Quality Control Process for EQ-5D-5L Valuation Studies

A French Value Set for the EQ-5D-5L

OBJECTIVE

The objective of this study was to develop a French value set for the EQ-5D-5L, for academic and clinical research, and for regulatory requirements for price-setting of drugs and medical devices.

METHOD

This study used the standardized valuation protocol developed by EuroQol, using computer-assisted personal interview software. A representative sample of 1048 French residents were interviewed by a market research company, under the supervision of the research team. Health states were valued using composite time trade-off and a discrete choice experiment. Modeling was used to create values for the 3125 possible health states. The composite time trade-off data were modeled using a Tobit model with censored observations at -1 and correcting for heteroscedasticity. A conditional logit model was used for the discrete choice results, and both models were combined using a hybrid model. An adjusted hybrid model was tested to correct for imbalance in the sample on age and sex compared with the general population. A comparison with the 3-level (3L) value set was performed.

RESULTS

The adjusted model was preferred to comply with the representativeness of the general population. It provided a value set for which all coefficients were logically consistent. Values ranged from - 0.525 to 1. The distribution of values presented a shift towards higher values versus the 3L value set. Ranking of dimensions changed. Pain and discomfort and mobility were the dimensions with the highest potential for disutility compared with mobility and self-care for the 3L instrument.

CONCLUSIONS

This study provides a value set based on societal preferences of the French population, using an improved descriptive instrument of health-related quality-of-life health states. It will contribute to improve the quality of cost-effectiveness analysis in the French context and help stimulate disease-specific quality-of-life references for academic-, institutional-, and industry-promoted studies.

Rehabilitation coordinator intervention versus control in psychiatric specialist care for return to work and reduced sick leave: study protocol of a randomised controlled trial

Background

Mental disorders are the most common reason for sick leave in Sweden. Knowledge about effective methods to help these individuals to return to work (RTW)/entry into work or studies is limited. Rehabilitation coordinators (RC’s) have been introduced within healthcare with the purpose to promote cooperation, streamline the sick leave and rehabilitation process, and facilitate RTW for sick-listed patients. The function of RC’s has shown positive results by reducing sick leave within primary healthcare. However, the function has not been evaluated in terms of specialist psychiatry. This paper describes the design of a study to evaluate effects of a RC intervention on sick leave and RTW/entry in work or studies in patients with moderate to severe affective and/or moderate to severe anxiety disorders within specialist psychiatric care.

Methods

A randomised controlled trial (RCT) comparing an intervention group receiving support from a RC with a control group receiving treatment as usual (TAU). The target group is patients on sick leave, treated for affective and/or anxiety disorder, aged 25–64, with or without employment.

Discussion

This study gives the possibility to evaluate a RC intervention for individuals with mental disorders. If the study has promising vocational outcomes, it may be of importance for the participants in many ways, e.g. increase participation in society, provide economic benefits and improve health and wellbeing. This would be valuable for the individual as well as for the society.

Trial registration

The study is registered at the Clinicaltrials.gov Register Platform (ID NCT03729050) in 2 November 2018.

A Head-On Ordinal Comparison of the Composite Time Trade-Off and the Better-Than-Dead Method

OBJECTIVES

The valuation of health states worse than dead is challenging. Currently used time trade-off methods face problems in (1) detecting time-dependent preferences and (2) insensitivity toward severity for states worse than dead. The better-than-dead (BTD) method has the potential to detect time-dependent preferences. This study compares the BTD and composite time trade-off (cTTO) methods at the ordinal level.

METHODS

An experiment was conducted in a convenience sample in which respondents (N = 200) valued the same set of 7 health states in the BTD method and cTTO method. Binary BTD responses were used, with response categories of better than dead and worse than dead. Ternary cTTO responses were used, with the additional equal-to-dead response category. Polychoric correlations were used to determine the agreement between these methods. Consistency and test-retest reliability were assessed within methods.

RESULTS

Overall agreement between the cTTO and BTD method equaled 77.1% and differed between health states and respondents. For both methods, there were few inconsistencies, and the test-retest reliability was comparable (88%). Health states were more often considered worse than dead in the BTD method (BTD: 54.7%, cTTO: 37.2%).

CONCLUSIONS

The high agreement between both methods and the comparable amount of inconsistencies and test-retest reliability suggest that the methods have similar measurement properties. The BTD method yielded higher frequencies of worse-than-dead responses while essentially asking respondents to make similar choices. This accounts for part of the disagreement between the methods. Several explanations are offered for this difference, yet more research is needed to explain this phenomenon.

A new tool for creating personal and social EQ-5D-5L value sets, including valuing 'dead'

The EuroQol Group's health descriptive systems, the EQ-5D-3L and its successor introduced in 2009, the EQ-5D-5L, are widely used worldwide for valuing health-related quality of life for cost-utility analysis and patient-reported health outcome measures. A new online tool for creating personal and social EQ-5D-5L value sets was recently developed and trialled in New Zealand (NZ). The tool, which includes extensive checks of the quality of participants' data, implements the PAPRIKA method - a novel type of adaptive discrete choice experiment in the present context - and a binary search algorithm to identify any health states worse than dead. After development and testing, the tool was distributed in an online survey in February and March 2018 to a representative sample of NZ adults (N = 5112), whose personal value sets were created. The tool's extensive data quality checks resulted in a 'high-quality' sub-sample of 2468 participants whose personal value sets were, in effect, averaged to create a social value set for NZ. These results overall as well as feedback from participants indicates that the new valuation tool is feasible and acceptable to participants, enabling valuation data to be relatively easily and cheaply collected. The tool could also be used in other countries, tested against other methods for creating EQ-5D-5L value sets, applied in personalised medicine and adapted to create value sets for other health descriptive systems.

