Characteristics Predicting Short-Term and Long-Term Health-Related Quality of Life in Patients with Esophageal Cancer After Neoadjuvant Chemoradiotherapy and Esophagectomy.

BACKGROUND: Esophagectomy is associated with lasting effect on health-related quality of life (HRQOL). Patients desire detailed information on the expected impact of treatment on their postoperative HRQOL. The aim of the present study is to identify clinicopathological characteristics predictive for changes in short-term and long-term HRQOL after neoadjuvant chemoradiotherapy (nCRT) and surgery. METHODS: HRQOL was measured using EORTC-QLQ-C30 and QLQ-OES24 questionnaires prior to nCRT, three, six, nine and twelve months postoperatively and at a minimum of six years postoperatively. Based on previous experience and available literature, several subgroups were predefined for different clinicopathological characteristics: baseline global HRQOL, WHO performance status, histology, tumor stage and tumor location. The primary endpoints of the present study were the change compared to baseline in the HRQOL dimensions physical functioning and eating problems. Secondary endpoints were global HRQOL, fatigue and emotional problems. RESULTS: In total, 134 (76%) of 177 patients who received HRQOL questionnaires, responded at baseline. Patients who reported a high baseline global HRQOL had a more severe deterioration in eating problems (+14.5 to + 18.0), global HRQOL (-16.0 to -28.0) and fatigue (+10.5 to +14.9) up to six years postoperatively compared to patients who reported a low baseline global HRQOL. Patients who had stage 2 tumor (UICC 6th edition) had a more severe deterioration in eating problems (+14.6 to +19.0) and global HRQOL (-10.1 to -17.1) than patients who had stage 3 tumor. CONCLUSIONS: The results suggest that patients with locally advanced esophageal cancer in favorable condition at baseline decline more in terms of various HRQOL outcomes.

Accounting for Unobservable Preference Heterogeneity and Evaluating Alternative Anchoring Approaches to Estimate Country-Specific EQ-5D-Y Value Sets: A Case Study Using Spanish Preference Data.

OBJECTIVES: The EuroQol Group published the EQ-5D-Y valuation protocol that recommends 2 valuation techniques to elicit preferences: composite time trade-off (C-TTO) and discrete choice experiments (DCEs). The protocol left the decision of what modeling approach to use open for researchers. Our aims were to explore modeling strategies allowing generation of EQ-5D-Y value sets and to produce an EQ-5D-Y Spanish value set. METHODS: We used EQ-5D-Y DCE and C-TTO data collected in Spain following the protocol and adopted a staged approach for our modeling exercise. First, we selected the best performing DCE latent class model and evaluated models from 2 to 10 classes. We selected the preferred model based on best goodness of fit in terms of the Bayesian information criterion. We considered 2 anchoring approaches to estimate utility values: (1) pits state anchoring and (2) hybrid models (using all available C-TTO responses). All analysis were weighted to be representative of the Spanish population. RESULTS: We collected 1005 DCE and 200 C-TTO interviews. We selected a DCE model including 4 classes. Hybrid models using all available C-TTO observations produced a narrower range of values than the pits state anchoring approach. CONCLUSIONS: In this article, we have presented an EQ-5D-Y value set that can be used for cost-utility analysis in Spain. The international EQ-5D-Y valuation protocol should be updated to include a different set of health states for the C-TTO experiment if researchers wish to use alternative anchoring approaches to the "pits state."

Does Changing the Age of a Child to be Considered in 3-Level Version of EQ-5D-Y Discrete Choice Experiment-Based Valuation Studies Affect Health Preferences?

