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

Putting the Choice in Choice Tasks: Incorporating Preference Elicitation Tasks in Health Preference Research

Choice-based preference elicitation methods such as the discrete choice experiment (DCE) present hypothetical choices to respondents, with an expectation that these hypothetical choices accurately reflect a 'real world' health-related decision context and that consequently the choice data can be held to be a true representation of the respondent's health or treatment preferences. For this to be the case, careful consideration needs to be given to the format of the choice task in a choice experiment. The overarching aim of this paper is to highlight important aspects to consider when designing and 'setting up' the choice tasks to be presented to respondents in a DCE. This includes the importance of considering the potential impact of format (e.g. choice context, choice set presentation and size) as well as choice set content (e.g. labelled and unlabelled choice sets and inclusion of reference alternatives) and choice questions (stated choice versus additional questions designed to explore complete preference orders) on the preference estimates that are elicited from studies. We endeavoure to instil a holistic approach to choice task design that considers format alongside content, experimental design and analysis.

Creating a Multiply Imputed Value Set for the EQ-5D-5L in Canada: State-Level Misspecification Terms Are Needed to Characterize Parameter Uncertainty Correctly

BACKGROUND

Parameter uncertainty in EQ-5D-5L value sets often exceeds the instrument's minimum important difference, yet this is routinely ignored. Multiple imputation (MI) accounts for parameter uncertainty in the value set; however, no valuation study has implemented this methodology. Our objective was to create a Canadian MI value set for the EQ-5D-5L, thus enabling users to account for parameter uncertainty in the value set.

METHODS

Using the Canadian EQ-5D-5L valuation study (N = 1,073), we first refit the original model followed by models with state-level misspecification. Models were compared based on the adequacy of 95% credible interval (CrI) coverage for out-of-sample predictions. Using the best-fitting model, we took 100 draws from the posterior distribution to create 100 imputed value sets. We examined how much the standard error of the estimated mean health utilities increased after accounting for parameter uncertainty in the value set by using the MI and original value sets to score 2 data sets: 1) a sample of 1,208 individuals from the Canadian general public and 2) a sample of 401 women with breast cancer.

RESULTS

The selected model with state-level misspecification outperformed the original model (95% CrI coverage: 94.2% v. 11.6%). We observed wider standard errors for the estimated mean utilities on using the MI value set for both the Canadian general public (MI: 0.0091; original: 0.0035) and patients with breast cancer (MI: 0.0169; original: 0.0066).

DISCUSSION AND CONCLUSIONS

We provide 1) the first MI value sets for the EQ-5D-5L and 2) code to construct MI value sets while accounting for state-level model misspecification. Our study suggests that ignoring parameter uncertainty in value sets leads to falsely narrow SEs.

HIGHLIGHTS

Value sets for health state utility instruments are estimated subject to parameter uncertainty; this parameter uncertainty may exceed the minimum important difference of the instrument, yet it is not fully captured using current methods.This study creates the first multiply imputed value set for a multiattribute utility instrument, the EQ-5D-5L, to fully capture this parameter uncertainty.We apply the multiply imputed value set to 2 data sets from 1) the Canadian general public and 2) women with invasive breast cancer.Scoring the EQ-5D-5L using a multiply imputed value set led to wider standard error estimates, suggesting that the current practice of ignoring parameter uncertainty in the value set leads to falsely low standard errors.Our work will be of interest to methodologists and developers of the EQ-5D-5L and users of the EQ-5D-5L, such as health economists, researchers, and policy makers.

Behind the Scenes: A Qualitative Investigation of Interviewers' Performance in EQ-5D Valuation Studies

BACKGROUND

The EuroQol Valuation Technology (EQ-VT) protocol is currently employed by the valuation studies of the EQ family of instruments worldwide. To date, all the evidence in support of the quality control (QC) originates from quantitative indicators.

OBJECTIVE

We aimed to explore interviewers' conversational patterns in EQ-VT interviews, beyond quantitative QC indicators, and to provide a preliminary exploration of how the interaction between interviewer and respondent impacts data quality.

METHODS

Two researchers transcribed and independently coded 24 video-recorded interviews from the Italian EQ-5D-5L valuation study, adopting the conversational analysis framework. The analysis identified positive and negative 'patterns' of conversational practice. These were categorized into themes and sub-themes and were used to score a random sample of 42 video-recorded interviews conducted at different time points by seven interviewers.

RESULTS

The conversational analysis identified 20 positive and 14 negative interview patterns, which were grouped into two main themes (i.e., task execution and communication skills). Positive items included appending questions that stimulated respondents' engagement, providing different explanations for an unclear aspect, supporting the participant with useful information for completing the tasks, and increasing the interview's coherence by confirming the respondent answers. Negative patterns included moving forward in the exercise without making sure that the respondent understood, trying to force an answer from the respondent, speaking too fast, and providing incomplete or incorrect explanations of the task. Most interviewers exhibited a moderate increase in positive patterns or a decrease in negative patterns over time. A certain degree of consistency between the quantitative QC results and the qualitative scoring deriving from the interviewer-respondent interaction was observed, with the best and worst performers of the qualitative scoring showing good and bad scores on key QC items, respectively.

CONCLUSIONS

The identified positive and negative patterns may be useful to inform the training material of EQ-VT studies worldwide and complement the existing QC process.

Valuation of EQ-5D-5L in the Kingdom of Saudi Arabia: A National Representative Study

OBJECTIVES

To estimate a Saudi-specific value set for the EQ-5D-5L questionnaire using the EuroQol Valuation Technology program and the EuroQol Group's standard protocol.

METHODS

Participants were quota-sampled from the Saudi adult population based on residency location, age group, gender, education level, and employment status. The participants were guided through the completion of composite time trade-off (cTTO) and discrete choice experiment (DCE) tasks by trained interviewers using EuroQol Valuation Technology software. Quality control (QC) measures were used to ensure good data quality. Random intercept and Tobit models analyzed the cTTO data, as well as models correcting for heteroskedasticity. DCE data were analyzed using conditional logit models, whereas hybrid models were used to analyze the cTTO and DCE data jointly. To evaluate model performance, prediction accuracy, logical consistency, significance level, and goodness of fit were used.

RESULTS

The valuation study included a representative sample of the Saudi population (N = 1000). The hybrid heteroskedastic model without a constant was chosen as the preferred model for generating the value set. The predicted values ranged from -0.683 for the worst health state ("55555") to 1 for the full health state ("11111"). Pain and discomfort had the largest impact on health-state preference values, whereas usual activities had the least.

CONCLUSION

The value set for the Kingdom of Saudi Arabia is the first value set for the EQ-5D-5L for any country in the Middle East. The value set can be used in Saudi health system economic evaluations and decision making.

A Methodological Study to Compare Alternative Modes of Administration with Value EQ-5D Using Preference-Elicitation Techniques

OBJECTIVES

Time trade-off (TTO) and discrete choice experiment (DCE) preference-elicitation techniques can be administered using face-to-face interviews (F2F), unassisted online (UO) surveys, or remote-assisted (RA) interviews. The objective of this study was to explore how the mode of administration affects the quality and reliability of preference-elicitation data.

METHODS

EQ-5D-5L health states were valued using composite TTO (cTTO) and DCE approaches by the UK general population. Participants were allocated to 1 of 2 study groups. Group A completed both F2F and UO surveys (n = 271), and group B completed both RA and UO surveys (n = 223). The feasibility of survey completion and the reliability and face-validity of data collected were compared across all modes of administration.

RESULTS

Fewer participants reported receiving sufficient guidance on the cTTO tasks during the UO survey compared with the 2 assisted modes. Participants across all modes typically reported receiving sufficient guidance on the DCE tasks. cTTO data were less reliable from the UO survey compared with both assisted modes, but there were no differences in DCE data reliability. cTTO data from all modes demonstrated face-validity; however, the UO survey produced higher utilities for moderate and severe health states than both assisted modes. Both F2F and RA modes provided comparably reliable data.

CONCLUSIONS

The reliability of DCE data is not affected by the mode of administration. Interviewer-assisted modes of administration (F2F or RA) yield more reliable cTTO data than unassisted surveys. Both F2F and RA surveys produced similar-quality data.