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.

Toward a Smaller Design for EQ-5D-5L Valuation Studies

BACKGROUND

To construct an EQ-5D-5L value set, the EuroQol Group developed a standard protocol named EuroQol Valuation Technology (EQ-VT), prescribing the valuation of 86 health states utilizing the composite time trade-off (cTTO) approach, and subsequently modeled the observed values to yield values for all 3125 states.

OBJECTIVE

A recent study demonstrated that a 25-state orthogonal design could provide as accurate predictions as the EQ-VT design applying visual analogue scale data. We aimed to test that design using time trade-off (TTO) data.

METHOD

We collected TTO values utilizing EQ-VT, orthogonal, and D-efficient designs. The EQ-VT design included 86 health states distributed over 3 blocks of 30 states with some duplicates. The orthogonal and D-efficient designs each comprised 1 block of 30 states. A total of 525 university students were asked to value a random block of health states using EQ-PVT (a PowerPoint replica of EQ-VT software), which generated 100 observations per health state in all 3 designs. We modeled data by design and compared the root mean square error (RMSE) between observed and predicted values within and across the designs.

RESULTS

The EQ-VT design had the lowest RMSE of 0.052; the RMSEs for the orthogonal and the D-efficient designs were 0.066 and 0.063, respectively. RMSE results between designs differed for more severe health states. Some coefficients differed between designs.

CONCLUSION

Smaller designs did not lead to significant increases in prediction errors when modeling TTO data (measuring 0.01 on a utility scale). Resource-constrained countries may use small designs for valuation studies, especially when other types of preference data, such as those from discrete choice experiments, are collected and modeled jointly.

Valuation of EQ-5D-5L Health States in Poland: the First EQ-VT-Based Study in Central and Eastern Europe

OBJECTIVE

Cost-utility analyses are becoming increasingly important in Central and Eastern Europe. We aimed to develop a Polish utility tariff for EQ-5D-5L health states.

METHODS

Face-to-face, computer-assisted interviews were collected in a representative sample. Each respondent followed a standardised protocol to collect ten composite time trade-off and seven discrete choice experiment observations. In the Bayesian approach, several model specifications were compared based on model fit, the usability of the final value set and how they reflect the elicitation procedure (e.g. censoring). A hybrid approach (using composite time trade-off and discrete choice experiment data) was employed in the final set, which was compared with the existing ones: EQ-5D-3L and EQ-5D-5L cross-walk.

RESULTS

Data from 1252 respondents (11,480 composite time trade-off valuations and 8764 discrete choice experiment pairs) were collected over the period June to October 2016. The final model accounted for random parameters, error scaling with fat tails, censoring at - 1, unwillingness to trade in time trade-off by the religious people and Cauchy distribution in discrete choice experiments. Pain/discomfort impacts the utility most: the disutility equals 0.575 when at level 5. In the value set, 4.4% of EQ-5D-5L states are worse than dead. The new value set has a comparable range (minimum of - 0.590 compared to - 0.523) and the same ordering of the first three dimensions (pain/discomfort, mobility, self-care) as the EQ-5D-3L value set and the EQ-5D-5L cross-walk value set. Moreover, it is more sensitive to a moderate decline in health.

CONCLUSIONS

The new value set supports consistency with past decisions in cost-utility studies, while offering a better assessment of even moderate improvements in health. It could represent an option for Central and Eastern Europe countries lacking their own value sets.

Measuring health-related quality of life in the general population and Roma communities in Romania: study protocol for two cross-sectional studies

INTRODUCTION

The importance of health-related quality of life (HRQoL) is increasing and many healthcare authorities recommend the use of measures that account for both mortality and morbidity. This study will determine, for the first time in Romania, value sets for EuroQoL-five-dimensions-3-level (EQ-5D-3L) and EQ-5D-5L questionnaires and their population norms (study 1). It will also compare the HRQoL (measured with EQ-5D-5L) of Roma communities in Romania with that of the general population (study 2).

METHODS AND ANALYSIS

Cross-sectional studies of face-to-face interviews conducted in representative samples of the Romanian general population and Romanian Roma communities. 1614 non-institutionalised adults older than 18 years will be interviewed using a computer-assisted interview for study 1. Participants will complete EQ-5D-3L and 5L, 13 composite time trade-off tasks (cTTO), 7 discrete choice experiment questions (DCE) and sociodemographic questions. For study 2, 606 non-institutionalised self-identified Roma people older than 18 years will be interviewed using a pencil-and-paper interview. Participants will complete EQ-5D-5L and the same sociodemographic questions as for study 1. The 3L value set will be estimated using econometric models and the cTTO data. cTTO and DCE data will be used for the 5L value set. Population norms will be reported by age and gender. The ORs for reporting different levels of problems and the most common health states in the population will be estimated. For study 2, t-tests and analysis of variance will be used to explore differences between groups in HRQoL and for each EQ-5D.