OBJECTIVES: There has been some debate about the choice of perspective and the age of the child considered when completing preference elicitation tasks in the 3-level version of EQ-5D-Y (EQ-5D-Y-3L) valuation protocol. This study aimed to clarify the impact on latent scale EQ-5D-Y-3L values of varying the age of the child experiencing the health state considered by respondents completing the discrete choice experiment (DCE) tasks of the protocol. METHODS: We conducted an online DCE with a representative sample of 1000 adults in the United Kingdom and 1000 adults in the United States. Respondents selected the health state they prefer from a series of DCE paired EQ-5D-Y-3L health state comparisons using their own perspective and that of a hypothetical child from the following age groups: "5-7 years old," "8-10 years old," "11-13 years old," and "14-15 years old." Data analysis was conducted using separate multinomial logit models for each perspective and country. We also estimated combined models including data from each possible pair of perspectives and used interactions between EQ-5D-Y-3L levels and perspective to determine whether any differences were statistically significant. RESULTS: No statistically significant differences in coefficients between perspectives were found in the United States. In the United Kingdom, there were differences between the own perspective and the 5 to 7 years old perspective (looking after myself level 3) and between the 5 to 7 years old perspective and the 8 to 10 years old perspective (usual activities level 3). CONCLUSIONS: Our results suggest that there is minimal impact on latent scale values when using different ages of the hypothetical child in the current EQ-5D-Y-3L valuation protocol.

To What Extent Do Patient Preferences Differ From General Population Preferences?

OBJECTIVES: In some countries including Germany, value sets based on general population preferences are not acceptable for decision-makers in healthcare because the impact of the reference group-general population versus patients-on utility decrements is questioned. The objective of this study was to explore potential differences in patient versus general population health preferences and a way of combining both preferences in economic evaluation. METHODS: EQ-5D-5L general population preferences were available from national value sets in Germany and Spain. Patient preferences were obtained by conducting discrete choice experiments with patients with rheumatism and patients with diabetes mellitus in Germany and Spain using an online panel. The econometric approach was based on the conditional logit framework. Latent values were anchored using the national value sets. RESULTS: A total of 1700 patients (Germany, n = 937; Spain, n = 763) were included in the analysis. In both countries, patients gave more importance to mobility, self-care, or usual activities and less importance to pain/discomfort and anxiety/depression than the general population. The size of these differences was larger in Germany than in Spain. In Germany, preferences reported by both patient groups were more similar than in Spain. CONCLUSION: Patient preferences differ from preferences derived from the general population. In contrast to the general population, patients gave more importance to the functional dimensions than to symptoms in both countries. The extent of the differences depends on the disease and the country. For countries preferring patient preferences, a possible way of incorporating the patient perspective in health state valuation was suggested and needs to be further explored.

Health-related quality of life after traumatic brain injury: deriving value sets for the QOLIBRI-OS for Italy, The Netherlands and The United Kingdom.

PURPOSE: The Quality of Life after Brain Injury overall scale (QOLIBRI-OS) measures health-related quality of life (HRQoL) after traumatic brain injury (TBI). The aim of this study was to derive value sets for the QOLIBRI-OS in three European countries, which will allow calculation of utility scores for TBI health states. METHODS: A QOLIBRI-OS value set was derived by using discrete choice experiments (DCEs) and visual analogue scales (VAS) in general population samples from the Netherlands, United Kingdom and Italy. A three-stage procedure was used: (1) A selection of health states, covering the entire spectrum of severity, was defined; (2) General population samples performed the health state valuation task using a web-based survey with three VAS questions and an at random selection of sixteen DCEs; (3) DCEs were analysed using a conditional logistic regression and were then anchored on the VAS data. Utility scores for QOLIBRI-OS health states were generated resulting in estimates for all potential health states. RESULTS: The questionnaire was completed by 13,623 respondents. The biggest weight increase for all attributes is seen from "slightly" to "not at all satisfied", resulting in the largest impact on HRQoL. "Not at all satisfied with how brain is working" should receive the greatest weight in utility calculations in all three countries. CONCLUSION: By transforming the QOLIBRI-OS into utility scores, we enabled the application in economic evaluations and in summary measures of population health, which may be used to inform decision-makers on the best interventions and strategies for TBI patients.