Comparing heuristic valuation processes between health state valuation from child and adult perspectives

OBJECTIVES

Health state valuation assumes that respondents trade off between all aspects of choice tasks and maximize their utility. Yet, respondents may use heuristic valuation processes, i.e., strategies to simplify or avoid the trade-offs that are core to health state valuation. The objective of this study is to explore if heuristic valuation processes are more prevalent for valuation from a 10-year-old child's perspective compared to the use of an adult perspective.

METHODS

We reused existing data in which EQ-5D health states were valued from adult and child perspectives with composite time trade-off (cTTO) and discrete choice experiment (DCE) tasks. Our analyses focused on comparing completion time and responding patterns across both perspectives. We also explored how reflective of a set of heuristic strategies respondents' choices were in both perspectives.

RESULTS

We found no evidence for systematic differences in completion time across perspectives. Generally, we find different responding patterns in child perspectives, e.g., more speeding, dominance violations, and clustering of utilities at 1.0, 0.8, and 0. Very few heuristic strategies provide a coherent explanation for the observed DCE responses.

CONCLUSION

Our results provide some, albeit indirect, evidence for differences in heuristic valuation processes between perspectives, although not across all data sources. Potential effects of heuristic valuation processes, such as transfer of responsibility, may be identified through studying responding patterns in cTTO and DCE responses.

Canada population norms for the EQ-5D-5L

OBJECTIVE

In Canada, population norms are only available for 2 provinces, Alberta and Quebec. The objective of this study was to derive the population norms for the EQ-5D-5L based on a representative sample of the Canadian general population.

METHODS

Data from the Canadian EQ-5D-5L valuation study, a cross-sectional study, were used. A quota sampling method was used to recruit a representative sample of the Canadian general population in terms of age, sex, and education. EQ-5D-5L utilities and EQ VAS were summarized using descriptive statistics and the impact of demographic characteristics on the EQ-5D-5L utilities was evaluated using statistical hypothesis testing and Tobit regression.

RESULTS

1207 eligible participants were included in the analysis. Pain/discomfort (53.1%) was the most frequently reported domain with any problem, and self-care (7.6%) domain was the least. The mean (standard deviation [SD]) EQ-5D-5L utility was 0.864 (0.121) and the mean (SD) EQ VAS was 82.3 (14.23). The highest mean EQ-5D-5L utility was 0.881 in age group 25-34 while the lowest was 0.839 in age group 55-64. Participants who had full-time employment, were married, a higher annual household income and no chronic health conditions had significantly higher EQ-5D-5L utilities.

CONCLUSION

This article reports the first Canadian population norms for the EQ-5D-5L and can be used as population references for economic evaluations and clinical research.

Testing 2 Alternative Time Trade-Off Methods for Valuation of Children's Health States

OBJECTIVES

Composite time trade-off (cTTO) values for EQ-5D-Y-3L health states tend to be high, raising concerns about sensitivity particularly for mild or moderate health states. We conceptualized and pilot tested 2 alternative time trade-off (TTO) variants: the caregiver TTO (CGTTO) and lag-time TTO (LTTO).

METHODS

We collected CGTTO and LTTO data in China for 10 EQ-5D-Y-3L health states and compared the resulting values, respondent feedback, and task completion times with those from an EQ-5D-Y-3L valuation study using cTTO. We also examined how age and parental status of respondents could affect TTO values.

RESULTS

A total of 304 participants were included in this study. Overall, cTTO showed statistically better results in all feedback questions. On a 5-point Likert scale where lower score means greater agreement, the mean (SD) feedback scores for cTTO, LTTO, and CGTTO were 1.18 (0.58), 1.45 (0.91), and 1.65 (1.02) for "easy to understand"; 1.45 (0.91), 1.94 (1.08), and 1.86 (1.24) for "easy to differentiate"; and 3.61 (1.29), 2.97 (1.33), and 3.02 (1.50) for "difficult to decide," respectively. The mean (SD) TTO values of all 10 states were 0.463 (0.494), 0.387 (0.555), and 0.123 (0.710) for cTTO, LTTO, and CGTTO, respectively. The effects of age and parental status on TTO values differed by the 3 methods.

CONCLUSIONS

LTTO and CGTTO produce values with good characteristics and merit further investigation. Researchers need to be aware of the differences in design and values when using the TTO method to value children's health states.

Exploring non-iterative time trade-off methods for valuation of EQ-5D-5L health states

INTRODUCTION

The composite time trade-off (cTTO) method is used as the primary method for valuing EQ-5D-5L health states, but it requires intensive interviewer training and stringent quality control, which increases the burden of conducting cTTO studies. In this study, two non-iterative variants of the TTO method, non-stopping TTO (nTTO) and open-ended TTO (oTTO), were tested head-to-head with the cTTO method aiming to reduce the administration burden.

METHODS

31 EQ-5D-5L health states from an orthogonal array was selected and valued by a general public sample in China. Data were collected by 7 interviewers with all interviewers performed an equal number of interviews using all three TTO methods. We compared the value distribution, logical consistency, administration burden, and modeling performance of these three TTO methods.

RESULTS

In total, 422 participants participated in the valuation interviews, with 139 using the nTTO method, 140 using the oTTO method, and 143 using the cTTO method. Both oTTO and nTTO methods saved around 10 min for conducting an interview. The mean values of three methods were similar with each method showed different characteristics in their value distributions. cTTO outperformed the other two methods in terms of modeling performance.

DISCUSSION

Both non-iterative TTO methods showed potential for valuing EQ-5D health states, although their data distributions and modeling performance were inferior to the cTTO method. The results of this study showed the potential of these two alternative non-iterative TTO methods.

Do people with different sociodemographic backgrounds value their health differently? Evaluating the role of positional objectivity

Objective

The fundamental disconnect between the actual and the perceived health of an individual raises considerable skepticism on the self-reported health data as it may be confounded by an individual's socio-economic status. In this light, the present study aims to assess if people with different sociodemographic backgrounds value their health differently.

Methods

The health-state valuation using time-trade off was performed in a cross-sectional survey among a representative sample of 2,311 adults from India. Individuals were selected using a multistage stratified random sampling from five Indian states to elicit their present health-state, and to perform the health-state valuation exercise using computer assisted personal interviewing. A single block of standardized health-states was valued by multiple individuals, each belonging to different socio-demographic group. The difference in the valuation of health was assessed using bivariate analysis. The impact of different sociodemographic factors on the health-state valuation was evaluated using Tobit regression model.

Results

Differences in the valuation of health were observed among different groups of age, religion, family type, state of residence, substance abuse, presence of ailments at the time of valuation, and number of dependent members in the household. Even after controlling for the severity of the administered health states, factors having a significant association with the valuation of health are age, religion, state of residence, substance abuse, family type, number of dependent members in the household, and presence of chronic or both acute and chronic ailments. Younger individuals place a higher value to their health as compared to their older counterparts. As compared to a healthy individual, a person with ailments rates the same health-state as worse.

Conclusion

Inequalities in self-reported ill-health cannot be attributed to positional objectivity; age, religion, state of residence, substance abuse, family type, dependents, and ailments impact individual health valuation.

EQ-5D-5L Value Set for Slovenia

OBJECTIVES

The aim of this valuation study was to produce a value set to support the use of EQ-5D-5L data in decision making in Slovenia.

METHODS

The study design followed the published EuroQol research protocol, and a quota sample was defined according to age, sex, and region. Overall, 1012 adult respondents completed 10 time trade-off and seven discrete choice experiment tasks in face-to-face interviews. The Tobit model was used to analyse the composite time trade-off (cTTO) data in order to generate values for the 3125 EQ-5D-5L health states.

RESULTS

The data showed logical consistency, with more severe states being given lower values. The greatest disutility was shown in the pain/discomfort and anxiety/depression dimensions. In the EQ-5D-5L value set, the values range from -1.09 to 1. With the exception of UA5 (unable to perform usual activities), all other levels on all health dimensions were statistically different from 0 and from each other. Compared with the existing EQ-5D-3L value set, there is a slightly lower share of 'worse than dead' states (32.1% compared with 33.7%) and the minimum value is lower.