ETHICS AND DISSEMINATION

Ethics approval was given by the National Bioethics Committee of Medicines and Medical Devices Romania and Newcastle University's Research Ethics Committee. Results will be published in peer-reviewed journals, presented at scientific conferences and on the project's website. The EQ-5D-5L anonymised datasets will be deposited in a centralised repository. Two public workshops with local authorities, physicians and patients' associations will be held.

United States Valuation of EQ-5D-5L Health States Using an International Protocol

OBJECTIVE

To derive a US-based value set for the EQ-5D-5L questionnaire using an international, standardized protocol developed by the EuroQol Group.

METHODS

Respondents from the US adult population were quota-sampled on the basis of age, sex, ethnicity, and race. Trained interviewers guided participants in completing composite time trade-off (cTTO) and discrete choice experiment (DCE) tasks using the EuroQol Valuation Technology software and routine quality control measures. Data were modeled using a Tobit model for cTTO data, a mixed logit model for DCE data, and a hybrid model that combined cTTO and DCE data. Model performance was compared on the basis of logical ordering of coefficients, statistical significance, parsimony, and theoretical considerations.

RESULTS

Of 1134 respondents, 1062, 1099, and 1102 respondents provided useable cTTO, DCE, and cTTO or DCE responses, respectively, on the basis of quality control criteria and interviewer judgment. Respondent demographic characteristics and health status were similar to the 2015 US Census. The Tobit model was selected as the preferred model to generate the value set. Values ranged from -0.573 (55 555) to 1 (11 111), with 20% of all predicted health states scores less than 0 (ie, worse than dead).

CONCLUSIONS

A societal value set for the EQ-5D-5L was developed that can be used for economic evaluations and decision making in US health systems. The internationally established, standardized protocol used to develop this US-based value set was recommended by the EuroQol Group and can facilitate cross-country comparisons.

A hybrid modelling approach for eliciting health state preferences: the Portuguese EQ-5D-5L value set

BACKGROUND

The EQ-5D is a generic preference-based quality of life measure considered useful for supporting clinical and policy decisions by providing utility values that can easily be converted into quality-adjusted life years to be integrated in cost-utility economic evaluations. Although the three-level classification system of the EuroQol questionnaire (EQ-5D-3L) is still the most popular preference-based instrument used worldwide, several studies reported a ceiling effect on this version, especially in healthy and/or young individuals. In 2009, the EuroQol Group introduced a five-level EQ-5D, which expands the descriptive system from three to five levels within the same five dimensions. For this version to be used in health economic evaluation, societal values need to be assigned to the 3125 health states generated by this instrument.

OBJECTIVES

The aims of this study were to elicit the EQ-5D-5L health state preferences from the general Portuguese population and to derive the Portuguese value set for the EQ-5D-5L.

METHODS

A representative sample of the Portuguese general population aged above 18 years was stratified by age and gender (n = 1451). Between October 2015 and July 2016, 28 interviewers carried out a series of 1-h-long computer-assisted personal interviews following the EuroQol Valuation Technology protocol. Each interview included the valuation of ten health states using the composite time trade-off (cTTO) and seven pairs of discrete choice experiments (DCEs). A standardized tool for quality control was used to assess the quality of the data as well as direct supervision and cross-examination of 10% of the global sample size. Data from both cTTO and DCE valuation tasks were modelled using a censored heteroskedastic hybrid model.

RESULTS

Interviewers complied with the quality control protocol in providing high-quality valuation data. The hybrid econometric model had consistent and significant parameters. The derived societal values for the Portuguese population ranged from - 0.603 to 1.

CONCLUSION

This study provided the Portuguese value set for the EQ-5D-5L on the basis of a hybrid econometric model using cTTO and DCE data. These results represent the preferences of the Portuguese population and are recommended to inform health decision-making in Portugal.

Exploring the Impact of Adding a Respiratory Dimension to the EQ-5D-5L

Objectives. To evaluate the impact of adding a respiratory dimension (a bolt-on dimension) to the EQ-5D-5L health state valuations. Methods. Based on extensive regression and principal component analyses, 2 respiratory bolt-on candidates were formulated: R1, limitations in physical activities due to shortness of breath, and R2, breathing problems. Valuation interviews for the selected bolt-ons were performed with a representative sample from the Dutch general public using the standardized interview protocol and software of the EuroQol group. Hybrid models based on the combined time-tradeoff (TTO) and discrete choice experiment (DCE) data were estimated to assess whether the 5 levels of the respiratory bolt-on led to significant changes in utility values. Results. For each bolt-on candidate, slightly more than 200 valuation interviews were conducted. Mean TTO values and DCE choice probabilities for health states with a level 4 or 5 for the respiratory dimension were significantly lower compared with the same health states in the Dutch EQ-5D-5L valuation study without the respiratory dimension. Results of hybrid models showed that for the bolt-on “limitations in physical activities,” the utility decrements were significant for level 3 (–0.055), level 4 (–0.087), and level 5 (–0.135). For “breathing problems,” the utility decrements for the same levels were greater (–0.086, –0.219, and –0.327, respectively). Conclusions. The addition of each of the 2 respiratory bolt-ons to the EQ-5D-5L had a significant effect on the valuation of health states with severe levels for the bolt-on. The bolt-on dimension “breathing problems” showed the greatest utility decrements and therefore seems the most appropriate respiratory bolt-on dimension.