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.

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.

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.

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.

Valuation and Modeling of EQ-5D-5L Health States Using a Hybrid Approach.

BACKGROUND: The EQ-5D instrument is the most widely used preference-based health-related quality of life questionnaire in cost-effectiveness analysis of health care technologies. Recently, a version called EQ-5D-5L with 5 levels on each dimension was developed. This manuscript explores the performance of a hybrid approach for the modeling of EQ-5D-5L valuation data. METHODS: Two elicitation techniques, the composite time trade-off, and discrete choice experiments, were applied to a sample of the Spanish population (n=1000) using a computer-based questionnaire. The sampling process consisted of 2 stages: stratified sampling of geographic area, followed by systematic sampling in each area. A hybrid regression model combining composite time trade-off and discrete choice data was used to estimate the potential value sets using main effects as starting point. The comparison between the models was performed using the criteria of logical consistency, goodness of fit, and parsimony. RESULTS: Twenty-seven participants from the 1000 were removed following the exclusion criteria. The best-fitted model included 2 significant interaction terms but resulted in marginal improvements in model fit compared to the main effects model. We therefore selected the model results with main effects as a potential value set for this methodological study, based on the parsimony criteria. The results showed that the main effects hybrid model was consistent, with a range of utility values between 1 and -0.224. CONCLUSION: This paper shows the feasibility of using a hybrid approach to estimate a value set for EQ-5D-5L valuation data.

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

BACKGROUND: The values of the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) are elicited using composite time trade-off and discrete choice experiments. Unfortunately, data quality issues and interviewer effects were observed in the first few EQ-5D-5L valuation studies. To prevent these issues from occurring in later studies, the EuroQol Group established a cyclic quality control (QC) process. OBJECTIVES: To describe this QC process and show its impact on data quality. METHODS: A newly developed QC tool provided information about protocol compliance, interviewer effects, and mean values by health state severity. In a cyclic process, this information is initially used to evaluate whether new interviewers meet minimal quality requirements and later to provide feedback about how their performance may be improved. To investigate the impact of this cyclic process, we compared the quality of the data in Dutch and Spanish valuation studies that did not have this QC process with that in the follow-up studies in the same countries that used the QC process. Data quality was measured using protocol violations, variability between interviewers, the proportion of inconsistent responders, and clustering of composite time trade-off values. RESULTS: In Spain, protocol violations were reduced from 87% in the valuation study to 5% in the follow-up study and in the Netherlands from 20% to 8%. In both countries, interviewers performed more homogeneously in the follow-up studies. The number of inconsistent respondents was reduced by 23.2% in Spain and 23.6% in the Netherlands. Values were less clustered in the follow-up studies. CONCLUSIONS: The implementation of a strict QC process in EQ-5D-5L valuation studies increases interviewer protocol compliance and promotes data quality.

Preferred reporting items for studies mapping onto preference-based outcome measures: the MAPS statement.

BACKGROUND AND AIM: 'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MApping onto Preference-based measures reporting Standards (MAPS) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. METHODS: In the absence of previously published reporting checklists or reporting guidance documents, a de novo list of reporting items was created by a working group comprised of six health economists and one Delphi methodologist. A two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community was used to identify a list of essential reporting items from this larger list. RESULTS: From the initial de novo list of 29 candidate items, a set of 23 essential reporting items was developed. The items are presented numerically and categorised within six sections, namely (1) title and abstract; (2) introduction; (3) methods; (4) results; (5) discussion; and (6) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. CONCLUSIONS: It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by seven health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in 5 years' time.

Learning and satisficing: an analysis of sequence effects in health valuation.