CONCLUSIONS

Results have important implications for users of the EQ-5D-5L in Slovenia and regions. It is a robust and up-to-date value set and should be the preferred value set used in adults in Slovenia and in neighbouring countries without their own value set.

The EQ-5D-3L Valuation Study in Pakistan

BACKGROUND

To utilize EQ-5D in economic evaluations, a societal-based value set is needed. To date, no value sets exist for any EQ-5D instrument in Pakistan. Previous EQ-5D studies conducted in Pakistan 'borrowed' health preferences developed in other countries. However, for a value set to be valid for Pakistani population, it should represent the preferences of the Pakistani population, and culture and living standards of Pakistan.

OBJECTIVE

The aim of this study was to derive a Pakistani EQ-5D-3L value set.

METHODS

A moderately representative sample aged 18 years and over was recruited from the Pakistani general population. A multi-stage stratified quota method with respect to ethnicity, gender, age and religion was utilized. Two elicitation techniques, the composite time trade-off (cTTO) and discrete choice experiments (DCE) were applied. Interviews were undertaken by trained interviewers using computer-assisted face-to-face interviews with the EuroQol Portable Valuation Technology (EQ-PVT) platform. To estimate the value set, a hybrid regression model combining cTTO and DCE data was used.

RESULTS

A total of 289 respondents who completed the interviews were included for the analysis. The hybrid model correcting for heteroskedasticity without a constant was selected as the final model for the value set. It is shown that being unable to do usual activities (level 3) was assigned the largest weight, followed by mobility level 3, self-care level 3, pain/discomfort level 3 and anxiety/depression level 3. The worst health state was assigned the value - 0.171 in the final model.

CONCLUSIONS

A Pakistani country-specific EQ-5D-3L value set is now available. The availability of this value set may help promote and facilitate health economic evaluations and health-related quality-of-life (HRQoL) research in Pakistan.

UK Valuation of EQ-5D-5L, a Generic Measure of Health-Related Quality of Life: A Study Protocol

OBJECTIVES

A high-quality and widely accepted UK EQ-5D-5L value set is urgently required to enable the latest version of EQ-5D scored using recent UK public preferences to inform policy including health technology assessments submitted to the National Institute for Health and Care Excellence. This article outlines the study protocol for the generation of a new EQ-5D-5L UK value set.

METHODS

Twelve hundred interviews will be undertaken using the composite time trade-off elicitation technique for 102 health states (86 from the international EQ-5D-5L valuation protocol, plus 16 with best predictive performance in an extended design used in the Native American EQ-5D-5L valuation). The sample will be UK adults (age ≥18 years) proportionately representative across England, Wales, Scotland, and Northern Ireland, representative for age, sex, ethnicity, and socioeconomic group, with inclusion of participants with/without health problems. Participants will choose to be interviewed via videoconference (by Zoom) or in-person in a central venue. Data quality will be rigorously assessed.

RESULTS

The value set will be generated using tobit random effects and heteroscedastic tobit models (with censoring at -1) using all data, excluding time trade-off values highlighted by participants as ones they would reconsider and data from interviewers failing protocol compliance. Quality and acceptance will be achieved by public involvement, regular Steering Group meetings, independent assessment of data quality at 4 time points, and final endorsement of data and analyses.

CONCLUSION

This study will produce a UK value set for the EQ-5D-5L for use in prospective and retrospective data sets containing EQ-5D-5L data.

Comparison of the measurement properties of the EQ-5D-5L and SF-6Dv2 among overweight and obesity populations in China

OBJECTIVE

To evaluate and compare the measurement properties of the EQ-5D-5L and SF-6Dv2 among Chinese overweight and obesity populations.

METHODS

A representative sample of Chinese overweight and obesity populations was recruited stratified by age, gender, body mass index (BMI), and area of residence. Social-demographic characteristics and self-reported EQ-5D-5L and SF-6Dv2 responses were collected through the online survey. The agreement was assessed using intraclass correlation coefficients (ICC). Convergent validity and known-group validity were examined using Spearman's rank correlation and effect sizes, respectively. The test-retest reliability was assessed using among a subgroup of the total sample. Sensitivity was compared using relative efficiency and receiver operating characteristic.

RESULTS

A total of 1000 respondents (52.0% male, mean age 51.7 years, 67.7% overweight, 32.3% obesity) were included in this study. A higher ceiling effect was observed in EQ-5D-5L than in SF-6Dv2 (30.6% vs. 2.1%). The mean (SD) utility was 0.851 (0.195) for EQ-5D-5L and 0.734 (0.164) for SF-6Dv2, with the ICC of the total sample was 0.639 (p < 0.001). The Spearman's rank correlation (range: 0.186-0.739) indicated an acceptable convergent validity between the dimensions of EQ-5D-5L and SF-6Dv2. The EQ-5D-5L showed basically equivalent discriminative capacities with the SF-6Dv2 (ES: 0.517-1.885 vs. 0.383-2.329). The ICC between the two tests were 0.939 for EQ-5D-5L and 0.972 for SF-6Dv2 among the subgroup (N = 150). The SF-6Dv2 had 3.7-170.1% higher efficiency than the EQ-5D-5L at detecting differences in self-reported health status, while the EQ-5D-5L was found to be 16.4% more efficient at distinguishing between respondents with diabetes and non-diabetes.

CONCLUSIONS

Both the EQ-5D-5L and SF-6Dv2 showed comparable reliability, validity, and sensitivity when used in Chinese overweight and obesity populations. The two measures may not be interchangeable given the systematic difference in utility values between the EQ-5D-5L and SF-6Dv2. More research is needed to compare the responsiveness.

Valuation of EQ-5D-5L health states from cancer patients' perspective: a feasibility study

OBJECTIVES

To assess the feasibility of estimating an EQ-5D-5L value set using a small study design in cancer patients and to compare the EQ-5D-5L values based on the preferences of cancer patients with those of the general public.

METHODS

Patients with clinically diagnosed cancers were recruited from two hospitals in Shanghai, China. In face-to-face interviews using the EQ-PVT survey, health states were valued by cancer patients using both cTTO and DCE methods. cTTO data was modelled alone or jointly with DCE data. Forty-eight models using different model specifications (cross-attribute level effect [CALE] and additive models), random/fixed effects model assumptions, data heteroscedasticity and censoring were estimated. The best performed model was identified in terms of monotonicity of estimated model coefficients and out-of-sample prediction accuracy.

RESULTS

Data collected from 221 cancer patients who participated in the study were included. The hybrid CALE model using both TTO and DCE data performed best in terms of prediction accuracy (Lin's concordance coefficient = 0.989; root mean squared error = 0.058) and suggested that pain/discomfort and anxiety/depression were the most undesirable health problems. Compared to values based on general Chinese public's health preferences, the values based on cancer patients' preferences were much higher and lower for health states characterized by extreme mobility problems and severe/extreme pain or discomfort, respectively.

CONCLUSION

This study demonstrated the feasibility of using a small design to develop EQ-5D-5L value sets based on cancer patients' health preferences. Since there were signs of differences between preferences of patients and general population, it may be valuable to develop patient-specific value sets and use them in clinical decision making and economic evaluations.

Re-revisiting the Utilities of Health States Worse than Dead: The Problem Remains

BACKGROUND

In valuation studies of the EQ-5D-5L instrument, the composite time tradeoff method (cTTO) is often used to elicit preferences. In cTTO, some health states are considered worse than dead (WTD) and are assigned negative utility values. However, these negative values correlate poorly with state severity, which suggests that cTTO is insufficiently sensitive. A recent threshold explanation has been offered to account for the lack of correlation: because the severity threshold beyond which a state is considered WTD differs between respondents, the correlation should be studied for individual respondents clustered by the number of WTD states. The results obtained in such a threshold approach were interpreted to disprove the insensitivity of the cTTO method.

AIM

To scrutinize the threshold explanation and test whether it indeed refutes the insensitivity of cTTO.

METHODS

The study uses data from the EQ-5D-5L Polish valuation study, which includes cTTO responses from 1,510 participants, each of whom evaluated 10 EQ-5D-5L states. The correlation analysis and threshold approach are repeated to confirm the results from previous studies. The data are then modified in 2 contrasting ways. First, negative utilities are randomly reshuffled to test whether the threshold approach can capture cTTO insensitivity. Second, individual-level regressions are used to simulate negative values to ensure they correlate with severity at the individual respondent level, verifying whether the overall severity-utility correlation should be observed.