EQ-5D-5L Valuation for the Malaysian Population

OBJECTIVES

The aim of this study was to develop an EQ-5D-5L value set reflecting the health preferences of the Malaysian adult population.

METHODS

Respondents were sampled with quotas for urbanicity, gender, age, and ethnicity to ensure representativeness of the Malaysian population. The study was conducted using a standardized protocol involving the EuroQol Valuation Technology (EQ-VT) computer-assisted interview system. Respondents were administered ten composite time trade-off (C-TTO) tasks and seven discrete choice experiment (DCE) tasks. Both linear main effects and constrained non-linear regression models of C-TTO-only data and hybrid models combining C-TTO and DCE data were explored to determine an efficient and informative model for value set prediction.

RESULTS

Data from 1125 respondents representative of the Malaysian population were included in the analysis. Logical consistency was present in all models tested. Using cross-validation, eight-parameter models for C-TTO only and C-TTO + DCE hybrid data displayed greater out-of-sample predictive accuracy than their 20-parameter, main-effect counterparts. The hybrid eight-parameter model was chosen to represent the Malaysian value set, as it displayed greater out-of-sample predictive accuracy over C-TTO data than the C-TTO-only model, and produced more precise estimates. The estimated value set ranged from - 0.442 to 1.

CONCLUSIONS

The constrained eight-parameter hybrid model demonstrated the best potential in representing the Malaysian value set. The presence of the Malaysian EQ-5D-5L value set will facilitate its application in research and health technology assessment activities.

A new method for valuing health: directly eliciting personal utility functions

BACKGROUND

Standard methods for eliciting the preference data upon which 'value sets' are based generally have in common an aim to 'uncover' people's preferences by asking them to evaluate a subset of health states, then using their responses to infer their preferences over all dimensions and levels. An alternative approach is to ask people directly about the relative importance to them of the dimensions, levels and interactions between them. This paper describes a new stated preference approach for directly eliciting personal utility functions (PUFs), and reports a pilot study to test its feasibility for valuing the EQ-5D.

METHODS

A questionnaire was developed, designed to directly elicit PUFs from general public respondents via computer-assisted personal interviews, with a focus on helping respondents to reflect and deliberate on their preferences. The questionnaire was piloted in England.

RESULTS

Seventy-six interviews were conducted in December 2015. Overall, pain/discomfort and mobility were found to be the most important of the EQ-5D dimensions. The ratings for intermediate improvements in each dimension show heterogeneity, both within and between respondents. Almost a quarter of respondents indicated that no EQ-5D health states are worse than dead.

DISCUSSION

The PUF approach appears to be feasible, and has the potential to yield meaningful, well-informed preference data from respondents that can be aggregated to yield a value set for the EQ-5D. A deliberative approach to health state valuation also has the potential to complement and develop existing valuation methods. Further refinement of some elements of the approach is required.

Choice Defines QALYs: A US Valuation of the EQ-5D-5L

BACKGROUND

The 5-level version of the EQ-5D (EQ-5D-5L) was introduced as an improvement on the original 3-level version (EQ-5D-3L). To date, 6 country-specific value sets have been published for EQ-5D-5L and 9 US value sets have been published for other instruments. Our aims were to (1) produce EQ-5D-5L values on a quality-adjusted life year (QALY) scale from the perspective of US adults and (2) compare them with US EQ-5D-3L values and the other country-specific EQ-5D-5L values.

METHODS

In 2016, 8222 US respondents from all 50 states and Washington, DC completed an online survey including a discrete choice experiment with 20 paired comparisons. Each comparison asked respondents, "Which do you prefer?" regarding a pair of alternatives described using EQ-5D-5L and lifespan attributes. On the basis of more than 50 choices on each of the 3160 pairs, we estimated EQ-5D-5L values on a QALY scale and compared them with the US EQ-5D-3L values and the other country-specific EQ-5D-5L values.

RESULTS

Ranging from -0.287 (55555) to 0.992 (11121) on a QALY scale, the estimated EQ-5D-5L values were similar to the US EQ-5D-3L values. Compared with the US EQ-5D-3L values, the values exhibited greater sensitivity and specificity and higher correlation with the EQ-5D-5L values of other countries, particularly England.

CONCLUSIONS

Like previous US valuation studies, this study produced nationally representative EQ-5D-5L values on a QALY scale. The results further demonstrate the advantages of the EQ-5D-5L over its 3-level predecessor as a preference-based summary measure of health-related quality of life from the perspective of US adults.

Health State Utilities for Acute Myeloid Leukaemia: A Time Trade-off Study

OBJECTIVES

Acute myeloid leukaemia (AML) is an aggressive haematological cancer associated with significant humanistic impact. The current study assessed how the general public in the United Kingdom (UK) values AML health states.

