Evaluation of EuroQol Valuation Technology (EQ-VT) Designs to Generate National Value Sets: Learnings from the Development of an EQ-5D Value Set for India Using an Extended Design (DEVINE) Study.

INTRODUCTION: Countries develop their EQ-5D-5L value sets using the EuroQol Valuation Technology (EQ-VT) protocol. This study aims to assess if extension in the conventional EQ-VT design can lead to development of value sets with improved precision. METHODS: A cross-sectional survey was undertaken in a representative sample of 3,548 adult respondents, selected from 5 different states of India using a multistage stratified random sampling technique. A novel extended EQ-VT design was created that included 18 blocks of 10 health states, comprising 150 unique health states and 135 observations per health state. In addition to the standard EQ-VT design, which is based on 86 health states and 100 observations per health state, 3 extended designs were assessed for their predictive performance. The extended designs were created by 1) increasing the number of observations per health state in the design, 2) increasing the number of health states in the design, and 3) implementing both 1) and 2) at the same time. Subsamples of the data set were created for separate designs. The root mean squared error (RMSE) and mean absolute error (MAE) were used to measure the predictive accuracy of the conventional and extended designs. RESULTS: The average RMSE and MAE for the standard EQ-VT design were 0.055 and 0.041, respectively, for the 150 health states. All 3 types of design extensions showed lower RMSE and MAE values as compared with the standard design and hence yielded better predictive performance. RMSE and MAE were lowest (0.051 and 0.039, respectively) for the designs that use a greater number of health states. Extending the design with inclusion of more health states was shown to improve the predictive performance even when the sample size was fixed at 1,000. CONCLUSION: Although the standard EQ-VT design performs well, its prediction accuracy can be further improved by extending its design. The addition of more health states in EQ-VT is more beneficial than increasing the number of observations per health state. HIGHLIGHTS: The EQ-5D-5L value sets are developed using the standardized EuroQol Valuation Technology (EQ-VT) protocol. This is the first study to empirically assess how much can be gained from extending the standard EQ-VT design in terms of sample size and/or health states. It not only presents useful insights into the performance of the standard design of the EQ-VT but also tests the potential extensions in the standard EQ-VT design in terms of increasing the health states to be directly valued as well as the number of observations recorded to predict the utility value of each of these health states.The study demonstrates that the standard EQ-VT design performs good, and an extension in the design of the standard EQ-VT can lead to further improvement in its performance. The addition of more health states in EQ-VT is more beneficial than increasing the number of observations per health state. Extending the design with inclusion of more health states marginally improves the predictive performance even when the sample size was fixed at 1,000.The findings of the study will streamline the systematic process for generating precise EQ-5D-5L value sets, thus facilitating the conduct of credible, transparent, and robust outcome valuation in health technology assessments.

Using Age-Specific Values for Pediatric HRQoL in Cost-Effectiveness Analysis: Is There a Problem to Be Solved? If So, How?

Value sets for the EQ-5D-Y-3L published to date appear to have distinctive characteristics compared with value sets for corresponding adult instruments: in many cases, the value for the worst health state is higher and there are fewer values < 0. The aim of this paper is to consider how and why values for child and adult health differ; and what the implications of that are for the use of EQ-5D-Y-3L values in economic evaluations to inform healthcare resource allocation decisions. We posit four potential explanations for the differences in values: (a) The wording of severity labels may mean the worst problems on the EQ-5D-Y-3L are descriptively less severe than those on the EQ-5D-5L; (b) Adults may genuinely consider that children are less badly affected than adults by descriptively similar health issues. That is, for any given health problem, adult respondents in valuation studies consider children's overall health-related quality of life (HRQoL) on average to be higher than that for adults; (c) Values are being sought by eliciting adults' stated preferences for HRQoL in another person, rather than in themselves (regardless of whether the 'other person' concerned is a child); and (d) The need to elicit preferences for child HRQoL that are anchored at dead = 0 invokes special considerations regarding children's survival. Existing evidence does not rule out the possibility that (c) and (d) exert an upward bias in values. We consider the implications of that for the interpretation and use of values for pediatric HRQoL. Alternative methods for valuing children's HRQoL in a manner that is not 'age specific' are possible and may help to avoid issues of non-comparability. Use of these methods would place the onus on health technology assessment bodies to reflect any special considerations regarding child quality-adjusted life-year gains.