RESULTS

First, reshuffling negative utilities does not change the results of the threshold approach. Hence, the threshold explanation fails to prove cTTO sensitivity. Second, when sensitivity was introduced on an individual level, a significant overall correlation between severity and negative utility arose.

CONCLUSION

cTTO is insensitive to severity for WTD states.

HIGHLIGHTS

For the composite time tradeoff method, the utility values of health states worse than dead correlate poorly with state severity, which suggests that cTTO has insufficient sensitivity.Recently, a so-called threshold explanation was offered for the lack of correlation.I show why the threshold explanation fails and why the composite time tradeoff is indeed insensitive for worse-than-dead states.

Valuing Chinese medicine quality of life-11 dimensions (CQ-11D) health states using a discrete choice experiment with survival duration (DCETTO)

OBJECTIVE

To explore generating a health utility value set for the Chinese medicine Quality of life-11 Dimensions (CQ-11D), a utility instrument designed to assess patients' health status while receiving TCM treatment, among the Chinese population.

METHODS

The study was designed to recruit at least 2400 respondents across mainland China to complete one-to-one, face-to-face interviews. Respondents completed ten discrete choice experiment with survival duration (DCETTO) tasks during interviews. The conditional logit models were used to generate the health utility value set for the CQ-11D using the DCETTO data.

RESULTS

A total of 2,586 respondents were invited to participate in the survey and 2498 valid interviews were completed (a completion rate of 96.60%). The modified conditional logit model with combing logically inconsistent levels was ultimately selected to construct the health utility value set for the CQ-11D instrument. The range of the measurable health utility value was -0.868 ~ 1.

CONCLUSION

The study provides the first utility value set for the CQ-11D among the Chinese population. The CQ-11D and corresponding utility value set can be used to measure the health utility values of patients undergoing traditional Chinese medicine interventions, and further facilitate relevant cost-utility analyses. The application of the CQ-11D can support TCM resource allocation in China.

Comparison of Preferences and Data Quality between Discrete Choice Experiments Conducted in Online and Face-to-Face Respondents

INTRODUCTION

Discrete choice experiments (DCE) are increasingly being conducted using online panels. However, the comparability of such DCE-based preferences to traditional modes of data collection (e.g., in-person) is not well established. In this study, supervised, face-to-face DCE was compared with its unsupervised, online facsimile on face validity, respondent behavior, and modeled preferences.

METHODS

Data from face-to-face and online EQ-5D-5L health state valuation studies were compared, in which each used the same experimental design and quota sampling procedure. Respondents completed 7 binary DCE tasks comparing 2 EQ-5D-5L health states presented side by side (health states A and B). Data face validity was assessed by comparing preference patterns as a function of the severity difference between 2 health states within a task. The prevalence of potentially suspicious choice patterns (i.e., all As, all Bs, and alternating As/Bs) was compared between studies. Preference data were modeled using multinomial logit regression and compared based on dimensional contribution to overall scale and importance ranking of dimension-levels.

RESULTS

One thousand five Online respondents and 1,099 face-to-face screened (F2FS) respondents were included in the main comparison of DCE tasks. Online respondents reported more problems on all EQ-5D dimensions except for Mobility. The face validity of the data was similar between comparators. Online respondents had a greater prevalence of potentially suspicious DCE choice patterns ([Online]: 5.3% [F2FS] 2.9%, P = 0.005). When modeled, the relative contribution of each EQ-5D dimension differed between modes of administration. Online respondents weighed Mobility more importantly and Anxiety/Depression less importantly.

DISCUSSION

Although assessments of face validity were similar between Online and F2FS, modeled preferences differed. Future analyses are needed to clarify whether differences are attributable to preference or data quality variation between modes of data collection.

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.

Resective Epilepsy Surgery, QUality of life and Economic evaluation (RESQUE): the change in quality of life after resective epilepsy surgery-protocol for a multicentre, prospective cohort study

INTRODUCTION

Resective epilepsy surgery is often seen as a last resort when treating drug-resistant epilepsy. Positive results on quality of life (QoL) and economic benefits after surgery argue for a less restrictive attitude towards epilepsy surgery for drug-resistant epilepsy. QoL and economic benefits are country-dependent. The objective of the Resective Epilepsy Surgery, QUality of life and Economic evaluation (RESQUE) trial is to evaluate the change in QoL before and after epilepsy surgery in Dutch people with drug-resistant epilepsy. The results will form part of an economic evaluation of epilepsy surgery in people with epilepsy (PWE) in The Netherlands.

METHODS AND ANALYSIS

A longitudinal prospective multicentre cohort study involving 100 PWE undergoing epilepsy surgery between 2019 and 2025 is being performed in three Dutch academic hospitals. Excluded are PWE who have a lower level of intelligence (TIQ<70) or who do not master the Dutch language. Before surgery and 3, 6, 12 and 24 months after surgery, PWE receive validated online questionnaires (QOLIE-31, EQ-5D, iMCQ and iPCQ) on QoL, cost of care, expectations and satisfaction. Primary outcome is the change in QoL. Secondary outcomes are change in generic QoL, seizure reduction (International League Against Epilepsy Outcome Classification), medical consumption, productivity, the correlation between QoL and seizure reduction and expectation of and satisfaction with the surgery.

ETHICS AND DISSEMINATION

The study design has been approved by the Medical Ethics Review Committee (METC) of Maastricht UMC+ (2019-1134) and the Amsterdam UMC (vu). At the time of writing, UMC Utrecht is in the process of considering approval. The study will be conducted according to the Dutch Medical Research Involving Human Subjects Act and the Declaration of Helsinki. The results will be publicly disclosed and submitted for publication in international peer-reviewed scientific journals. There is no veto on publication by the involved parties.

TRIAL REGISTRATION

NL8278; Pre-results.

Using Time Trade-Off Values to Estimate EQ-5D-Y Value Sets: An Exploratory Study

OBJECTIVES

The published international EQ-5D-Y-3L valuation protocol does not recommend the composite time trade-off (cTTO) method as the primary valuation method because of 2 major concerns. First, the cTTO method was shown to generate high values. Second, the cTTO method is not as feasible for valuing children's health as other established methods. This study aimed to explore the feasibility of using cTTO values alone to estimate EQ-5D-Y-3L value sets.

METHODS

We analyzed the cTTO data derived from the recently completed Chinese EQ-5D-Y-3L valuation study in which a total of 28 health states were valued. We assessed the feasibility of the cTTO tasks in terms of survey completion time and participant-reported difficulty of understanding the task, differentiating the health states, and deciding the answer. We also examined the data distribution characteristics and modeled the data using different models.

RESULTS

In total, 418 participants completed the cTTO interview. On average, participants took approximately 35.70 minutes (SD 12.42) to complete the interview and made 13.21 moves (SD 9.00) in the cTTO tasks. There were 74.16%, 59.33%, and 11.48% of participants indicated that it was easy to understand the cTTO tasks, easy to differentiate between the health states, and difficult to decide on an indifference point, respectively. The data distribution was smooth, and a random-effects model performed the best in terms of coefficient significance, monotonicity, and predictive accuracy.

CONCLUSION

Our finding suggests that estimating EQ-5D-Y-3L value sets using cTTO data alone is feasible and therefore could be considered as an option in future valuation studies for EQ-5D-Y-3L.

Cross-Attribute Level Effects Models for Modeling Modified 5-Level Version of EQ-5D Health State Values: Is Less Still More?

OBJECTIVES

Cross-attribute level effects (CALE) model has demonstrated better predictive accuracy for out-of-sample health states than the conventional additive main-effects model in cross-validation analysis of the 5-level version of EQ-5D (EQ-5D-5L) composite time trade-off (cTTO) datasets. In this study, we aimed to further test the performance of CALE model using a different design and modified EQ-5D-5L states.

METHODS

A total of 29 EQ-5D-5L self-care bolt-off states, 30 EQ-5D-5L states, and 31 EQ-5D-5L vision bolt-on states were selected from the same orthogonal array. A total of 600 university students were interviewed face-to-face to value a subset of these health states using the cTTO method. For each type of health state, we fitted both the conventional main-effects model and the CALE model. Predictive accuracy was assessed in a series of cross-validation analysis using the leave-one-state-out method.