METHODS

The composite time trade-off (cTTO) methodology was employed to elicit health state utilities in AML. Pertinent AML literature related to symptom and quality-of-life impact including physical, functional and emotional well-being, as well as the safety profile of AML treatments, were taken into consideration for drafting health state descriptions. Ten health states included in the study were newly diagnosed AML, induction, consolidation, maintenance, long-term follow-up, relapsed/refractory, stem-cell transplant (SCT) procedure, SCT recovery, SCT long-term follow-up with complications and SCT long-term follow-up without complications. The descriptions were validated by haematologists and nurse specialists for clinical accuracy and completeness. A total of 210 individuals from the general UK population participated in the cTTO interviews. Descriptive statistics were computed for health state utility values.

RESULTS

The mean age of the participants was 44.0 years (standard deviation [SD] 14.9, range 18-81) and comprised 129 (61.4%) female participants. The utility values ranged from 0.94 (SD 0.13) for SCT long-term follow-up without complications to - 0.21 (SD 0.62) for the SCT procedure.

CONCLUSIONS

The study provides health utilities for a range of AML health states, with the SCT procedure health state being valued worse than death. The utilities obtained in this study can be employed as inputs in cost-effectiveness analyses of AML therapies.

Overview, Update, and Lessons Learned From the International EQ-5D-5L Valuation Work: Version 2 of the EQ-5D-5L Valuation Protocol

A standardized 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) valuation protocol was first used in national studies in the period 2012 to 2013. A set of problems encountered in this initial wave of valuation studies led to the subsequent refinement of the valuation protocol. To clarify lessons learned and how the protocol was updated when moving from version 1.0 to the current version 2.1 and 2.0, this article will (1) present the challenges faced in EQ-5D-5L valuation since 2012 and how these were resolved and (2) describe in depth a set of new challenges that have become central in currently ongoing research on how EQ-5D-5L health states should be valued and modeled.

Valuation of the EQ-5D-5L in Taiwan

OBJECTIVES

To date, a value set for the EQ-5D-5L based on the health state preferences of the general Taiwanese population has not been available. This study aimed to develop a Taiwanese value set for EQ-5D-5L to facilitate health technology assessment for medical products and services.

METHODS

An international standardized protocol for EQ-5D-5L valuation studies developed by the EuroQol group was adopted. Adult members of the general public were recruited from six geographic regions in Taiwan. In computer-based face-to-face interviews, each participant completed 10 composite time trade-off (C-TTO) tasks and 7 discrete choice experiment (DCE) tasks. The C-TTO and DCE data were modeled alone or in combination (using hybrid models) with additive models containing 20 dummy variables as main effects. The model performance was assessed both quantitatively and qualitatively (mainly logical consistency and prediction patterns).

RESULTS

Of 1,073 recruited participants, 1,000 completed the study. Approximately 13% of observed utility values were -1 in the C-TTO tasks. The hybrid model, using all available data that assumed C-TTO response values left-censored at -1 and with main effects coefficients with logical consistency (monotonicity), was considered as the most appropriate model. The predicted utility ranged from -1.0259 to 1.

CONCLUSIONS

An EQ-5D-5L value set was developed for Taiwan using an established study protocol and a representative sample of the general population. This may facilitate health economic evaluations and decision making on resource allocation under Taiwan's national health insurance program in the future.

Valuation of EQ-5D-5L health states: a comparison of seven Asian populations

Objectives: To compare the time trade-off (TTO) utility values of EQ-5D-5L health states elicited from different general populations in Asia. Methods: We analyzed the TTO data from seven Asian EQ-5D-5L valuation studies in which utility values of 86 EQ-5D-5L health states were elicited from general population samples. An eight-parameter multiplicative regression model including five dimension parameters (mobility [MO], self-care, usual activities [UA], pain/discomfort, anxiety/depression) and three level parameters (level 2 [L2], level 3 [L3], and level 4 [L4]) was used to model the data from each of the populations. The model coefficients were compared to understand how the valuations of EQ-5D-5L health states differ. Results: For dimension parameters, Korea and Indonesia generally had the highest and lowest values among the populations, respectively; UA and MO commonly had the highest and lowest values among the parameters, respectively. For level parameters, Singapore and Korea generally had the highest and lowest values, respectively; L2 showed less variance compared to L3 and L4. Koreans, Indonesians, and Singaporeans appeared to have different health preferences compared with other populations. Conclusion: Utility values of EQ-5D-5L health states differ among Asian populations, suggesting that each health system should establish and use its own value set.

Valuation of EuroQol Five-Dimensional Questionnaire, Youth Version (EQ-5D-Y) and EuroQol Five-Dimensional Questionnaire, Three-Level Version (EQ-5D-3L) Health States: The Impact of Wording and Perspective

BACKGROUND

Valuations of health states were affected by the wording of the two instruments (EQ-5D-3L and EQ-5D-Y) and by the perspective taken (child or adult).

