Understanding community perception and disability weights - A qualitative exploration of reasons associated with values in two states of India

Background

Health state valuation attempts to evaluate health states based on the perception of individuals. The values are used to derive disability weights (DWs) -an important metric for estimation of disability-adjusted life years and thereby calculation of the burden of diseases. Several studies have calculated DWs using different methods of valuation, however, very few have attempted to explore the underlying cause for assigning values to different health states. This study aims to document the perceptions, preferences, and social context in assigning DWs to given health states.

Methods

A total of 42 community members and 21 service providers (from public and private sectors) across urban and rural Odisha and Telangana were interviewed between July to September 2018. A face-to-face in-depth interview and a rank ordering technique through card sort exercise was employed to explore reasons and perceptions of individuals in the context of health states using the thematic framework approach.

Findings

Six themes emerged through analysis: awareness of the health state, nature of the disease, disease consequences, treatment-related issues, social implications, and case burden. Each theme captured an individual's reason for valuing one health state as different from the other, with differences and/or similarities between community members and service providers.

Conclusion

Our study provides a comprehensive comparison between contrasting groups of individuals, thereby suggesting mere acceptance of 'experts' reasoning may not always suffice. Further research studies in the future need to be conducted for a better insight into the health perspective of a culturally diverse community. It can also help estimate the burden of disease for decision making and resource allocation in developing countries.

Methodological similarities and variations among EQ-5D-5L value set studies: a systematic review

OBJECTIVES

(1) To descriptively compare the selected elements of valuation methods for EQ-5D-5L value set studies, (2) to compare the characteristics of the value sets, and (3) to examine the associations between the selected elements of valuation methods and the EQ-5D-5L value sets.

METHODS

A systematic literature search of EQ-5D-5L valuation studies from 1 January 2009 to 22 April 2021 was conducted in selected databases. Following the initial search, we also explored additional studies published during the completion of the final version of the manuscript. Similarities and variations for selected elements of valuation methods were descriptively compared. The relative importance of dimensions, utility decrements between the levels, and distribution of the utility scores were used to compare value sets. A meta-regression analysis examined the associations between the selected methodological elements and the utility scores and dimension levels of EQ-5D-5L.

RESULTS

A total of 31 studies were included in this review. Methodological similarities centered around data collection and preference elicitation method. On the other hand, variations include sampling technique, sample size, and value set modeling. The variations in value sets based on the relative importance of dimension, decrement in utility score, and distribution of utility score across countries were observed. Although the distribution of the utility scores differed across countries, higher levels of each dimension tended to have a larger decrement in the utility scores. Mean utility scores for the experience-based value sets were higher than those estimated using stated choice methods. The selected methodological elements were not significantly associated with the mean predicted utility scores or most dimension-level coefficients.

CONCLUSIONS

EQ-5D-5L health state valuation methods and characteristics of value sets differed across studies. The impact of the variation of methodological elements on the value sets should be further investigated.

Variations in Patients' Overall Assessment of Their Health Across and Within Disease Groups Using the EQ-5D Questionnaire: Protocol for a Longitudinal Study in the Swedish National Quality Registers

BACKGROUND

EQ-5D is one of the most commonly used questionnaires to measure health-related quality of life. It is included in many of the Swedish National Quality Registers (NQRs). EQ-5D health states are usually summarized using "values" obtained from members of the general public, a majority of whom are healthy. However, an alternative, which remains to be studied in detail, is the potential to use patients' self-reported overall health on the visual analog scale (VAS) as a means of capturing experience-based perspective.

OBJECTIVE

The aim of this study is to assess EQ VAS as a valuation method with an experience-based perspective through comparison of its performance across and within patient groups, and with that of the general population in Sweden.

METHODS

Data on nearly 700,000 patients from 12 NQRs covering a variety of diseases/conditions and nearly 50,000 individuals from the general population will be analyzed. The EQ-5D-3L data from the 12 registers and EQ-5D-5L data from 2 registers will be used in the analyses. Longitudinal studies of patient-reported outcomes among different patient groups will be conducted in the period from baseline to 1-year follow-up. Descriptive statistics and analyses comparing EQ-5D dimensions and observed self-assessed EQ VAS values across and within patient groups will be performed. Comparisons of the change in health state and observed EQ VAS values at 1-year follow-up will also be undertaken. Regression models will be used to assess whether EQ-5D dimensions predict observed EQ VAS values to investigate patient value sets in each patient group. These will be compared across the patient groups and with the existing Swedish experience-based VAS and time trade-off value sets obtained from the general population.

RESULTS

Data retrieval started in May 2019 and data of patients in the 12 NQRs and from the survey conducted among the general population have been retrieved. Data analysis is ongoing on the retrieved data.

CONCLUSIONS

This research project will provide information on the differences across and within patient groups in terms of self-reported health status through EQ VAS and comparison with the general population. The findings of the study will contribute to the literature by exploring the potential of self-assessed EQ VAS values to develop value sets using an experience-based perspective.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04359628; https://clinicaltrials.gov/ct2/show/NCT04359628.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/27669.

Psychometric Evaluation of the Health State Description Questionnaire in Chile: A Proposal for a Latent Variable Approach for Valuating Health States

BACKGROUND

A few instruments that identify and valuate health states are based on the International Classification of Functioning, Disability and Health States of the World Health Organization. One of them is the Health State Description (HSD) questionnaire first used in the World Health Survey (WHS) initiative (HSD-WHS), whose psychometric properties have not been evaluated in Chile. Additionally, the use of latent variables for the valuation process of health states has been scarcely investigated in the context of population health metrics. We aim to evaluate the psychometric properties and factorial structure of the HSD-WHS for Chile and describe a latent variable method for valuating health states associated with diseases.