RESULTS

Overall, the CALE model outperformed the conventional model for each of the 3 types of health states in predicting the cTTO values of out-of-sample health states. The prediction accuracy of using the CALE model improved with the number of dimensions in health states, for example, the MAE decreased about 24%, 67%, and 77% for the EQ-5D-5L self-care bolt-off, EQ-5D-5L, and EQ-5D-5L vision bolt-on states, respectively, when using CALE models.

CONCLUSION

Our study supported the strengths of the CALE model for modelling the utility values of both original and modified EQ-5D-5L health states. Investigators with limited resources may consider using the CALE model to lower the costs for their valuation studies for EQ-5D-5L or similar health state descriptive systems.

Censoring Time Trade-off Values at 0 Versus at -1: How Does the Assumption for Worse-Than-Dead Time Trade-off Values Affect the Modeling of EQ-5D-5L Valuation Data?

OBJECTIVES

A recent study found that negative utility values elicited using composite time trade-off (TTO) were barely associated with the severity of EQ-5D-5L health states, suggesting poor discriminative ability. Assuming negative values provide limited information, this study aimed to explore the usefulness of censoring negative TTO values at 0 in modeling EQ-5D-5L valuation data.

METHODS

We analyzed EQ-5D-5L valuation data from China, The Netherlands, Canada, Singapore, and Thailand. For each data set, we estimated value sets using 2 Tobit models, one left-censored at -1 (current practice) and one left-censored at 0 (our proposed method), and compared the model performances. We hypothesized that censoring at 0 and censoring at -1 would produce similar values, though on slightly different scales.

RESULTS

When censoring at 0, logical inconsistencies and statistical significance were improved but the value range was compressed. In the cross-attribute level effects model, the 3-level parameters were similar between the models censored at 0 and -1, but the rank order of some dimension parameters was altered. Health state values predicted by the 2 censoring models approximated a perfect agreement after rescaling.

CONCLUSIONS

Censoring TTO values at 0 improved model estimation and fit but produced higher utility values than models censoring at -1. Investigators of future EQ-5D value set studies using the composite TTO method are advised to examine the validity of negative TTO values before choosing modeling strategies.

Efficient Designs for Valuation Studies That Use Time Tradeoff (TTO) Tasks to Map Latent Utilities from Discrete Choice Experiments to the Interval Scale: Selection of Health States for TTO Tasks

BACKGROUND

In eliciting utilities to value multiattribute utility instruments, discrete choice experiments (DCEs) administered online are less costly than interviewer-facilitated time tradeoff (TTO) tasks. DCEs capture utilities on a latent scale and are often coupled with a small number of TTO tasks to anchor utilities to the interval scale. Given the costly nature of TTO data, design strategies that maximize value set precision per TTO response are critical.

METHODS

Under simplifying assumptions, we expressed the mean square prediction error (MSE) of the final value set as a function of the number J of TTO-valued health states and the variance VJ of the states' latent utilities. We hypothesized that even when these assumptions do not hold, the MSE 1) decreases as VJ increases while holding J fixed and 2) decreases as J increases while holding VJ fixed. We used simulation to examine whether there was empirical support for our hypotheses a) assuming an underlying linear relationship between TTO and DCE utilities and b) using published results from the Dutch, US, and Indonesian EQ-5D-5L valuation studies.

RESULTS

Simulation set (a) supported the hypotheses, as did simulations parameterized using valuation data from Indonesia, which showed a linear relationship between TTO and DCE utilities. The US and Dutch valuation data showed nonlinear relationships between TTO and DCE utilities and did not support the hypotheses. Specifically, for fixed J, smaller values of VJ reduced rather than increased the MSE.

CONCLUSIONS

Given that, in practice, the underlying relationship between TTO and DCE utilities may be nonlinear, health states for TTO valuation should be placed evenly across the latent utility scale to avoid systematic bias in some regions of the scale.

HIGHLIGHTS

Valuation studies may feature a large number of respondents completing discrete choice tasks online, with a smaller number of respondents completing time tradeoff (TTO) tasks to anchor the discrete choice utilities to an interval scale.We show that having each TTO respondent complete multiple tasks rather than a single task improves value set precision.Keeping the total number of TTO respondents and the number of tasks per respondent fixed, having 20 health states directly valued through TTO leads to better predictive precision than valuing 10 health states directly.If DCE latent utilities and TTO utilities follow a perfect linear relationship, choosing the TTO states to be valued by weighting on the 2 ends of the latent utility scale leads to better predictive precision than choosing states evenly across the latent utility scale.Conversely, if DCE latent utilities and TTO utilities do not follow a linear relationship, choosing the states to be valued using TTO evenly across the latent utility scale leads to better predictive precision than weighted selection does.In the context of valuation of the EQ-5D-Y-3L, we recommend valuing 20 or more health states using TTO and placing them evenly across the latent utility scale.

EQ-5D-5L: a value set for Romania

OBJECTIVE

We aimed to develop an EQ-5D-5L value set for Romania.

METHODS

In line with the EuroQoL standardized valuation protocol, computer-assisted interviews were conducted face-to-face in a representative sample in Romania (November 2018-November 2019). Valuation methods included composite time trade-off and discrete choice experiment tasks. Several models were tested, including models that accounted for data censoring, panel structure of the data, heteroscedasticity, conditional logit, and hybrid models. The final model was selected based on logical consistency, theoretical considerations, and use of all available data. We compared our value set with other value sets from Central and Eastern Europe region.

RESULTS

Data from 1493 respondents was used to estimate the value set. A censored hybrid model corrected for heteroscedasticity was selected to represent the value set. The highest decrements in utility were observed for the pain/discomfort dimension (0.375), followed by the mobility dimension (0.293). Health utilities ranged from 1.000 to - 0.323 and 1.3% of the values were negative. The model was corrected with survey weights to better reflect the representativeness of the sample, but the first two coefficients of the self-care dimension stopped being logically consistent. Differences were found between the Romanian, Hungarian and Polish EQ-5D-5L value sets. Good agreement was noted with the Romanian EQ-5D-3L value set, with a swap between pain/discomfort and mobility in ranking of dimensions.

CONCLUSION

A value set for EQ-5D-5L is now available for Romania. This will push one-step further the development of health technology assessment and encourage more health-related quality-of-life research to be conducted locally.

Urban/rural differences in preferences for EQ-5D-5L health states: a study of a multi-ethnic region in China

OBJECTIVES

This study aimed to compare health preferences for EQ-5D-5L health states between urban and rural populations in China.

METHODS

This study used pooled secondary data from two EQ-5D-5L valuation studies. Participants were recruited from Guizhou province and Chongqing municipality, China using quota sampling. Each participant was interviewed face-to-face to value a set of 15 or 16 out of 30 EQ-5D-5L health states using time trade-off (TTO) methods including composite TTO and other two variants. Regression analysis was used to compare health state preferences between urban and rural participants.

RESULTS

A total of 597 participants (urban: 55.44%; rural: 44.56%) completed the valuation interviews. Both univariate and multivariable linear regression analyses showed that rural participants tended to value health states lower than urban participants regardless of severity of health states. The unadjusted and adjusted overall mean differences between the two groups were - 0.041 (95% confidence interval [CI] - 0.077, - 0.004, p-value = 0.031) and - 0.040 (95% CI - 0.078, - 0.002, p-value = 0.038), respectively. Predictions for the 3125 health states based on rural participants' health preferences were lower than those based on urban participants' health preferences.

CONCLUSION

There were small, yet statistically significant, differences in EQ-5D-5L health states preferences between urban and rural populations in China. Future study aiming at establishing a national value set should pay more attention to the sample representativeness.

Health state utility estimation of Mycobacterium Avium complex pulmonary disease using a time trade-off approach

AIMS

To obtain appropriate health state utility values for cost-effectiveness analyses of new Mycobacterium avium complex pulmonary disease (MAC-PD) treatments. The impact of MAC-PD severity and symptoms on quality of life (QoL) also were quantified.