Indonesia youth population norms for EQ-5D-Y-3 L, EQ-5D-Y-5 L and the PedsQL generic core scale: lower health related quality of life relates to high economic status and stress.

BACKGROUND: The availability of population norms from generic health-related quality of life (HRQoL) instruments can support the interpretation of health outcomes. This study aimed to provide Indonesian youth population norms for the generic HRQoL measures: EQ-5D-Y-3 L, EQ-5D-Y-5 L, and the PedsQL Generic Core Scales. In addition the opportunity arising from the generation of a large representative sample was taken to explore the relationships between HRQoL, health, and socio-economic factors. METHODS: A representative sample of 1103 Indonesian children (aged 8-16 years) completed EQ-5D-Y-3 L, EQ-5D-Y-5 L, the PedsQL Generic Core Scales, and questions related to demographic data and self-reported health status. A stratified quota sampling design was used to represent Indonesian children in terms of residence, age, gender, and geographical area. Family expenses per capita per month were retrieved from parents to determine a child's economic status. RESULTS: The total sample was representative of the Indonesian youth general population. The proportions of participants who reported problems were 43.35% (EQ-5D-Y-3 L), 44.10% (EQ-5D-Y-5 L), and 94.93% (PedsQL Generic), with 31.7% of children reporting health complaints. Older children (13-16 years) reported more problems than younger children (8-12 years). Children living in urban areas reported more problems than children living in rural areas. The lowest value health state reported was '12332' (valued at 0.54), and the minimum EQ VAS score was 60.00. Moderate correlations were found between EQ-5D-Y-3 L values to EQ VAS scores and to PedsQL Total Score. Hierarchical regression analysis showed that females, older age, and having health complaints contributed to a lower level of HRQoL as measured by EQ-5D-Y-3 L values, EQ VAS, and PedsQL Total Score. Remarkably, children with high economic status had lower EQ VAS and PedsQL Total Scores. Among symptoms, 'having stress' had the largest influence with respect to lower EQ-5D-Y-3L values, EQ VAS, and PedsQL Total Score. CONCLUSIONS: Population norms for children's HRQoL as measured by EQ-5D-Y-3 L, EQ-5D-Y-5 L, and the PedsQL Generic Scales are now available for Indonesia. Age, gender, economic status, and health complaints were related to children's HRQoL. These results provide a basis for health studies and health policy for the youth population of Indonesia.

Development of an EQ-5D Value Set for India Using an Extended Design (DEVINE) Study: The Indian 5-Level Version EQ-5D Value Set.

OBJECTIVES: This study aimed to develop the Indian 5-level version EQ-5D (EQ-5D-5L) value set, which is a key input in health technology assessment for resource allocation in healthcare. METHODS: A cross-sectional survey using the EuroQol Group's Valuation Technology was undertaken in a representative sample of 3548 adult respondents, selected from 5 different states of India using a multistage stratified random sampling technique. The participants were interviewed using a computer-assisted personal interviewing technique. This study adopted a novel extended EuroQol Group's Valuation Technology design that included 18 blocks of 10 composite time trade-off (c-TTO) tasks, comprising 150 unique health states, and 36 blocks of 7 discrete choice experiment (DCE) tasks, comprising 252 DCE pairs. Different models were explored for their predictive performance. Hybrid modeling approach using both c-TTO and DCE data was used to estimate the value set. RESULTS: A total of 2409 interviews were included in the analysis. The hybrid heteroscedastic model with censoring at -1 combining c-TTO and DCE data yielded the most consistent results and was used for the generation of the value set. The predicted values for all 3125 health states ranged from -0.923 to 1. The preference values were most affected by the pain/discomfort dimension. CONCLUSIONS: This is the largest EQ-5D-5L valuation study conducted so far in the world. The Indian EQ-5D-5L value set will promote the effective conduct of health technology assessment studies in India, thereby generating credible evidence for efficient resource use in healthcare.

International Valuation Protocol for the EQ-5D-Y-3L.