OBJECTIVE: To estimate the effect of sequence on response precision and response behavior in health valuation studies. METHODS: Time trade-off (TTO) and paired comparison responses from six health valuation studies-four US, one Spanish, and one Dutch-were examined (22,225 respondents) to test whether task sequence influences response precision (e.g., rounding), response changes, and median response times. Each study used a computer-based instrument that randomized task sequence among a national sample of adults, age 18 years or older, from the general population. RESULTS: For both TTO and paired comparisons, median response times decreased with sequence (i.e., learning), but tended to flatten after the first three tasks. Although the paired comparison evidence demonstrated that sequence had no effect on response precision, the frequency of rounded TTO responses (to either 1-year or 5-year units) increased with sequence. CONCLUSIONS: Based on these results, randomizing or reducing the number of paired comparison tasks does not appear to influence response precision; however, generalizability, practicality, and precautionary considerations remain. Overall, participants learned to respond efficiently within the first three tasks and did not resort to satisficing, but may have rounded their TTO responses.

Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement.

'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication.A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document.It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time.This statement was published jointly in Applied Health Economics and Health Policy, Health and Quality of Life Outcomes, International Journal of Technology Assessment in Health Care, Journal of Medical Economics, Medical Decision Making, PharmacoEconomics, and Quality of Life Research.

PREFERRED REPORTING ITEMS FOR STUDIES MAPPING ONTO PREFERENCE-BASED OUTCOME MEASURES: THE MAPS STATEMENT.

BACKGROUND: "Mapping" onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. METHODS: In the absence of previously published reporting checklists or reporting guidance documents, a de novo list of reporting items was created by a working group comprised of six health economists and one Delphi methodologist. A two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies, and the biomedical journal editorial community was used to identify a list of essential reporting items from this larger list. RESULTS: From the initial de novo list of twenty-nine candidate items, a set of twenty-three essential reporting items was developed. The items are presented numerically and categorized within six sections, namely: (i) title and abstract, (ii) introduction, (iii) methods, (iv) results, (v) discussion, and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. CONCLUSIONS: It is anticipated that the MAPS statement will improve the clarity, transparency. and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by seven health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time.

Multinational evidence of the applicability and robustness of discrete choice modeling for deriving EQ-5D-5L health-state values.

AIMS: To investigate the feasibility of discrete choice experiments for valuing EQ-5D-5L states using computer-based data collection, the consistency of the estimated regression coefficients produced after modeling the preference data, and to examine the similarity of the values derived across countries. METHODS: Data were collected in Canada, England, The Netherlands, and the United States (US). Interactive software was developed to standardize the format of the choice tasks across countries, except for face-to-face interviewing in England. The choice task required respondents to choose between 2 suboptimal health states. A Bayesian design was used to generate 200 pairs of states that were randomly grouped into 20 blocks. Each respondent completed 1 block of 10 pairs. A main-effects probit model was used to estimate regression coefficients and to derive values. RESULTS: Approximately 400 respondents participated from each country. The mean time to perform 1 choice task was between 29.2 (US) and 45.2 (England) seconds. All regression coefficients were statistically significant, except level 2 for Usual Activities in The Netherlands (P=0.51). Predictions for the complete set of 3125 EQ-5D-5L health states were similar for the 4 countries. Intraclass correlation coefficients between the countries were high: from 0.80 (England vs. US) through 0.98 (Canada vs. US) CONCLUSIONS: Derivation of value sets from the general population using computer-based choice tasks for the EQ-5D-5L is feasible. Parameter estimates were generally consistent and logical, and health-state values were similar across the 4 countries.

A program of methodological research to arrive at the new international EQ-5D-5L valuation protocol.