METHODS

We used data from the second Chilean National Health population-based survey from 2009 to 2010 (N = 5293). We explored the factorial structure of the HSD-WHS through exploratory and confirmatory factor analyses, the reliability, and the discriminant validity of the latent variable of disability. Disability weights for diseases were calculated using a linear regression model.

RESULTS

We found an adequate goodness of fit for a second-order model with 9 factors corresponding to disability domains (Tucker-Lewis index = 0.99, comparative fit index = 0.99, root mean square error of approximation = 0.060), and good reliability estimates (standardized α = 0.91). The rescaled (between 0 and 100) latent variable of disability showed significant difference according to the explored variables. We estimated disability weights for the following: (1) depressive episode, 13.6 (12.1-15.2), (2) hypertension, 1.6 (0.0-3.3), and (3) diabetes, 5.0 (2.5-7.4).

CONCLUSIONS

This study supports the use of the HSD-WHS questionnaire in the Chilean population and a latent variable approach for valuating health states associated with diseases.

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.

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.

An overview of the time trade-off method: concept, foundation, and the evaluation of distorting factors in putting a value on health

INTRODUCTION

Preference-based instruments measuring health status express the value of specific health states in a single number. One method used is time trade-off (TTO). Health-status values are key elements in calculating quality-adjusted life years (QALYs) and are pertinent for resource allocation. Since they are used in economic evaluations of healthcare, searching for a theoretical foundation of TTO in economics is justified.

AREA COVERED

This paper provides an overview of TTO, including its relation to economic theory, and discusses biases and distortions, compiled from recent and older research. Inconsistencies between TTO and random utility theory were detected; The TTO is confounded by time preferences and by respondents' life expectancies. TTO is cognitively challenging, therefore guidance during the interviews is needed, producing interview effects. TTO does not measure one thing at a time, nor are the values independent of other states that are being valued in the same task. That is, TTO does not exhibit theoretical measurement properties such as unidimensionality and the invariance principle.

EXPERT OPINION

We conclude that the TTO may be a pragmatic method of eliciting health state values, but the limitations in regard to measurement theory and practical elicitation problems makes it prone to inconsistencies and arbitrariness.

Using EQ-5D Data to Measure Hospital Performance: Are General Population Values Distorting Patients' Choices?

Background. The English National Health Service publishes hospital performance indicators based on average postoperative EQ-5D index scores after hip replacement surgery to inform prospective patients' choices of hospital. Unidimensional index scores are derived from multidimensional health-related quality-of-life data using preference weights estimated from a sample of the UK general population. This raises normative concerns if general population preferences differ from those of the patients who are to be informed. This study explores how the source of valuation affects hospital performance estimates. Methods. Four different value sets reflecting source of valuation (general population v. patients), valuation technique (visual analog scale [VAS] v. time tradeoff [TTO]), and experience with health states (currently experienced vs. experimentally estimated) were used to derive and compare performance estimates for 243 hospitals. Two value sets were newly estimated from EQ-5D-3L data on 122,921 hip replacement patients and 3381 members of the UK general public. Changes in hospital ranking (nationally) and performance outlier status (nationally; among patients' 5 closest hospitals) were compared across valuations. Results. National rankings were stable under different valuations (rank correlations >0.92). Twenty-three (9.5%) hospitals changed outlier status when using patient VAS valuations instead of general population TTO valuations, the current approach. Outlier status also changed substantially at the local level. This was explained mostly by the valuation technique, not the source of valuations or experience with the health states. Limitations. No patient TTO valuations were available. The effect of value set characteristics could be established only through indirect comparisons. Conclusion. Different value sets may lead to prospective patients choosing different hospitals. Normative concerns about the use of general population valuations are not supported by empirical evidence based on VAS valuations.

Happy with Your Capabilities? Valuing ICECAP-O and ICECAP-A States Based on Experienced Utility Using Subjective Well-Being Data

Background. The ICECAP-O and the ICECAP-A are validated capability well-being instruments. To be used in economic evaluations, multidimensional instruments require weighting of the distinguished well-being states. These weights are usually obtained through ex ante preference elicitation (i.e., decision utility) but could also be based on experienced utility. Objective. This article describes the development of value sets for ICECAP-O and ICECAP-A based on experienced utility and compares them with current decision utility weights. Methods. Data from 2 cross-sectional samples corresponding to the target groups of ICECAP-O and ICECAP-A were used in 2 separate analyses. The utility impacts of ICECAP-O and ICECAP-A levels were assessed through regression models using a composite measure of subjective well-being as a proxy for experienced utility. The observed utility impacts were rescaled to match the 0 to 1 range of the existing value set. Results. The calculated experienced utility values were similar to the decision utility weights for some of the ICECAP dimensions but deviated for others. The largest differences were found for weights of the ICECAP-O dimension enjoyment and the ICECAP-A dimensions attachment and autonomy. Conclusions. The results suggest a different weighting of ICECAP-O and ICECAP-A levels if experienced utility is used instead of decision utility.

Reasoning in the valuation of health-related quality of life: A qualitative content analysis of deliberations in a pilot study

BACKGROUND

Group deliberation can be a pathway to understanding reasons behind judgement decisions. This pilot study implemented a deliberative process to elicit public values about health-related quality of life. In this study, participants deliberated scales and weights for a German adaption of the Short-Form Six-Dimension (SF-6D) Version 2 from a public perspective.

OBJECTIVE

This article examines the reasons participants stated for health state valuations and investigates the feasibility of eliciting public reasons for judgement decisions in a deliberative setting.

METHODS

The 1-day deliberation was guided by MACBETH as a method of multi-criteria decision analysis and involved qualitative comparisons of SF-6D health states and dimensions. Participants deliberated in parallel small groups and a subsequent plenary assembly. A qualitative content analysis was conducted to assess the value judgements and reasons behind them.