OBJECTIVES

There is a growing demand for value sets for the EQ-5D-Y (EQ-5D instrument for younger populations). Given the similarities between EQ-5D-Y and EQ-5D-3L, we investigated whether valuations of health states were affected by the differences in wording between the two instruments and by the perspective taken in the valuation exercise (child or adult).

STUDY DESIGN

Respondents were randomly assigned to EQ-5D-3L or EQ-5D-Y (instrument) and further into two groups that either valued health states for an adult or for a 10-year-old child (perspective). The valuation tasks were composite time trade-off (C-TTO) and discrete choice experiments (DCE), including comparisons with death (DCE + death). Members of the adult general population in four countries (Germany, Netherlands, Spain, England) participated in computer-assisted personal interviews.

METHODS

Two-way multivariate analysis of variance (MANOVA) and post hoc tests were used to compare C-TTO responses and chi-square tests were conducted to compare DCE + death valuations.

RESULTS

A significant interaction effect between instrument and perspective for C-TTO responses was found. Significant differences by perspective (adult and child) occurred only for the EQ-5D-3L. Significant differences in values between instruments (EQ-5D-3L and EQ-5D-Y) occurred only for the adult perspective. Both significant results were confirmed by the DCE + death results. When comparing EQ-5D-3L for adult perspective and EQ-5D-Y for child perspective, values were also significantly different.

CONCLUSIONS

The results identified an interaction effect between wording of the instrument and perspective on elicited values, suggesting that current EQ-5D-3L value sets should not be employed to assign values to EQ-5D-Y health states.

The EQ-5D-5L Valuation study in Thailand

BACKGROUND

At present, health technology assessment (HTA) guidelines of many countries including Thailand have recommended EQ-5D as the preferred method for assessing utility. This study aims to generate an EQ-5D-5L value set based on societal preferences of Thai population.

METHODS

A 1,207 representative sample was recruited using a stratified multi-stage quota sampling technique. Face-to-face, computer-assisted interviews using the EuroQol Valuation Technology (EQ-VT) software were employed. To elicit preference score, each respondent was asked to value health states using composite time trade-off (cTTO), and discrete choice experiment (DCE). All data were integrated and analyzed using a hybrid regression model to estimate the value set.

RESULTS

Characteristics of 1,207 participants were generally similar to those of Thai general population. The coefficients generated from a hybrid model were logically consistent. The second best value is 0.9436 for health state 11121 and the worst state (55555) value is -0.4212. Mobility shows the greatest impact to utility decrement.

CONCLUSIONS

Our study developed a Thai value set for EQ-5D using hybrid model. The findings from this study are of important to facilitate health technology assessment studies to inform policy decision-making as well as to promote the use of EQ-5D-5L in various health research in Thailand.

Evaluation of Split Version and Feedback Module on the Improvement of Time Trade-Off Data

BACKGROUND

EQ-5D-5L valuation studies previously reported many inconsistent responses in time trade-off (TTO) data. A number of possible elements, including ordering effects of the valuation tasks, mistakes at the sorting question, and interviewers' (learning) effects, may contribute to their inconsistency.

OBJECTIVES

This study aimed to evaluate the effect of two modifications on consistency of TTO data in The Netherlands (NL) and Hong Kong (HK): (1) separating the valuation of the Better than Dead (BTD) and Worse than Dead (WTD) states; and (2) Implementation of feedback (FB) module by offering an opportunity to review TTO responses.

METHODS

A crossover design with two study arms was used to test the effect of the modifications. In each jurisdiction, six interviewers were involved where half the interviewers started using the standard version, and the other half started with the split version. Each version was switched after every 25 (NL) or 30 (HK) interviews until 400 interviews were completed.

RESULTS

In the NL and HK, 404 and 403 respondents participated, respectively. With the use of the FB module, the proportion of respondents with inconsistent responses was lowered from 17.8% to 10.6% (P < 0.001) in NL and from 31.8% to 22.3% (P = 0.003) in HK. The result of separating the valuation of BTD and WTD states was not straightforward because it reduced the inconsistency rate in NL but not in HK.

CONCLUSIONS

The results support implementation of the FB module to promote the consistency of the data. The separation of the BTD and WTD task is not supported.

Is EQ-5D-5L Better Than EQ-5D-3L? A Head-to-Head Comparison of Descriptive Systems and Value Sets from Seven Countries

OBJECTIVE

This study describes the first empirical head-to-head comparison of EQ-5D-3L (3L) and EQ-5D-5L (5L) value sets for multiple countries.

METHODS

A large multinational dataset, including 3L and 5L data for eight patient groups and a student cohort, was used to compare 3L versus 5L value sets for Canada, China, England/UK (5L/3L, respectively), Japan, The Netherlands, South Korea and Spain. We used distributional analyses and two methods exploring discriminatory power: relative efficiency as assessed by the F statistic, and an area under the curve for the receiver-operating characteristics approach. Differences in outcomes were explored by separating descriptive system effects from valuation effects, and by exploring distributional location effects.

RESULTS

In terms of distributional evenness, efficiency of scale use and the face validity of the resulting distributions, 5L was superior, leading to an increase in sensitivity and precision in health status measurement. When compared with 5L, 3L systematically overestimated health problems and consequently underestimated utilities. This led to bias, i.e. over- or underestimations of discriminatory power.