METHODS

A questionnaire describing four health states, MAC-positive severe, MAC-positive moderate, MAC-positive mild, and MAC-negative, was developed based on St. George's Respiratory Questionnaire (SGRQ) Symptom and Activity scores from the CONVERT trial. The time trade-off (TTO) method with ping-pong titration procedure was used to estimated health state utilities. Regression analyses assessed impacts of covariates.

RESULTS

Of 319 Japanese adults (49.8% female, mean age 44.8 years), mean (95% CI) health state utility scores (MAC-positive severe, MAC-positive moderate, MAC-positive mild, and MAC-negative) were 0.252 (0.194-0.310), 0.535 (0.488-0.582), 0.816 (0.793-0.839), and 0.881 (0.866-0.896), respectively. MAC-negative state utility scores were significantly higher than MAC-positive severe (mean difference [95% CI], 0.629 [0.574-0.684]), MAC-positive moderate (0.346 [0.304-0.389]), and MAC-positive mild (0.065 [0.048-0.082]) scores (p < 0.001 each). Most participants would trade survival duration to avoid MAC-positive states (97.5% to avoid MAC-positive severe; 88.7% MAC-positive moderate; 61.4% MAC-positive mild). Regression analyses to investigate the impact of background characteristics showed similar utility differences between health states when not adjusted for covariates.

LIMITATIONS

Some participant demographics differed from the general population; however, this did not impact utility differences among health states as regression analyses adjusting for demographics did not affect these differences. Similar investigations are needed among patients with MAC-PD and in other countries.

CONCLUSIONS

This study evaluating the impact of MAC-PD on utilities using the TTO method demonstrates that differences in utilities are dependent on the severity of respiratory symptoms and their impacts on daily activities and QoL. These results could contribute to better quantification of the value of MAC-PD treatments and improve assessments of cost-effectiveness.

A national survey of Iranian general population to estimate a value set for the EQ-5D-5L

OBJECTIVES

The main aim of this study is to estimate a national value set of the EQ-5D-5L questionnaire for Iran.

METHODS

The composite time trade-off (cTTO) and discrete choice experiment (DCE) methods; and the protocol for EuroQol Portable Valuation Technology (EQ-PVT) were used to estimate the Iran national value set. 1179 face-to-face computer-assisted interviews were conducted with adults that were recruited from five Iran major cities in 2021. Generalized least squares, Tobit, heteroskedastic, logit, and hybrid models were used to analyze the data and to identify the best fitting model.

RESULTS

According to the logical consistency of the parameters, significance levels and prediction accuracy indices of the MAE; a heteroscedastic censored Tobit hybrid model combining cTTO and DCE responses was considered as the best fitting model to estimate the final value set. The predicted values ranged from - 1.19 for the worst health state (55555) to 1 for full health (11111), with 53.6% of the predicted values being negative. Mobility was the most influential dimension on health state preference values.

CONCLUSIONS

The present study estimated a national EQ-5D-5L value set for Iranian policy makers and researchers. The value set enables the EQ-5D-5L questionnaire to use to calculate QALYs to assist the priority setting and efficient allocation of limited healthcare resources.

Randomised comparison of online interviews versus face-to-face interviews to value health states

INTRODUCTION

Health state valuation studies using composite time trade-off (cTTO) interviews have historically been conducted face-to-face. The COVID-19 pandemic forced disruptive innovation meaning a number of valuation studies conducted interviews via videoconference. These studies found online interviews feasible and acceptable; however, studies were not constructed to test the impact of online versus face-to-face interviews. This study builds on its sister study from the UK and aims to assess the acceptability and equivalence of in person face-to-face interviews with online interviews on cTTO valuation outcomes and on data quality.

METHODS

Participants were recruited into a randomised equivalence study via an external research company. Consenting participants were randomly allocated to complete a cTTO interview face-to-face or online, using the same 10 EQ-5D-5L health states. Mean and distribution of the cTTO values, participant understanding, data quality, demographic characteristics, participant preference, participant engagement and participant feedback were all compared across interview mode. Statistical equivalence for cTTO values for each state was tested using two one-sided t-tests by mode. Finally, regression analysis was completed to assess the impacts of interview mode on cTTO value while controlling for demographic characteristics of the participants.

RESULTS

Mean cTTO values were shown to be equivalent for mild health states and showed no significant difference for serious health states. The proportion of individuals who expressed an interest in the study but declined to arrange an interview after finding out their randomisation was significantly higher for the face-to-face (21.6%) than the online group (1.8%). No significant difference was found between groups for participant engagement, understanding or feedback nor for any indicators of data quality.

CONCLUSION

Administrating interviews face to face or online did not appear to have a statistically significant impact on mean cTTO values. Offering both online and face-to-face interviews routinely allows all participants to select the most convenient option.

EQ-5D-5L Population Norms for Italy

OBJECTIVES

This study aimed to provide normative data obtained in response to the EQ-5D-5L questionnaire in Italy and compare this with data from other countries.

METHODS

A sample of the Italian adult population (aged ≥ 18 years) was recruited and interviewed online using videoconferencing software (Zoom) between November 2020 and February 2021. The distribution of answers was estimated as per the descriptive system of the EQ-5D-5L, and descriptive statistics were calculated for the EQ VAS score and EQ-5D-5L index value in the whole sample and relevant subgroups. An ordinary least square (OLS) regression was performed to evaluate the impact of sociodemographic variables on EQ-5D-5L results. Lastly, a comparison was made with EQ-5D-5L population norms of other countries. Data analysis was performed using Microsoft Excel and Stata 13.

RESULTS

Overall, 1182 people representative of the Italian population (2020) in terms of sex and geographical area responded to the survey. Of the 3125 potential EQ-5D-5L health states, only 106 (3.4%) were selected, and the '11111' and '11112' states were chosen by half of the participants. In terms of EQ-5D-5L dimensions, the frequency of any problems (from slight to extreme) associated with anxiety and depression was high among the very young (18-24 years, 56.0%) and in women of all ages (49.7%). The mean index value (± standard deviation [SD]) was 0.93 (± 0.11) for the entire sample and gradually decreased with age, moving from 0.95 (± 0.06) in the youngest group (18-24 years) to 0.91 (± 0.13) in the oldest age group (≥ 75 years). Similarly, the mean EQ VAS score (± SD) was 81.8 (± 13.5), and decreased from 87.0 (± 8.9) in the 18-24 years age group to 75.1 (± 16.4) among participants > 75 years of age. The existence of self-reported chronic conditions (e.g., cardiovascular disease), female sex, and social assistance recipiency were negatively associated with the EQ-5D index value, while the EQ VAS score was significantly lower in people with chronic conditions and aged > 55 years. Conversely, higher income levels had a positive impact on both the EQ-5D index value and the EQ VAS score. Lastly, both the EQ-5D index value and EQ VAS score in Italy were, on average, higher than in most European countries.

CONCLUSIONS

EQ-5D-5L population norms provide useful insights into the health status of the Italian population and can be used as a reference for other surveys using the same instrument.

The Egyptian EQ-5D-5L Extensive Pilot Study: Lessons Learned

OBJECTIVES

To investigate the effect of an extensive pilot phase in improving protocol compliance, face validity, reduction of interviewer effect and prediction errors in the composite time trade-off (cTTO) data elicited as part of the EQ-5D-5L valuation study in Egypt.

METHODS

This study used the cTTO data and quality control (QC) reports from the Egyptian EQ-5D-5L valuation study. Three-level mixed models were estimated to test whether interviewer effects were reduced during the pilot phase and subsequent rounds of collected cTTO data. Ordinary least square (OLS) regression analysis was conducted for each interviewer separately to test whether the mean absolute error (MAE) improved as interviewers completed more interviews. Moreover, improvement in protocol compliance, face validity and reduction of prediction errors in the cTTO data were tested.

RESULTS

1180 interviews were conducted by nine interviewers and included in the final analysis, of which 206 interviews were pilot and 974 interviews were actual. There was substantial improvement in the face validity and reduction of prediction errors in the cTTO data where the MAE of the actual data was 0.37, which is much lower than that of the pilot data, which was 0.44. However, there was an initial high level of protocol compliance in terms of the four indicators of the QC tool and the variance attributed to the interviewers was small throughout the whole study.