RESULTS

A total of 34 students participated in the study. Common reasoning was the level of impairment, marginal benefit, possibility of adjustment and expectation satisfaction. While the small groups agreed on scales for the SF-6D dimensions, the plenary assembly did not reach consensus on one scale and dimension weights. When dimensions were prioritized, these were pain and mental health.

CONCLUSIONS

While no consented value set was derived, this pilot study presents a promising approach for eliciting public reasoning behind judgements on health state values. Furthermore, it demonstrates that participants consider diverse motives when valuing health-related quality of life.

U.K. utility weights for the EORTC QLU-C10D

The EORTC QLU-C10D is a new multi-attribute utility instrument derived from the widely used cancer-specific quality of life questionnaire, EORTC QLQ-C30. It contains 10 dimensions (physical functioning, role functioning, social functioning, emotional functioning, pain, fatigue, sleep, appetite, nausea, bowel problems), each with four levels. The aim of this study was to provide U.K. general population utility weights for the QLU-C10D. A U.K. online panel was quota-sampled to align the sample to the general population proportions of sex and age (≥18 years). The online valuation survey included a discrete choice experiment (DCE). Each participant was asked to complete 16 choice-pairs, each comprising two QLU-C10D health states plus duration. DCE data were analysed using conditional logistic regression to generate utility weights. Data from 2,187 respondents who completed at least one choice set were included in the DCE analysis. The final U.K. QLU-C10D utility weights comprised decrements for each level of each health dimension. For nine of the 10 dimensions (all except appetite), the expected monotonic pattern was observed across levels: Utility decreased as severity increased. For the final model, consistent monotonicity was achieved by merging inconsistent adjacent levels for appetite. The largest utility decrements were associated with physical functioning and pain. The worst possible health state (the worst level of each dimension) is -0.083, which is considered slightly worse than being dead. The U.K.-specific utility weights will enable cost-utility analysis (CUA) for the economic evaluation of new oncology therapies and technologies in the United Kingdom, where CUA is commonly used to inform resource allocation.

Valuing Health State: An EQ-5D-5L Value Set for Ethiopians

OBJECTIVES

There is a growing interest in health technology assessment and economic evaluations in developing countries such as Ethiopia. The objective of this study was to derive an EQ-5D-5L value set from the Ethiopian general population to facilitate cost utility analysis.

METHODS

A nationally representative sample (N = 1050) was recruited using a stratified multistage quota sampling technique. Face-to-face, computer-assisted interviews using the EuroQol Portable Valuation Technology (EQ-PVT) protocol of composite time trade-off (c-TTO) and discrete choice experiments (DCEs) were undertaken to elicit preference scores. The feasibility of the EQ-PVT protocol was pilot tested in a sample of the population (n = 110). A hybrid regression model combining c-TTO and DCE data was used to estimate the final value set.

RESULTS

In the pilot study, the acceptability of the tasks was good, and there were no special concerns with undertaking the c-TTO and DCE tasks. The coefficients generated from a hybrid model were logically consistent. The predicted values for the EQ-5D-5L ranged from -0.718 to 1. Level 5 anxiety/depression had the largest impact on utility decrement (-0.458), whereas level 5 self-care had the least impact (-0.222). The maximum predicted value beyond full health was 0.974 for the 11112 health state.

CONCLUSIONS

This is the first EQ-5D-5L valuation study in Africa using international valuation methods (c-TTO and DCE) and also the first using the EQ-PVT protocol to derive a value set. We expect that the availability of this value set will facilitate health technology assessment and health-related quality-of-life research and inform policy decision making in Ethiopia.

Effect of Reflection and Deliberation on Health State Values: A Mixed-Methods Study

BACKGROUND

Health economists ask members of the general public to value health states, but it is recognized that individuals construct their preferences during the valuation tasks. Conventional methods rely on one-off interviews that do not give participants time to reflect and deliberate on their preferences.

OBJECTIVE

This study investigates the effect of reflection and deliberation on health state preferences using the EQ-5D questionnaire and time trade-off valuation method.

METHODS

A novel concurrent explanatory mixed-methods design is used to investigate the explanation for the quantitative findings.

RESULTS

A total of 57 participants in the United Kingdom valued health states before and after a group-based deliberation exercise. There were large changes in health state values at the individual level, but the changes canceled out at the aggregate level. The mixed-methods findings suggest deliberation did not reveal new information or reduce inconsistencies in reasoning but rather focused on an exchange of personal subjective beliefs. In cases of disagreement, the participants accepted but did not adopt other participants' opinions. Participants remained uncertain about the relevance of their experiences and about their values.

CONCLUSIONS

The evidence suggests that reflection and deliberation, as designed in this study, are unlikely to result in large systematic changes of health state values. The uncertainties expressed by participants means future research should investigate whether preferences are informed or whether providing participants with more information helps them construct their preferences with more certainty. The mixed-methods design used is a promising design to help elucidate the reasons for quantitative findings.

On the Optimization of Bayesian D-Efficient Discrete Choice Experiment Designs for the Estimation of QALY Tariffs That Are Corrected for Nonlinear Time Preferences

OBJECTIVES

This article explains how to optimize Bayesian D-efficient discrete choice experiment (DCE) designs for the estimation of quality-adjusted life year (QALY) tariffs that are unconfounded by respondents' time preferences.

METHODS

The calculation of Bayesian D-errors is explained for DCE designs that allow for the disentanglement of respondents' time and health-state preferences. Time preferences are modelled via an exponential, hyperbolic, or power discount function and the performance of the proposed DCE designs is compared with that of several conventional DCE designs that do not take nonlinear time preferences into account.