CONCLUSION

We conclude that 5L provides more precise measurement at individual and group levels, both in terms of descriptive system data and utilities. The increased sensitivity and precision of 5L is likely to be generalisable to longitudinal studies, such as in intervention designs. Hence, we recommend the use of the 5L across applications, including economic evaluation, clinical and public health studies. The evaluative framework proved to be useful in assessing preference-based instruments and might be useful for future work in the development of descriptive systems or health classifications.

German Value Set for the EQ-5D-5L

OBJECTIVES

The objective of this study was to develop a value set for EQ-5D-5L based on the societal preferences of the German population. As the first country to do so, the study design used the improved EQ-5D-5L valuation protocol 2.0 developed by the EuroQol Group, including a feedback module as internal validation and a quality control process that was missing in the first wave of EQ-5D-5L valuation studies.

METHODS

A representative sample of the general German population (n = 1158) was interviewed using a composite time trade-off and a discrete choice experiment under close quality control. Econometric modeling was used to estimate values for all 3125 possible health states described by EQ-5D-5L. The value set was based on a hybrid model including all available information from the composite time trade-off and discrete choice experiment valuations without any exclusions due to data issues.

RESULTS

The final German value set was constructed from a combination of a conditional logit model for the discrete choice experiment data and a censored at -1 Tobit model for the composite time trade-off data, correcting for heteroskedasticity. The value set had logically consistent parameter estimates (p < 0.001 for all coefficients). The predicted EQ-5D-5L index values ranged from -0.661 to 1.

CONCLUSIONS

This study provided values for the health states of the German version of EQ-5D-5L representing the preferences of the German population. The study successfully employed for the first time worldwide the improved protocol 2.0. The value set enables the use of the EQ-5D-5L instrument in economic evaluations and in clinical studies.

Handling Data Quality Issues to Estimate the Spanish EQ-5D-5L Value Set Using a Hybrid Interval Regression Approach

BACKGROUND

The Spanish five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) valuation study was the first to use the EuroQol Valuation Technology protocol, including composite time trade-off (C-TTO) and discrete choice experiments (DCE). In this study, its investigators noticed that some interviewers did not fully explain the C-TTO task to respondents. Evidence from a follow-up study in 2014 confirmed that when interviewers followed the protocol, the distribution of C-TTO responses widened.

OBJECTIVES

To handle the data quality issues in the C-TTO responses by estimating a hybrid interval regression model to produce a Spanish EQ-5D-5L value set.

METHODS

Four different models were tested. Model 0 integrated C-TTO and DCE responses in a hybrid model and models 1 to 3 altered the interpretation of the C-TTO responses: model 1 allowed for censoring of the C-TTO responses, whereas model 2 incorporated interval responses and model 3 included the interviewer-specific protocol violations. For external validation, the predictions of the four models were compared with those of the follow-up study using the Lin's concordance correlation coefficient.

RESULTS

This stepwise approach to modeling C-TTO and DCE responses improved the concordance between the valuation and follow-up studies (concordance correlation coefficient: 0.948 [model 0], 0.958 [model 1], 0.952 [model 2], and 0.989 [model 3]). We recommend the estimates from model 3, because its hybrid interval regression model addresses the data quality issues found in the valuation study.

CONCLUSIONS

Protocol violations may occur in any valuation study; handling them in the analysis can improve external validity. The resulting EQ-5D-5L value set (model 3) can be applied to inform Spanish health technology assessments.

Assessing the Use of a Feedback Module to Model EQ-5D-5L Health States Values in Hong Kong

BACKGROUND

An international valuation protocol exists for obtaining societal values for each of the 3125 health states of the five-level EuroQol-five dimensions (EQ-5D-5L) questionnaire. A feedback module (FM) that can be related to theoretical models used in behavioral economics was recently included in this protocol.

OBJECTIVES

Our objective was to assess the impact of using an FM to estimate an EQ-5D-5L value set in Hong Kong.

METHODS

EQ-5D-5L health states were elicited using a composite time trade-off (C-TTO) and a discrete-choice (DC) experiment. Use of the FM according to participant characteristics and the impact of the FM on the number of inconsistent C-TTO responses were assessed. We employed a main-effects hybrid model that combined data from both elicitation techniques.

RESULTS

In total, 1014 individuals completed the survey. The sample was representative of the general Chinese Hong Kong population in terms of sex, educational attainment, marital status, and most age groups but not for employment status. The use of the FM reduced the number of C-TTO inconsistencies. Participant characteristics differed significantly between those who used and did not use the FM. The model without a constant resulted in logical consistent coefficients and was therefore selected as the model to produce the value set. The predicted EQ-5D-5L values ranged from -0.864 to 1.

CONCLUSIONS

The use of an FM to allow participants to exclude C-TTO responses reduced the number of inconsistent responses and improved the quality of the data when estimating an EQ-5D-5L value set in Hong Kong.

The Indonesian EQ-5D-5L Value Set

BACKGROUND

The EQ-5D is one of the most used generic health-related quality-of-life (HRQOL) instruments worldwide. To make the EQ-5D suitable for use in economic evaluations, a societal-based value set is needed. Indonesia does not have such a value set.