The EQ-5D-Y-3L is a generic, health-related, quality-of-life instrument for use in younger populations. Some methodological studies have explored the valuation of children's EQ-5D-Y-3L health states. There are currently no published value sets available for the EQ-5D-Y-3L that are appropriate for use in a cost-utility analysis. The aim of this article was to describe the development of the valuation protocol for the EQ-5D-Y-3L instrument. There were several research questions that needed to be answered to develop a valuation protocol for EQ-5D-Y-3L health states. Most important of these were: (1) Do we need to obtain separate values for the EQ-5D-Y-3L, or can we use the ones from the EQ-5D-3L? (2) Whose values should we elicit: children or adults? (3) Which valuation methods should be used to obtain values for child's health states that are anchored in Full health = 1 and Dead = 0? The EuroQol Research Foundation has pursued a research programme to provide insight into these questions. In this article, we summarized the results of the research programme concluding with the description of the features of the EQ-5D-Y-3L valuation protocol. The tasks included in the protocol for valuing EQ-5D-Y-3L health states are discrete choice experiments for obtaining the relative importance of dimensions/levels and composite time-trade-off for anchoring the discrete choice experiment values on 1 = Full Health and 0 = Dead. This protocol is now available for use by research teams to generate EQ-5D-Y-3L value sets for their countries allowing the implementation of a cost-utility analysis for younger populations.

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.

How Prevalent Are Implausible EQ-5D-5L Health States and How Do They Affect Valuation? A Study Combining Quantitative and Qualitative Evidence.

BACKGROUND: When designing a valuation study, a criterion that has been used for selecting health states for direct valuation is whether the health states are plausible for respondents, because it is assumed that inclusion of implausible states would compromise data quality. OBJECTIVES: To understand which health states are implausible, and how their values differ from the values of the plausible counterparts. METHODS: One thousand six hundred Chinese students valued all 3125 health states of the 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) using the EuroQol visual analogue scale. Of these, 890 students also indicated whether each valued state was implausible or not using a binary scale. Additional qualitative interviews were conducted concerning the thought processes involved in the valuation of implausible states. We calculated an implausible score for each state. Then we examined the effect of implausibility on visual analogue scale values by fitting 2 regression models. Two independent researchers analyzed the qualitative transcripts using thematic analysis. RESULTS: Approximately 30% of the EQ-5D-5L health states were rated as implausible by at least 50% of the respondents, but there was substantial heterogeneity in views about the plausibility of EQ-5D-5L states. Health states with dimensions that conflicted were more likely to be judged as implausible states. Health states that respondents deemed as implausible were more difficult to value and had lower values. CONCLUSIONS: When respondents found the EQ-5D states to be implausible, they tended to give them lower values. Nevertheless, completely excluding implausible states from a valuation study is not possible because there is a lack of agreement among respondents on which states are implausible.

The Fold-in, Fold-out Design for DCE Choice Tasks: Application to Burden of Disease.

Background In discrete-choice experiments (DCEs), choice alternatives are described by attributes. The importance of each attribute can be quantified by analyzing respondents' choices. Estimates are valid only if alternatives are defined comprehensively, but choice tasks can become too difficult for respondents if too many attributes are included. Several solutions for this dilemma have been proposed, but these have practical or theoretical drawbacks and cannot be applied in all settings. The objective of the current article is to demonstrate an alternative solution, the fold-in, fold-out approach (FiFo). We use a motivating example, the ABC Index for burden of disease in chronic obstructive pulmonary disease (COPD). Methods Under FiFo, all attributes are part of all choice sets, but they are grouped into domains. These are either folded in (all attributes have the same level) or folded out (levels may differ). FiFo was applied to the valuation of the ABC Index, which included 15 attributes. The data were analyzed in Bayesian mixed logit regression, with additional parameters to account for increased complexity in folded-out questionnaires and potential differences in weight due to the folding status of domains. As a comparison, a model without the additional parameters was estimated. Results Folding out domains led to increased choice complexity for respondents. It also gave domains more weight than when it was folded in. The more complex regression model had a better fit to the data than the simpler model. Not accounting for choice complexity in the models resulted in a substantially different ABC Index. Conclusion Using a combination of folded-in and folded-out attributes is a feasible approach for conducting DCEs with many attributes.

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.

Effect of Health State Sampling Methods on Model Predictions of EQ-5D-5L Values: Small Designs Can Suffice.