RESULTS

Based on the achieved D-error, asymptotic standard error, and estimated sample size to obtain statistically significant estimates of the discount rate parameters, the proposed designs outperform the conventional DCE designs.

CONCLUSIONS

We recommend that applied researchers use appropriately optimized DCE designs for the estimation of QALY tariffs that are corrected for time preferences. The TPC-QALY software package that accompanies this article makes the recommended designs easily accessible for health-state valuation researchers.

Describing the Development of a Health State Valuation Protocol to Obtain Community-Derived Disability Weights

For the prioritization of the allocation of national resources, estimating the burden of disease studies play a critical role. Hence the first Global Burden of Disease study conducted in the 1990s was done for this particular estimation. By the means of introducing disability-adjusted life year (DALY) metric, the burden of various diseases was calculated using disability weights (DWs)—a component of DALY. DWs are values that capture individuals' perception regarding the severity of diseases that involve valuation tools and health state descriptions. Various studies have been conducted over the past few decades to evaluate health states and derive disease-specific disability weights using Person-Trade off, Time-trade off, etc. However, use of these complex and cognitively demanding methods has been carried out in developed countries where the bulk of the populace is more educated. Few attempts have been made in low- and middle-income countries such as India, where not only the majority is less educated but also the social construction of diseases and health conditions are diverse. Therefore, due to the absence of methodological protocols of health state valuations for application at the community-level in the developing world, we attempted to systematically describe the procedure that can be used universally and cross-culturally for various health states. We began with the tentative selection of health states and health states valuation methods by conducting a meticulous literature review, followed by community exploration and medical consultations. This led to developing vignettes (clinical description) and 6D5L pictorial narrations (functional status description). Two field tests for checking the usability and refinement of the tools was done. Final consultation by an expert panel comprising of medical and non-medical professionals was held/conducted to finalize the health state labels and functional status profiles of each health state. The methodical approach provides a robust and thorough procedure for guiding researchers to implement health state valuation studies at community level.

Exclusion Criteria as Measurements I: Identifying Invalid Responses

Background. In a systematic review, Engel et al. found large variation in the exclusion criteria used to remove responses held not to represent genuine preferences in health state valuation studies. We offer an empirical approach to characterizing the similarities and differences among such criteria. Setting. Our analyses use data from an online survey that elicited preferences for health states defined by domains from the Patient-Reported Outcomes Measurement Information System (PROMIS^®), with a U.S. nationally representative sample (N = 1164). Methods. We use multidimensional scaling to investigate how 10 commonly used exclusion criteria classify participants and their responses. Results. We find that the effects of exclusion criteria do not always match the reasons advanced for applying them. For example, excluding very high and very low values has been justified as removing aberrant responses. However, people who give very high and very low values prove to be systematically different in ways suggesting that such responses may reflect different processes. Conclusions. Exclusion criteria intended to remove low-quality responses from health state valuation studies may actually remove deliberate but unusual ones. A companion article examines the effects of the exclusion criteria on societal utility estimates.

Exclusion Criteria as Measurements II: Effects on Utility Functions

Background. Researchers often justify excluding some responses in studies eliciting valuations of health states as not representing respondents' true preferences. Here, we examine the effects of applying 8 common exclusion criteria on societal utility estimates. Setting. An online survey of a US nationally representative sample (N = 1164) used the standard gamble method to elicit preferences for health states defined by 7 health domains from the Patient-Reported Outcomes Measurement Information System (PROMIS^®). Methods. We estimate the impacts of applying 8 commonly used exclusion criteria on mean utility values for each domain, using beta regression, a form of analysis suited to double-bounded scales, such as utility. Results. Exclusion criteria have varied effects on the utility functions for the different PROMIS health domains. As a result, applying those criteria would have varied effects on the value of treatments (and side effects) that change health status on those domains. Limitations. Although our method could be applied to any health utility judgments, the present estimates reflect the features of the study that produced them. Those features include the selected health domains, standard gamble method, and an online format that excluded some groups (e.g., visually impaired and illiterate individuals). We also examined only a subset of all possible exclusion criteria, selected to represent the space of possibilities, as characterized in a companion article. Conclusions. Exclusion criteria can affect estimates of the societal utility of health states. We use those effects, in conjunction with the results of the companion article, to make suggestions for selecting exclusion criteria in future studies.

QALYs without bias? Nonparametric correction of time trade-off and standard gamble weights based on prospect theory

Common health state valuation methodologies, such as standard gamble (SG) and time trade-off (TTO), typically produce different weights for identical health states. We attempt to alleviate these differences by correcting the confounding influences modeled in prospect theory: loss aversion and probability weighting. Furthermore, we correct for nonlinear utility of life duration. In contrast to earlier attempts at correcting TTO and SG weights, we measure and correct all these tenets simultaneously, using newly developed nonparametric methodology. These corrections were applied to three less-than-perfect health states, measured with TTO and SG. We found considerable loss aversion and probability weighting for both gains and losses in life years, and we observe concave utility for gains and convex utility for losses in life years. After correction, the initially significant differences in weights between TTO and SG disappeared for all health states. Our findings suggest new opportunities to account for bias in health state valuations but also the need for further validation of resulting weights.

Valuing Health States in Russia: A First Feasibility Study

OBJECTIVE

The aim of this study was to explore the feasibility of different health-related quality-of-life valuation methods in a new setting. Based on a small feasibility study of 100 young Russians, we trialed different methodologies and identified key differences that have implications for the development of health technology assessment in Russia.

METHODS

In face-to-face interviews, respondents completed a series of health self-assessments based on a modified version of the EQ-5D-3L, visual analogue scale, time tradeoff, standard gamble, and best-worst scaling methodologies, covering actual and hypothetical health states.