CONCLUSIONS

This study clarified the benefits of the pilot phase and the strict implementation of the QC tool in improving the face validity and the prediction accuracy of the cTTO data. However, a more extensive pilot phase may be more beneficial in EQ-5D-5L valuation studies that have issues initially with protocol compliance and interviewer effects.

Health-related quality of life among Indian population: The EQ-5D population norms for India

Background

The EuroQol 5 dimensions (EQ-5D) is the most used generic health-related quality of life (HRQoL) instrument for measuring population health and health outcomes. Since there are no EuroQol 5 dimensions 5 levels (EQ-5D-5L) population norms available for India, this study developed the Indian population norms for the EQ-5D-5L. The potential influencing factors of HRQoL of the Indian population have been identified.

Methods

The data was collected alongside the Indian EQ-5D-5L valuation study (Development of an EQ-5D Value Set for India Using an Extended Design: DEVINE Study). A cross-sectional survey of 3548 adult respondents was conducted across five states of India, in which respondents were asked to report their own health states using the EQ-5D-5L descriptive system and the EuroQol Visual Analog Scale (EQ VAS). The utility score was calculated using the EQ-5D-5L value set based on the preferences of the Indian population. Norm scores were generated for age, sex, and other important socio-demographic variables. The proportion of patients reporting problems in different dimensions of EQ-5D-5L was assessed. The impact of socio-economic determinants on health-related quality of life was evaluated using multiple linear regression.

Results

The mean EQ VAS score of the Indian population is 75.18 (95% confidence interval (CI) = 74.50-75.90), whereas mean utility score is 0.848 (95% CI = 0.840-0.857). The EQ VAS scores, and utility scores decreased with age. Males reported higher EQ VAS values than females. The highest mean utility score was observed for males of <20 years (0.936), whereas the lowest mean score was observed for females of >70 years (0.488). The mean VAS score ranged between 85.24 for females of <20 years and 50.67 for females of >70 years. Highest problems were reported in the dimension of "pain / discomfort", closely followed by "anxiety / depression". Age, educational qualification, marital status, substance abuse, presence of ailments, state / region of residence, number of dependent members in the household, and time spent on mobile are the significant determinants of HRQoL of Indian population.

Conclusions

These population norms will be used as reference values for comparative purposes in future Indian studies. Economic evaluations can use these average age-specific HRQoL population norms to value the health-state of not having the specific disease under investigation.

Health state utilities for beta-thalassemia: a time trade-off study

BACKGROUND

Beta-thalassemia (BT) is an inherited blood disorder characterized by reduced levels of functional hemoglobin resulting in phenotypes ranging from clinically asymptomatic to severely anemic. Patients with BT may require lifelong regular blood transfusions supported by appropriate iron chelation therapy (ICT). This study aimed to determine how the UK general population values BT health states associated with differing transfusion burden and ICT.

METHODS

Composite time trade-off (cTTO) methodology was employed to elicit health state utilities in BT. Relevant BT literature related to symptom and quality-of-life impact, including physical, functional, and emotional well-being, and safety profiles of BT treatments were considered when drafting health state descriptions. Eleven health state descriptions were developed and validated by hematologists and patient advocates for clinical accuracy and completeness. 200 individuals from the UK general population participated in the cTTO interviews.

RESULTS

The mean age of participants was 41.50 years (SD 16.01, range 18-81); 88 (46.8%) were female. Utility values ranged from 0.78 (SD 0.34) for non-transfusion dependent BT with oral ICT to 0.37 (SD 0.50) for high transfusion burden with subcutaneous ICT in transfusion-dependent BT.

CONCLUSIONS

This study provides health utilities for a range of BT health states from the UK general population perspective. Importantly, lower transfusion burden and lower burden of anemia were associated with higher utilities. To a lesser extent, differential modes of ICT were found to impact utility valuations in patients with BT. The utilities obtained in this study can be employed as inputs in cost-effectiveness analyses of BT therapies.

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

OBJECTIVES

In cost-effectiveness analysis of health technologies, health state utilities are needed. They are often elicited with a composite time trade-off (cTTO) method, particularly for the widely used EQ-5D-5L. Unfortunately, cTTO discriminatory power is hindered by (1) respondents' nontrading (NT) of time for quality, (2) censoring of utilities at -1, and (3) poor correlation of negative utilities with state severity. We investigated whether modifying cTTO can mitigate these effects.

METHODS

We interviewed online 478 students (February to April, 2021) who each valued the same 10 EQ-5D-5L health states in 1 of 3 arms. Arm A used a standard cTTO, expanded with 2 questions to explore reasons for NT and censoring. Arms B and C used a time trade-off with modified alternatives offered to overcome loss aversion, to unify the tasks for positive and negative utilities, and to enable eliciting utilities < -1.

RESULTS

In arms B and C, we observed less NT than in A (respectively, 4% and 4% vs 10%), more strictly negative utilities (38% and 40% vs 25%), and more utilities ≤ -1 (18% and 30% vs 10%). The average utility of state 55555 dropped to -2.15 and -2.52 from -0.53. Enabling finer trades in arm A reduced NT by 70%. Arms B and C yielded an intuitive association between negative utilities and state severity. These arms were considered more difficult and resulted in more inconsistencies.

CONCLUSIONS

The discriminatory power of cTTO can be improved, but it may require increasing the difficulty of the task. The standard cTTO may overestimate the utilities, especially of severe states.

Estimating an EQ-5D-Y-3L Value Set for Indonesia by Mapping the DCE onto TTO Values

BACKGROUND AND OBJECTIVES

Methods for estimating health values in adult populations are well developed, but lag behind in children. The EuroQol standard protocol to arrive at value sets for the youth version of the EQ-5D-Y-3L combines discrete choice experiments with ten composite time trade-off values. Whether ten composite time trade-off values are sufficient remains to be seen and this is one of the reasons the protocol allows for experimental expansion. In this study, 23 health states were administered for the composite time trade-off. This methodological research is embedded in a study aimed at generating a representative value set for EQ-5D-Y-3L in Indonesia.

METHODS

A representative sample of 1072 Indonesian adults each completed 15 discrete choice experiment choice pairs via face-to-face interviews. The discrete choice experiment responses were analysed using a mixed-logit model. To anchor the discrete choice experiment values onto the full health-dead quality-adjusted life-year scale, composite time trade-off values were separately obtained from 222 adults living in Java for 23 EQ-5D-Y-3L states. The derived latent discrete choice experiment values were mapped onto the mean observed composite time trade-off values to create a value set for the EQ-5D-Y-3L. Linear and non-linear mapping models were explored to estimate the most efficient and valid model for the value set.

RESULTS

Coefficients obtained from the choice model were consistent with the monotonic structure of the EQ-5D-Y-3L instrument. The composite time trade-off data showed non-linearity, as the values for the two worst states being evaluated were much lower than predicted by a standard linear model estimated over all composite time trade-off data. Thus, the non-linear mapping strategies with a power term outperformed the linear mapping in terms of mean absolute error. The final model gave a value range from 1.000 for full health (11111) to - 0.086 for the worst health state (33333). Values were most affected by pain/discomfort and least by self-care.

CONCLUSIONS

This article presents the first EQ-5D-Y-3L value set for Indonesia based on the stated preferences of adults asked to consider their views about a 10-year-old child. Mapping the mixed-logit discrete choice experiment model with the inclusion of a power term (without a constant) allowed us to generate a consistent value set for Indonesian youth. Our findings support the expansion of the composite time trade-off part of the EQ-5D-Y valuation study design and show that it would be wise to account for possible non-linearities in updates of the design.

Conceptual Framework for Optimised Proxy Value Set Selection Through Supra-National Value Set Development for the EQ-5D Instruments

BACKGROUND

Preference differences between countries and populations justify the use of country-specific value sets for the EQ-5D instruments. There are no clear criteria based on which the selection of value sets for countries without a national value set should be made. As part of the European PECUNIA project, this study aimed to identify factors contributing to differences in preference-based valuations and develop supra-national value sets for homogenous country clusters in Europe.