OBJECTIVE

The aim of this study was to derive an EQ-5D-5L value set from the Indonesian general population.

METHODS

A representative sample aged 17 years and over was recruited from the Indonesian general population. A multi-stage stratified quota method with respect to residence, gender, age, level of education, religion and ethnicity was utilized. Two elicitation techniques, the composite time trade-off (C-TTO) and discrete choice experiments (DCE) were applied. Interviews were undertaken by trained interviewers using computer-assisted face-to-face interviews with the EuroQol Valuation Technology (EQ-VT) platform. To estimate the value set, a hybrid regression model combining C-TTO and DCE data was used.

RESULTS

A total of 1054 respondents who completed the interview formed the sample for the analysis. Their characteristics were similar to those of the Indonesian population. Most self-reported health problems were observed in the pain/discomfort dimension (39.66%) and least in the self-care dimension (1.89%). In the value set, the maximum value was 1.000 for full health (health state '11111') followed by the health state '11112' with value 0.921. The minimum value was -0.865 for the worst state ('55555'). Preference values were most affected by mobility and least by pain/discomfort.

CONCLUSIONS

We now have a representative EQ-5D-5L value set for Indonesia. We expect our results will promote and facilitate health economic evaluations and HRQOL research in Indonesia.

Logical inconsistencies in time trade-off valuation of EQ-5D-5L health states: Whose fault is it?

INTRODUCTION

Inconsistency in the time trade-off (TTO) task in EQ-5D-5L occurs when a respondent gives a higher value to a logically worse health state, the occurrence of inconsistency compromises the quality of the data. It is not yet clear which factors are associated with individual level inconsistency. Relating inconsistency to the characteristics of the respondent, interviewer, and the interview process could be helpful in understanding the causes of inconsistency. The objective of this paper is to discover the factors associated with individual level inconsistencies.

METHODS

Twenty interviewers interviewed 1,296 respondents and each respondent valued 10 health states using the EQ-VT platform in 5 cities in China. At the respondent level, inconsistency was identified in terms of severity and quantity and related to the respondent's background characteristics, the time and iterations spent on the wheelchair example task, and the formal TTO tasks, using multilevel multinomial regression analyses. Interviewers' impact on inconsistencies was analyzed using single level multinomial regression analyses.

RESULTS

In the full dataset, slight inconsistency was more related to the interview process (Time spent on TTO task: RRR = 1.246 with 95%CI: 1.076,1.441; time spent on Wheelchair example: RRR = 0.815 with 95%CI:0.699,0.952) while severe inconsistency was more related to respondent's gender (Gender: RRR = 2.347 with 95%CI:1.429,3.855). One Interviewer (Interviewer 7: RRR = 7.335 with 95%CI:1.908,28.195) and interviewer's experience (Sequence: RRR = 0.511 with 95%CI:0.385,0.678) in general showed strong influence over inconsistency in the TTO task.

CONCLUSION

In conclusion, logical inconsistency in the valuation of EQ-5D-5L health states is associated not only with respondents' characteristics but also with interviewers' performance and the interview process. The role of interviewers and the importance of interviewer training may be more crucial than hitherto believed. This finding could be generalizable to other interviewer-administered health-state valuation study.

Valuation of the EQ-5D-5L with composite time trade-off for the German population - an exploratory study

BACKGROUND

The EuroQol Group has extended the severity levels of the EQ-5D from three to five (EQ-5D-5L). There are valuation studies worldwide planned in order to convert the EQ-5D-5L health states into a single preference-based summary score based on country-specific value sets of social health status preference valuations. The EuroQol Group developed an internationally standardised EQ-5D-5L valuation protocol. Based on the experiences of the first wave of valuation studies applying the protocol, a number of modifications to the implementation of composite time trade-off (cTTO) were proposed and tested in an exploratory study in Germany.

METHODS

The aim of the study is to test the improved EQ-5D-5L valuation protocol 1.1 and the implementation of three modifications: (1) introduction of ranking task, (2) separating time trade-off (TTO) tasks for health states "Better Than Dead"(BTD)/"Worse Than Dead" (WTD), (3) allow for removal of problematic valuations from the cTTO data (the feedback module). Data were collected in computer assisted personal interviews with 200 members of the German general public.

RESULTS

In comparison to the first wave of valuation studies a higher data quality can be observed in both study arms: increasing number of WTD valuations, reduced inconsistencies for health state 55555 as well as higher values for mild health states. Comparing both study arms, mean observed cTTO value for severity 6 is higher in the test arm. The proportion of inconsistent cTTO responses is lower in the test arm than in the control arm and is further reduced by the feedback module. The ranking task prolongs the interview without the desired effect.

CONCLUSIONS

Both study arms yielded higher data quality in comparison to the first wave of EQ-5D-5L valuation studies. The valuation protocol combined with an intensive interviewer training and close data monitoring showed a high feasibility and acceptability to the respondents of the general population as well as the interviewers in Germany. Based on the results of this study and other countries, the separation of TTO tasks for health states BTD/WTD and the feedback module will be implemented in the valuation study for the EQ-5D-5L for Germany.