RESULTS

We found that (1) the visual analogue scale produced lower health valuations and fewer logical inconsistencies than either time trade-off or standard gamble methodologies; (2) initial health states can be decisive in determining values assigned to health improvements; (3) respondents evaluate abstract health states more positively than their own actual health states; (4) there is evidence consistent with the hypothesis that actual and hypothetical health state valuation, using EQ-5D-3L, is an artifact of understanding rather than preference and that the incorporation of additional levels may therefore be no panacea if the dimensions themselves overlook important attributes; and (5) the country context is important in determining how respondents relate to the survey tools and how those survey tools are translated and delivered.

CONCLUSIONS

Russia is commencing its health technology assessment journey and should proceed cautiously as it moves toward the valuation of health benefits. These results suggest a useful framework for a more in-depth development of health valuation methodologies in Russia.

Manipulating the 5 Dimensions of the EuroQol Instrument: The Effects on Self-Reporting Actual Health and Valuing Hypothetical Health States

Background. The EQ-5D instrument has 5 dimensions. This article reports on the effects of manipulating a) the order in which the 5 dimensions are presented (appearing first v. last), b) splitting of the composite dimensions ("pain or discomfort" and "anxiety or depression"), and c) removing or "bolting off" 1 of the 5 EQ-5D dimensions at a time. The effects were examined in 2 contexts: 1) self-reporting health and 2) health state valuations. Methods. Three different types of discrete choice experiments (DCE) including a duration attribute were designed. An online survey with 12 subtypes, each with 10 DCE tasks, was designed and completed by 2494 members of the UK general public. Results. Of the 3 manipulations in the self-reporting context, only b) splitting anxiety or depression had a significant effect. In the health state valuation context, b) splitting level 5 pain or discomfort (relative to pain) and splitting level 5 anxiety or depression (relative to anxiety) had significant effects as did c) bolting off dimensions. Conclusions. We find that the values given to certain health dimensions are sensitive to the way in which it is described and the other health dimensions presented. Of particular interest is the effect of splitting composite dimensions: a given EQ-5D(-5L) profile may mean different things depending on whether the profile is used to self-report one's health or to value hypothetical states, so that the health state values of EQ-5D(-5L) in population tariffs may not correspond to the states that patients self-report themselves in.

Advocating a Paradigm Shift in Health-State Valuations: The Estimation of Time-Preference Corrected QALY Tariffs

BACKGROUND

Despite evidence of nonproportional trade-offs in time trade-off exercises and the explicit incorporation of exponential discounting in health technology assessment calculations, quality-adjusted life-year (QALY) tariffs are currently still established under the assumption of linear time preferences.

OBJECTIVES

The aim of this study was to introduce a general method of accommodating for nonlinear time preferences in discrete choice experiment (DCE) duration studies and to evaluate its impact on estimated QALY tariffs.

METHODS

A parsimonious utility function is proposed that accommodates any discounting function and preserves linear time preferences as a special case. Based on an efficient DCE design and 1775 respondents from a nationally representative scientific household panel, preferences and QALY tariffs for the Dutch SF-6D were estimated while accommodating for nonlinear time preferences via exponential and hyperbolic discounting functions.

RESULTS

When the discount rate was estimated directly, we found strong evidence of nonlinear time preferences (with an exponential and hyperbolic discount rate of 5.7% and 16.5%, respectively). When the discount rate was estimated as a function of health state severity, we found that years lived in better health states are discounted minus years lived in impaired health states. Finally, the best statistical fit was obtained when using a hyperbolic discount function, which resulted in smaller QALY decrements and fewer health states classified as worse than immediate death.

CONCLUSIONS

Our results highlight the relevance and even necessity of a paradigm shift in health valuation studies in favor of time-preference corrected QALY tariffs, with potentially important implications for health technology assessment calculations and regulatory decisions.

Test-Retest Reliability of Discrete Choice Experiment for Valuations of QLU-C10D Health States

BACKGROUND

Recently, a newly developed cancer-specific multiattribute utility instrument based on the widely used health-related quality of life instrument, the European Organisation for Research and Treatment of Cancer QLQ-C30, was introduced: the QLU-C10D. For the elicitation of utility weights, a discrete choice experiment (DCE) was designed. Our aim was to investigate the DCE in terms of individual choice consistency and utility estimate consistency by applying a test-retest design.

METHODS

We conducted the study in general population samples in Germany and France. The DCE was administered via a web-based self-complete survey using online panels. Respondents were presented 16 choice sets comprising 11 attributes with 4 levels each. Retest was conducted 4 to 6 weeks after first assessment. We used kappa and percentage agreement as measures of choice consistency and both intraclass correlations and mean utility differences as measures of utility estimate consistency.

RESULTS

A total of 300 German respondents (31% female, mean age 48 years [SD 14]) and 305 French respondents (46% female, mean age 47 years [SD 16]) completed test and retest assessments. Individual choice consistency was moderate to high (Germany: κ = 0.605, percentage agreement = 80.2%; France: κ = 0.411, percentage agreement = 70.6%). Utility estimate consistency was high when considering intraclass correlations (all >0.79). Mean utility differences were 0.08 in the German sample and 0.05 in the French sample.

CONCLUSIONS

Results indicate that the designed DCE elicits stable health state preferences rather than guesses or mood-specific or condition-specific judgments. Nevertheless, the identified mean utility differences between test and retest need to be taken into account when determining minimal important differences for the QLU-C10D in future research.