OBJECTIVES: To describe the research that has been undertaken by the EuroQol Group to improve current methods for health state valuation, to summarize the results of an extensive international pilot program, and to outline the key elements of the five-level EuroQol five-dimensional (EQ-5D-5L) questionnaire valuation protocol, which is the culmination of that work. METHODS: To improve on methods of health state valuation for the EQ-5D-5L questionnaire, we investigated the performance of different variants of time trade-off and discrete choice tasks in a multinational setting. We also investigated the effect of three modes of administration on health state valuation: group interviews, online self-completion, and face-to-face interviews. RESULTS: The research program provided the basis for the EQ-5D-5L questionnaire valuation protocol. Two different types of tasks are included to derive preferences: a newly developed composite time trade-off task and a forced-choice paired comparisons discrete choice task. Furthermore, standardized blocked designs for the selection of the states to be valued by participants were created and implemented together with all other elements of the valuation protocol in a digital aid, the EuroQol Valuation Technology, which was developed in conjunction with the protocol. CONCLUSIONS: The EuroQol Group has developed a standard protocol, with accompanying digital aid and interviewer training materials, that can be used to create value sets for the EQ-5D-5L questionnaire. The use of a well-described, consistent protocol across all countries enhances the comparability of value sets between countries, and allows the exploration of the influence of cultural and other factors on health state values.

The valuation of the EQ-5D in Portugal.

PURPOSE: The EQ-5D is a preference-based measure widely used in cost-utility analysis (CUA). Several countries have conducted surveys to derive value sets, but this was not the case for Portugal. The purpose of this study was to estimate a value set for the EQ-5D for Portugal using the time trade-off (TTO). METHODS: A representative sample of the Portuguese general population (n = 450) stratified by age and gender valued 24 health states. Face-to-face interviews were conducted by trained interviewers. Each respondent ranked and valued seven health states using the TTO. Several models were estimated at both the individual and aggregated levels to predict health state valuations. Alternative functional forms were considered to account for the skewed distribution of these valuations. RESULTS: The models were analyzed in terms of their coefficients, overall fit and the ability for predicting the TTO values. Random effects models were estimated using generalized least squares and were robust across model specification. The results are generally consistent with other value sets. CONCLUSION: This research provides the Portuguese EQ-5D value set based on the preferences of the Portuguese general population as measured by the TTO. This value set is recommended for use in CUA conducted in Portugal.

EQ-5D Portuguese population norms.

OBJECTIVES: The EQ-5D is a widely used preference-based measure. Normative data can be used as references to analyze the effects of healthcare, determine the burden of disease and enable regional or country comparisons. Population norms for the EQ-5D exist for other countries but have not been previously published for Portugal. The purpose of this study was to derive EQ-5D Portuguese population norms. METHODS: The EQ-5D was applied by phone interview to a random sample of the Portuguese general population (n = 1,500) stratified by age, gender and region. The Portuguese value set was used to derive the EQ-5D index. RESULTS: Mean values were computed by gender and age groups, marital status, educational attainment, region and other variables to obtain the EQ-5D Portuguese norms. Health status declines with advancing age, and women reported worse health status than men. These results are similar to other EQ-5D population health studies. CONCLUSION: This study provides Portuguese population health-related quality of life data measured by the EQ-5D that can be used as population norms. These norms can be used to inform Portuguese policy makers, health care professionals and researchers in issues related to health care policy and planning and quantification of treatment effects on health status.

Lead time TTO: leading to better health state valuations?

Preference elicitation tasks for better than dead (BTD) and worse than dead (WTD) health states vary in the conventional time trade-off (TTO) procedure, casting doubt on uniformity of scale. 'Lead time TTO' (LT-TTO) was recently introduced to overcome the problem. We tested different specifications of LT-TTO in comparison with TTO in a within-subject design. We elicited preferences for six health states and employed an intertemporal ranking task as a benchmark to test the validity of the two methods. We also tested constant proportional trade-offs (CPTO), while correcting for discounting, and the effect of extending the lead time if a health state is considered substantially WTD. LT-TTO produced lower values for BTD states and higher values for WTD states. The validity of CPTO varied across tasks, but it was higher for LT-TTO than for TTO. Results indicate that the ratio of lead time to disease time has a greater impact on results than the total duration of the time frame. The intertemporal ranking task could not discriminate between TTO and LT-TTO.