OBJECTIVE: The current five-level EQ-5D (EQ-5D-5L) valuation protocol requires the valuation of 86 states. It has been demonstrated that the selection of empirically valued health states affects the extrapolated values in three-level EQ-5D (EQ-3D-3L). In this investigation, we aim to compare the performance of the current EQ-5D-5L valuation design with other designs. STUDY DESIGN: 1603 university students participated in a valuation study using a visual analog scale (VAS) to produce values for all EQ-5D-5L states. Different designs were generated to test their prediction accuracy. METHODS: Subsamples of the dataset were used to mimic data obtained from a particular design; the remaining dataset was used as the validation set. In addition to EuroQol Group Valuation Technology (EQ-VT) design, alternative subsamples and designs were created using random, orthogonal, and "optimizing D-efficiency" sampling methods. The root mean squared error (RMSE) was used as the measure of prediction accuracy. RESULTS: The EuroQol Group Valuation Technology (EQ-VT) design showed an average RMSE of 3.44 on EQ-VAS, for all 3125 health states combined. Notably, a 25-state orthogonal design performed similarly to the EQ-VT design, with a smaller RMSE of 3.40, and was thus the most efficient design. One caveat with respect to the orthogonal design was that it did not predict the mild states well. CONCLUSIONS: Our study supports the EQ-VT design. Smaller designs were identified with similar overall prediction accuracy. It is worth investigating whether issues with misprediction of mild states can be resolved, as the use of smaller size designs would reduce the cost of the valuation of EQ-5D-5L considerably.

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.

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.

Effect of Level Overlap and Color Coding on Attribute Non-Attendance in Discrete Choice Experiments.

OBJECTIVE: The aim of this study was to test the hypothesis that level overlap and color coding can mitigate or even preclude the occurrence of attribute nonattendance in discrete choice experiments. METHODS: A randomized controlled experiment with five experimental study arms was designed to investigate the independent and combined impact of level overlap and color coding on respondents' attribute nonattendance. The systematic differences between the study arms allowed for a direct comparison of observed dropout rates and estimates of the average number of attributes attended to by respondents, which were obtained by using augmented mixed logit models that explicitly incorporated attribute non-attendance. RESULTS: In the base-case study arm without level overlap or color coding, the observed dropout rate was 14%, and respondents attended, on average, only two out of five attributes. The independent introduction of both level overlap and color coding reduced the dropout rate to 10% and increased attribute attendance to three attributes. The combination of level overlap and color coding, however, was most effective: it reduced the dropout rate to 8% and improved attribute attendance to four out of five attributes. The latter essentially removes the need to explicitly accommodate for attribute non-attendance when analyzing the choice data. CONCLUSIONS: On the basis of the presented results, the use of level overlap and color coding are recommendable strategies to reduce the dropout rate and improve attribute attendance in discrete choice experiments.

Selecting Health States for EQ-5D-3L Valuation Studies: Statistical Considerations Matter.

BACKGROUND: For many countries, the three-level EuroQol five-dimensional questionnaire (EQ-5D-3L) value sets have been established to estimate health state utilities. To generate these value sets, researchers first collect values for a subset of preselected health states from a panel representing the general public, and then use a prediction algorithm to generate values for all 243 states. High prevalence of a health state in daily practice has historically been a key criterion in selecting a subset of health states as the observed set. More recently, other criteria have been suggested, especially approaches based on statistical criteria such as randomization and orthogonality. OBJECTIVES: To evaluate the validity and accuracy of both the earlier and newer criteria, in terms of prediction of values for all the health states and of the values of common health states in particular. METHODS: We used a pre-existing data set that contained visual analogue scale values from 126 students, each of whom valued all 243 EQ-5D-3L states. Then, we generated a series of designs and subsequently modeled the data with respect to each design. Some of these designs were used in the past; for example, the Measurement and Valuation of Health approach was included. Others were newly generated. The performance of different designs was evaluated in terms of the lowest root mean squared error for all health states taken together, and separately for common and rare states. Classification as common or rare was based on the frequency of the states' occurrence in three patient and population data sets pooled together (N = 5269). RESULTS: The orthogonal design with 54 health states produced the lowest root mean squared errors. Over-representation of common health states in a design did not improve the estimations for these states. The published designs performed the worst, whereas the random selection designs were good on average. Nevertheless, the performance of the random selection designs showed more variance compared with orthogonal designs, because some of the former designs did not display appropriate balance. CONCLUSIONS: The published designs gave rise to large estimation errors for the extrapolated EQ-5D-3L health states. The orthogonal design focusing on statistical efficiency showed its superiority. Overall, when weighing up design properties, increased statistical efficiency outweighs an increased error rate, if any, in rare health states.