Are Health State Valuations from the General Public Biased? A Test of Health State Reference Dependency Using Self-assessed Health and an Efficient Discrete Choice Experiment

Health state valuations of patients and non-patients are not the same, whereas health state values obtained from general population samples are a weighted average of both. The latter constitutes an often-overlooked source of bias. This study investigates the resulting bias and tests for the impact of reference dependency on health state valuations using an efficient discrete choice experiment administered to a Dutch nationally representative sample of 788 respondents. A Bayesian discrete choice experiment design consisting of eight sets of 24 (matched pairwise) choice tasks was developed, with each set providing full identification of the included parameters. Mixed logit models were used to estimate health state preferences with respondents' own health included as an additional predictor. Our results indicate that respondents with impaired health worse than or equal to the health state levels under evaluation have approximately 30% smaller health state decrements. This confirms that reference dependency can be observed in general population samples and affirms the relevance of prospect theory in health state valuations. At the same time, the limited number of respondents with severe health impairments does not appear to bias social tariffs as obtained from general population samples. Copyright © 2016 John Wiley & Sons, Ltd.

How Should Discrete Choice Experiments with Duration Choice Sets Be Presented for the Valuation of Health States?

BACKGROUND

Discrete Choice Experiments including duration (DCE_TTO) can be used to generate utility values for health states from measures such as EQ-5D-5L. However, methodological issues concerning the optimum way to present choice sets remain. The aim of the present study was to test a range of task presentation approaches designed to support the DCE_TTO completion process.

METHODS

Four separate presentation approaches were developed to examine different task features including dimension level highlighting, and health state severity and duration level presentation. Choice sets included 2 EQ-5D-5L states paired with 1 of 4 duration levels, and a third "immediate death" option. The same design, including 120 choice sets (developed using optimal methods), was employed across all approaches. The online survey was administered to a sample of the Australian population who completed 20 choice sets across 2 approaches. Conditional logit regression was used to assess model consistency, and scale parameter testing investigated poolability.

RESULTS

Overall 1,565 respondents completed the survey. Three approaches, using different dimension level highlighting techniques, produced mainly monotonic coefficients that resulted in a larger disutility as the severity level increased (excepting usual activities levels 2/3). The fourth approach, using a level indicator to present the severity levels, has slightly more non-monotonicity and produced larger ordered differences for the more severe dimension levels. Scale parameter testing suggested that the data cannot be pooled.

CONCLUSIONS

The results provide information regarding how to present DCE tasks for health state valuation. The findings improve our understanding of the impact of different presentation approaches on valuation, and how DCE questions could be presented to be amenable to completion. However, it is unclear if the task presentation impacts online respondent engagement.

Valuing Health Using Time Trade-Off and Discrete Choice Experiment Methods: Does Dimension Order Impact on Health State Values?

BACKGROUND

Health states defined by multiattribute instruments such as the EuroQol five-dimensional questionnaire with five response levels (EQ-5D-5L) can be valued using time trade-off (TTO) or discrete choice experiment (DCE) methods. A key feature of the tasks is the order in which the health state dimensions are presented. Respondents may use various heuristics to complete the tasks, and therefore the order of the dimensions may impact on the importance assigned to particular states.

OBJECTIVE

To assess the impact of different EQ-5D-5L dimension orders on health state values.

METHODS

Preferences for EQ-5D-5L health states were elicited from a broadly representative sample of members of the UK general public. Respondents valued EQ-5D-5L health states using TTO and DCE methods across one of three dimension orderings via face-to-face computer-assisted personal interviews. Differences in mean values and the size of the health dimension coefficients across the arms were compared using difference testing and regression analyses.

RESULTS

Descriptive analysis suggested some differences between the mean TTO health state values across the different dimension orderings, but these were not systematic. Regression analysis suggested that the magnitude of the dimension coefficients differs across the different dimension orderings (for both TTO and DCE), but there was no clear pattern.

CONCLUSIONS

There is some evidence that the order in which the dimensions are presented impacts on the coefficients, which may impact on the health state values provided. The order of dimensions is a key consideration in the design of health state valuation studies.

Using the Analytic Hierarchy Process to Derive Health State Utilities from Ordinal Preference Data

BACKGROUND

The EuroQol five-dimensional questionnaire is a standardized instrument used in the economic evaluation of health care to measure health state preferences across disease groups. A time trade-off (TTO) approach is commonly used to elicit preferences from the public. However, there are issues regarding how best to measure worse-than-dead states; at present, extreme valuations are rounded up to more acceptable values. TTO elicitation is also cognitively demanding for respondents and is therefore expensive to investigate.

OBJECTIVES

To describe how the analytic hierarchy process approach could be used to generate utilities from the ordinal relationships between the health states instead of the ordinal relationships between health states, allowing potentially useful preference data to be incorporated rather than excluded as they are at present. It was applied to the Measurement and Valuation of Health study data set, measuring health state preferences for the United Kingdom.

METHODS

The analytic hierarchy process approach was explained. Five approaches to structure pairwise comparisons of health state preference were described (two concave, two convex, and one linear).

RESULTS

All approaches described predicted the rankings of health states well. However, utilities derived followed an unconventional, bunched shape compared with the original Measurement and Valuation of Health TTO study. An approach was identified by optimizing the parameters, minimizing the sum of squared errors between the ordinal "health state ranking" approach and the original TTO-derived utilities.

CONCLUSIONS

This approach outlined offers the potential to convert ordinal preference data into cardinal utilities. It is simpler than TTO studies to carry out and removes the need to directly alter results of the preference ranking exercise.

Exclusion Criteria in National Health State Valuation Studies: A Systematic Review

BACKGROUND

Health state valuation data are often excluded from studies that aim to provide a nationally representative set of values for preference-based health-related quality of life (HRQoL) instruments. The purpose was to provide a systematic examination of exclusion criteria used in the derivation of societal scoring algorithms for preference-based HRQoL instruments.

