that levels of impatience decrease over time. Theoretically, such changes in impatience are crucial to understand behavior and self-control problems. Very few methods exist to measure DI without being restricted to or confounded by certain assumptions about the discounting function or utility curve. One such measure is the recently introduced DI-index, which has been applied to both monetary and health outcomes. The DI-index quantifies the deviation from constant impatience and is flexible enough to capture both increasing and decreasing impatience. In this study, we apply the DI-index to measure impatience for health outcomes in a reference-dependent framework. That is, we measure impatience for both health gains and health losses compared to a reference-point, in individual and societal settings, using a within-subjects design (n = 98). We allowed for both positive and negative discounting, since negative discounting has been observed for losses (i.e. preferring to incur losses earlier rather than later) in earlier work. To capture changes in time inconsistency when subjects show negative discounting (i.e. patience), we modify the DI-index to a decreasing (im)patience (DIP)-index, which can be applied without loss of generality. As in earlier work, we observe large heterogeneity in time consistency; i.e., a mix of decreasing, increasing and constant (im)patience. Across all DIP-indices elicited, increasing impatience was the modal preference for those satisfying impatience, and decreasing patience for those satisfying patience. No systematic differences were observed between health gains and losses or between societal and individual outcomes. This suggests that for health outcomes both patient and impatient individuals assign more importance to time differences delayed further in the future.

A comparison of individual and collective decision making for standard gamble and time trade-off.

Quality-Adjusted Life-Years (QALYs) are typically derived from individual preferences over health episodes. This paper reports the first experimental investigation into the effects of collective decision making on health valuations, using both time trade-off (TTO) and standard gamble (SG) tasks. We investigated collective decision making in dyads, by means of a mixed-subjects design where we control for learning effects. Our data suggest that collective decision making has little effect on decision quality, as no effects were observed on decision consistency and monotonicity for both methods. Furthermore, QALY weights remained similar between individual and collective decisions, and the typical difference in elicited weights between TTO and SG was not affected. These findings suggest that consulting with others has little effect on health state valuation, although learning may have. Additionally, our findings add to the literature of the effect of collective decision making, suggesting that no such effect occurs for TTO and SG.

The Corrective Approach: Policy Implications of Recent Developments in QALY Measurement Based on Prospect Theory.

BACKGROUND AND OBJECTIVES: Common health state valuation methodology, such as time tradeoff (TTO) and standard gamble (SG), is typically applied under several descriptively invalid assumptions, for example, related to linear quality-adjusted life years (QALYs) or expected utility (EU) theory. Hence, the current use of results from health state valuation exercises may lead to biased QALY weights, which may in turn affect decisions based on economic evaluations using such weights. Methods have been proposed to correct responses for the biases associated with different health state valuation techniques. In this article we outline the relevance of prospect theory (PT), which has become the dominant descriptive alternative to EU, for health state valuations and economic evaluations. METHODS AND RESULTS: We provide an overview of work in this field, which aims to remove biases from QALY weights. We label this "the corrective approach." By quantifying PT parameters, such as loss aversion, probability weighting, and nonlinear utility, it may be possible to correct TTO and SG responses for biases in an attempt to produce more valid estimates of preferences for health states. Through straightforward examples, this article illustrates the effects of this corrective approach and discusses several unresolved issues that currently limit the relevance of corrected weights for policy. CONCLUSIONS: Suggestions for research addressing these issues are provided. Nonetheless, if validly corrected health state valuations become available, we argue in favor of using these in economic evaluations.