Choice Defines Value: A Predictive Modeling Competition in Health Preference Research.

OBJECTIVE: To identify which specifications and approaches to model selection better predict health preferences, the International Academy of Health Preference Research (IAHPR) hosted a predictive modeling competition including 18 teams from around the world. METHODS: In April 2016, an exploratory survey was fielded: 4074 US respondents completed 20 out of 1560 paired comparisons by choosing between two health descriptions (e.g., longer life span vs. better health). The exploratory data were distributed to all teams. By July, eight teams had submitted their predictions for 1600 additional pairs and described their analytical approach. After these predictions had been posted online, a confirmatory survey was fielded (4148 additional respondents). RESULTS: The victorious team, "Discreetly Charming Econometricians," led by Michal Jakubczyk, achieved the smallest χ2, 4391.54 (a predefined criterion). Its primary scientific findings were that different models performed better with different pairs, that the value of life span is not constant proportional, and that logit models have poor predictive validity in health valuation. CONCLUSIONS: The results demonstrated the diversity and potential of new analytical approaches in health preference research and highlighted the importance of predictive validity in health valuation.

ABC Index: quantifying experienced burden of COPD in a discrete choice experiment and predicting costs.

OBJECTIVE: The Assessment of Burden of COPD (ABC) tool supports shared decision making between patient and caregiver. It includes a coloured balloon diagram to visualise patients' scores on burden indicators. We aim to determine the importance of each indicator from a patient perspective, in order to calculate a weighted index score and investigate whether that score is predictive of costs. DESIGN: Discrete choice experiment. SETTING AND PARTICIPANTS: Primary care and secondary care in the Netherlands. 282 patients with chronic obstructive pulmonary disease (COPD) and 252 members of the general public participated. METHODS: Respondents received 14 choice questions and indicated which of two health states was more severe. Health states were described in terms of specific symptoms, limitations in physical, daily and social activities, mental problems, fatigue and exacerbations, most of which had three levels of severity. Weights for each item-level combination were derived from a Bayesian mixed logit model. Weights were rescaled to construct an index score from 0 (best) to 100 (worst). Regression models were used to find a classification of this index score in mild, moderate and severe that was discriminative in terms of healthcare costs. RESULTS: Fatigue, limitations in moderate physical activities, number of exacerbations, dyspnoea at rest and fear of breathing getting worse contributed most to the burden of disease. Patients assigned less weight to dyspnoea during exercise, listlessness and limitations with regard to strenuous activities. Respondents from the general public mostly agreed. Mild, moderate and severe burden of disease were defined as scores <20, 20-39 and ≥40. This categorisation was most predictive of healthcare utilisation and annual costs: €1368, €2510 and €9885, respectively. CONCLUSIONS: The ABC Index is a new index score for the burden of COPD, which is based on patients' preferences. The classification of the index score into mild, moderate and severe is predictive of future healthcare costs. TRIAL REGISTRATION NUMBER: NTR3788; Post-results.

Toward Explicit Prioritization for the Caribbean: An EQ-5D Value Set for Trinidad and Tobago.

BACKGROUND: Resource allocation decision making in the Caribbean can be greatly enhanced by the introduction of cost per quality-adjusted life-year (QALY) analysis on the basis of local preferences. In the valuation literature there have been recommendations for the elicitation methods of the EuroQol five-dimensional questionnaire (EQ-5D) that combine discrete-choice experiment (DCE) for bulk valuation with a time trade-off component for rescaling. OBJECTIVES: To create a three-level EQ-5D value set for Trinidad and Tobago using an elicitation method that takes into account the local constraints, and that can be easily deployed in other Caribbean islands. METHODS: A D-efficient DCE was completed by a representative sample of 307 adults. A time trade-off procedure was used to obtain values for rescaling the DCE model on a scale anchored at 0 (dead) and 1 (full health). RESULTS: A mixed logit analysis of the DCE data produced an internally valid model that is similar to the results obtained in earlier pilot studies. CONCLUSIONS: This EQ-5D value set allows cost per QALY analyses to be carried out on the basis of preferences from Trinidad and Tobago, and the approach to the DCE design can be taken for similar value sets to be created in the small, resource-constrained health systems of the Caribbean. Some guidelines for the initial application and introduction of cost per QALY analysis into the Trinidad and Tobago health system are also presented.