METHODS

Data sources included MEDLINE, official instrument websites, and publication reference lists. Analyses that used data from national valuation studies and reported a scoring algorithm for a generic preference-based HRQoL instrument were included. Data extraction included exclusion criteria and associated justifications, exclusion rates, the characteristics of excluded respondents, and analyses that explored consequential implications of exclusion criteria on the respective national tariff.

RESULTS

Seventy-six analyses (from 70 papers) met the inclusion criteria. In addition to being excluded for logical inconsistencies, respondents were often excluded if they valued fewer than 3 health states or if they gave the same value to all health states. Numerous other exclusion criteria were identified, with varying degrees of justification, often based on an assumption that respondents did not understand the task or as a consequence of the chosen statistical modeling techniques. Rates of exclusion ranged from 0% to 65%, with excluded respondents more likely to be older, less educated, and less healthy. Limitations included that the database search was confined to MEDLINE; study selection focused on national valuation studies that used standard gamble, time tradeoff, and/or visual analog scale techniques; and only English-language studies were included.

CONCLUSION

Exclusion criteria used in national valuation studies vary considerably. Further consideration is necessary in this important and influential area of research, from the design stage to the reporting of results.

An exploratory study to test the impact on three "bolt-on" items to the EQ-5D

BACKGROUND

Generic preference-based measures were criticized for being inappropriate in some conditions. One solution is to include "bolt-on" dimensions describing additional specific health problems.

OBJECTIVES

This study aimed to develop bolt-on dimensions to the EuroQol five-dimensional questionnaire (EQ-5D) and assess their impact on health state values.

METHODS

Bolt-on dimensions were developed for vision problems, hearing problems, and tiredness. Each bolt-on dimension had three severity levels to match the EQ-5D. Three "core" EQ-5D states across a range of severity were selected, and each level of a bolt-on item was added, resulting in nine states in each condition. Health states with and without the bolt-on dimensions were valued by 300 members of the UK general public using time trade-off in face-to-face interviews, and mean health state values were compared using t tests. Regression analysis examined the impact of the bolt-on variants and the level of the bolt-on items after controlling for sociodemographic characteristics.

RESULTS

Bolt-on dimensions had an impact on health state values of the EQ-5D; however, the size, direction, and significance of the impact depend on the severity of the core EQ-5D state and of the bolt-on dimension. Regression analysis demonstrated that after controlling for possible differences in sociodemographic characteristics between the groups, there were no significant differences in health state values between the three bolt-on dimensions but confirmed that the impact depended on the severity of the EQ-5D health state and the levels of bolt-on dimensions.

CONCLUSIONS

The impact of a bolt-on dimension on the EQ-5D depends on the core health state and the level of the bolt-on dimension. Further research in this area is encouraged.

Development of an EORTC-8D utility algorithm for Sri Lanka

BACKGROUND

Currently there are no reported cancer-specific health state valuations in low- and middle-income countries using a validated preference-based measure. The EORTC-8D, a cancer-specific preference-based measure, has 81,920 health states and is useful for economic evaluations in cancer care. The aim of this study was to develop a utility algorithm to value EORTC-8D health states using preferences derived from a representative population sample in Sri Lanka.

METHODS

The time-tradeoff method was used to elicit preferences from a general population sample of 780 in Sri Lanka. A block design of 85 health states, with a time horizon of 10 years, was used for the direct valuation. Data were analyzed using generalized least squares with random effects. All respondents with at least one logical inconsistency were excluded from the analysis.

RESULTS

After logical inconsistencies were excluded, 4520 observations were available from 717 respondents for the analysis. The preferred model specified main effects with an interaction term for any level 4 or worse descriptor within a health state. Worsening of physical functioning had a substantially greater utility decrement than any other dimension in this population. Limitations are that the data collection could not include the whole country and that females formed a large part of the sample.

CONCLUSIONS

Preference weights for EORTC-8D health states for Sri Lanka have been derived: These will be very useful in economic evaluations of cancer-related interventions in a range of low- and middle-income countries.

Study protocol for valuing EQ-5D-3L and EORTC-8D health states in a representative population sample in Sri Lanka

BACKGROUND

Economic evaluations to inform decisions about allocation of health resources are scarce in Low and Middle Income Countries, including in Sri Lanka. This is in part due to a lack of country-specific utility weights, which are necessary to derive appropriate Quality Adjusted Life Years. The EQ-5D-3 L, a generic multi-attribute instrument (MAUI), is most widely used to measure and value health states in high income countries; nevertheless, the sensitivity of generic MAUIs has been criticised in some conditions such as cancer. This article describes a protocol to produce both a generic EQ-5D-3 L and cancer specific EORTC-8D utility index in Sri Lanka.

METHOD

EQ-5D-3 L and EORTC-8D health states will be valued using the Time Trade-Off technique, by a representative population sample (n = 780 invited) identified using stratified multi-stage cluster sampling with probability proportionate to size method. Households will be randomly selected within 30 clusters across four districts; one adult (≥ 18 years) within each household will be selected using the Kish grid method.Data will be collected via face-to-face interview, with a Time Trade-Off board employed as a visual aid. Of the 243 EQ-5D-3 L and 81,290 EORTC-8D health states, 196 and 84 respectively will be directly valued. In EQ-5D-3 L, all health states that combine level 3 on mobility with either level 1 on usual activities or self-care were excluded. Each participant will first complete the EQ-5D-3 L, rank and value 14 EQ-5D-3 L states (plus the worst health state and "immediate death"), and then rank and value seven EORTC-8D states (plus "immediate death"). Participant demographic and health characteristics will be also collected.Regression models will be fitted to estimate utility indices for EQ-5D-3 L and EORTC-8D health states for Sri Lanka. The dependent variable will be the utility value. Different specifications of independent variables will be derived from the ordinal EQ-5D-3 L to test for the best-fitting model.

DISCUSSION

In Sri Lanka, a LMIC health state valuation will have to be carried out using face to face interview instead of online methods. The proposed study will provide the first country-specific health state valuations for Sri Lanka, and one of the first valuations to be completed in a South Asian Country.

Health state valuation in low- and middle-income countries: a systematic review of the literature

OBJECTIVE

Cost-utility analysis is widely used in high-income countries to inform decisions on efficient health care resource allocation. Cost-utility analysis uses the quality-adjusted life-year as the outcome measure of health. High-income countries have undertaken health state valuation (HSV) studies to determine country-specific utility weights to facilitate valuation of health-related quality of life. Despite an evident need, however, the extent of HSVs in low- and middle-income countries (LMICs) is unclear.

METHODS

The literature was searched systematically by using four databases and additional Web searches to identify HSV studies carried out in LMICs. The Preferred Reporting System for Systematic Reviews and Meta-Analysis (PRISMA) strategy was followed to ensure systematic selection of the articles.

RESULTS

The review identified 17 HSV studies from LMICs. Twelve studies were undertaken in upper middle-income countries, while lower middle- and low-income countries contributed three and two studies, respectively. There were 7 generic HSV and 10 disease-specific HSV studies. The seven generic HSVs included five EuroQol five-dimensional questionnaire, one six-dimensional health state short form (derived from short-form 36 health survey), and one Assessment of Quality of Life valuations. Time trade-off was the predominant valuation method used across all studies.

CONCLUSIONS

This review found that health state valuations from LMICs are uncommon and utility weights are generally unavailable for these countries to carry out health economic evaluation. More HSV studies need to be undertaken in LMICs to facilitate efficient resource allocation in their respective health systems.

Time trade-off: one methodology, different methods

There is no scientific consensus on the optimal specification of the time trade-off (TTO) task. As a consequence, studies using TTO to value health states may share the core element of trading length of life for quality of life, but can differ considerably on many other elements. While this pluriformity in specifications advances the understanding of TTO from a methodological point of view, it also results in incomparable health state values. Health state values are applied in health technology assessments, and in that context comparability of information is desired. In this article, we discuss several alternative specifications of TTO presented in the literature. The defining elements of these specifications are identified as being either methodological, procedural or analytical in nature. Where possible, it is indicated how these elements affect health state values (i.e., upward or downward). Finally, a checklist for TTO studies is presented, which incorporates a list of choices to be made by researchers who wish to perform a TTO task. Such a checklist enables other researchers to align methodologies in order to enhance the comparability of health state values.

Effect of adding a sleep dimension to the EQ-5D descriptive system: a "bolt-on" experiment

BACKGROUND AND OBJECTIVE

The generic preference-based measures (GPBMs) of health have been widely used to obtain health utility scores for calculating quality-adjusted life-years (QALYs) for economic evaluations. It has been recognized that GPBMs may miss relevant or important dimensions of health for some specific medical conditions. The objective of this study is to explore the effect of extending the current EQ-5D descriptive system by adding a sleep dimension.

METHODS

A new instrument, EQ-5D+Sleep, is proposed by adding a sleep dimension to the EQ-5D. Based on an orthogonal design, 18 EQ-5D+Sleep states and EQ-5D states were selected and a valuation study was undertaken whereby 160 members of the generic public in South Yorkshire, UK, were interviewed using time tradeoff (TTO). Econometric models have been fitted to the data. Two null hypotheses were tested: 1) the coefficient for the sleep dimension is not significant; and 2) the inclusion of the sleep dimension has no impact on the way people value the original dimensions of EQ-5D.

RESULTS

and

CONCLUSIONS

The results support these two null hypotheses. There seems to be no benefit to adding a sleep dimension to the EQ-5D. Research is required to explore the method of adding dimensions to existing descriptive systems of health.

Binary choice health state valuation and mode of administration: head-to-head comparison of online and CAPI

BACKGROUND

Health state valuation exercises can be conducted online, but the quality of data generated is unclear.

OBJECTIVE

To investigate whether responses to binary choice health state valuation questions differ by administration mode: online versus face to face.

METHODS

Identical surveys including demographic, self-reported health status, and seven types of binary choice valuation questions were administered in online and computer-assisted personal interview (CAPI) settings. Samples were recruited following procedures employed in typical online or CAPI studies. Analysis included descriptive comparisons of the distribution of responses across the binary options and probit regression to explain the propensity to choose one option across modes of administration, controlling for background characteristics.

RESULTS

Overall, 422 (221 online; 201 CAPI) respondents completed a survey. There were no overall age or sex differences. Online respondents were educated to a higher level than were the CAPI sample and general population, and employment status differed. CAPI respondents reported significantly better general health and health/life satisfaction. CAPI took significantly longer to complete. There was no effect of the mode of administration on responses to the valuation questions, and this was replicated when demographic differences were controlled.

CONCLUSIONS

The findings suggest that both modes may be equally valid for health state valuation studies using binary choice methods (e.g., discrete choice experiments). There are some differences between the observable characteristics of the samples, and the groups may differ further in terms of unobservable characteristics. When designing health state valuation studies, the advantages and disadvantages of both approaches must be considered.

The duration effect: a link between TTO and VAS values

The value of a health state may depend on how long an individual has had to endure the health state (i.e. hedonic load). In this paper, we test the constant proportionality (CP) assumption and determine the sign of relationship between duration and health state value for 42 health states using the nationally representative data from the United Kingdom Measurement and Valuation of Health study. The results reject the CP assumption and suggest that the relationship is negative for optimal health (i.e. fair innings argument) and that the relationship is positive for poorer health states (i.e. adaptation). We find no evidence of the maximum endurable time hypothesis using these data. This evidence on the duration effect has important implications for outcomes research and the economic evaluation of interventions.