METHODS

A literature review was conducted to identify factors relevant to variations in the EQ-5D-3L/5L health state valuations across countries. Factors fulfilling the pre-specified criteria of validity, reliability, international feasibility and comparability were used to group 27 European Union member states, the European Free Trade Association countries and the UK. Clusters of countries were developed based on the frequency of their appearance in the same grouping. The supra-national value sets were estimated for these clusters from the coefficients of existing published valuation studies using the ordinary least-squares model.

RESULTS

Ten factors were identified from 69 studies. From these, five grouping variables: (1) culture and religion; (2) linguistics; (3) healthcare system typology; (4) healthcare system financing; and (5) sociodemographic aspects were derived to define the groups of homogenous countries. Frequency-based grouping revealed five cohesive clusters: English-speaking, Nordic, Central-Western, Southern and Eastern European.

CONCLUSIONS

European countries were clustered considering variables that may relate to differences in health state valuations. Supra-national value sets provide optimised proxy value set selection in the lack of a national value set and/or for regional decision making.

A Value Set for the EQ-5D-Y-3L in the Netherlands

BACKGROUND AND OBJECTIVE

There is increasing interest in preference-accompanied measures of health for paediatric populations. The child-friendly EQ-5D version, EQ-5D-Y-3L, is one such instrument, but the lack of a Dutch value set prevents its use in economic evaluations of healthcare interventions in the Netherlands. This study aims at covering this gap by collecting preferences using a standardised protocol for deriving EQ-5D-Y-3L value sets.

METHODS

Composite time trade-off data were collected using videoconferencing interviews, with each respondent completing ten composite time trade-off tasks. Discrete choice experiment data were collected using an online survey, with respondents each completing 15 paired comparisons. Respondents completed these tasks considering what they prefer for a hypothetical 10-year-old child. Discrete choice experiment data were analysed using a ten-parameter mixed-logit model and anchored to the quality-adjusted life-year scale using the mean observed composite time trade-off values.

RESULTS

The study collected preferences for 197 respondents using composite time trade-off and for 959 respondents using a discrete choice experiment. The discrete choice experiment sample was representative for the Dutch population in terms of age and sex. The level 3 weight for pain/discomfort was the largest, followed by feeling worried, sad or unhappy, usual activities, mobility and self-care. Health state values ranged between -0.218 and 1.

CONCLUSIONS

This study generated a Dutch value set for the EQ-5D-Y-3L, which can be used for the computation of quality-adjusted life-years for economic evaluations of healthcare interventions in paediatric populations.

An EQ-5D-Y-3L Value Set for Belgium

BACKGROUND

In Belgium, a value set for children and adolescents for a generic health-related quality-of-life measure is not available. To inform drug pricing and make resource allocation decisions for children and adolescents, national tax-payers' preferences for youth health states should be known.

OBJECTIVE

We aimed to obtain a value set for EQ-5D-Y-3L in Belgium, following the international youth valuation protocol for data collection.

METHODS

Composite Time Trade-Off interviews were conducted in a sample of 200 adults, either face to face or via video conferencing. Another sample of 1000 adults completed an online discrete choice experiment survey. All adults were asked to take the perspective of a 10-year-old child for both methods. Both samples were representative for Belgium in terms of age, sex and region. A latent class analysis was selected to obtain the relative importance of the five dimensions and their levels based on the discrete choice experiment data, which were anchored with the composite Time Trade-Off censored value for the worst health state (33333).

RESULTS

Preferences from Belgian adults revealed a mean censored value for 33333 for children and adolescents of - 0.475. All the estimated coefficients of the model with 4 latent classes were statistically significant and showed higher disutility as severity levels increase. The most important health dimension was pain/discomfort, followed by feeling sad/worried/unhappy.

CONCLUSIONS

This study presents the Belgian EQ-5D-Y-3L value set, which will be included in the Belgian pharmacoeconomic guidelines. The value set enables the calculation of quality-adjusted life-years in children and adolescents, allowing a cost-effectiveness evaluation of health technologies and their youth-specific price setting.

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

BACKGROUND AND OBJECTIVES

EQ-5D-Y-3L health states are commonly valued by asking adults to complete stated preference tasks, 'given their views about a 10-year-old child' (hereafter referred to as proxy 1). The use of this perspective has been a source of debate. In this paper, we investigated an alternative proxy perspective: i.e. adults considered what they think a 10-year old-child would decide for itself (hereafter, proxy 2 (substitute)]. Our main objective was to explore how the outcomes, dispersion and response patterns of a composite time trade-off valuation differ between proxy 1 and proxy 2.

METHODS

A team of four trained interviewers completed 402 composite time trade-off interviews following the EQ-5D-Y-3L protocol. Respondents were randomly allocated to value health states in either the proxy 1 or proxy 2 (substitute) perspective. Each respondent valued ten health states with the perspective they were assigned to, as well as one health state with the alternative perspective (33333).

RESULTS

The use of different proxy perspectives yielded differences in EQ-5D-Y-3L valuation. For states in which children had considerable pain and were very worried, sad or unhappy, respondents' valuations were lower in proxy 1 than in proxy 2 (substitute) perspectives, by about 0.2. Within-subject variation across health states was lower for proxy 2 (substitute) than proxy 1 perspectives. Analyses of response patterns suggest that data for proxy 2 (substitute) perspectives were less clustered.

CONCLUSIONS

There are systematic differences between composite time trade-off responses given by adults deciding for children and adults considering what children would want for themselves. In addition to warranting further qualitative exploration, such differences contribute to the ongoing normative discussion surrounding the source and perspective used for valuation of child and adolescent health.

Value Set for the EQ-5D-Y-3L in Hungary

BACKGROUND

The Hungarian health technology assessment guidelines recommend the use of the EuroQol instrument family in quality-adjusted life-year calculations. However, no national value set exists for the EQ-5D-Y-3L or any other youth-specific instrument.

OBJECTIVE

This study aims to develop a national value set of the EQ-5D-Y-3L for Hungary based on preferences of the general adult population.

METHODS

This study followed the international valuation protocol for the EQ-5D-Y-3L. Two independent samples, representative of the Hungarian general adult population in terms of age and sex were recruited to complete online discrete choice experiment (DCE) tasks and composite time trade-off (cTTO) tasks by computer-assisted personal interviews. Adults valued hypothetical EQ-5D-Y-3L health states considering the health of a 10-year-old child. DCE data were modelled using a mixed logit model with random-correlated coefficients. Latent DCE utility estimates were mapped onto mean observed cTTO utilities using ordinary least squares regression.

RESULTS

Overall, 996 and 200 respondents completed the DCE and cTTO surveys, respectively. For each domain, the value set resulted in larger utility decrements with more severe response levels. The relative importance of domains by level 3 coefficients was as follows: having pain or discomfort > feeling worried, sad or unhappy > mobility > doing usual activities > looking after myself. Overall, 12.3% of all health states had negative utilities in the value set, with the worst health state having the lowest predicted utility of - 0.485.

CONCLUSION

This study developed a national value set of the EQ-5D-Y-3L for Hungary. The value set enables to evaluate the cost utility of health technologies for children and adolescents based on societal preferences in Hungary.

EQ-5D-Y Value Set for Germany

BACKGROUND

Demand is increasing for youth-specific preference-based health-related quality-of-life measures for inclusion in evaluations of healthcare interventions for children and adolescents. The EQ-5D-Youth (EQ-5D-Y) has the potential to become such a preference-based measure.

OBJECTIVE

This study applied the recently published EQ-5D-Y valuation protocol to develop a German EQ-5D-Y value set and explored the differences between values given to youth health by parents and non-parents.

METHODS

To elicit EQ-5D-Y health state preferences, a representative sample of 1030 adults of the general population completed a discrete choice experiment (DCE) online survey, and 215 adults participated in face-to-face interviews applying composite time trade-off (cTTO). Respondents were asked to consider a 10-year-old child living in the health states. DCE data were modelled using a mixed logit model. To derive the value set, DCE latent scale values were anchored onto adjusted mean cTTO values using a linear mapping approach.

RESULTS

Adult respondents considered pain/discomfort and feeling worried/sad/unhappy as the two most important dimensions in terms of youth health. Adjusted mean cTTO values ranged from - 0.350 for health state 33333 to 0.970 for health state 21111. The EQ-5D-Y value set showed a logical order for all parameter estimates, and predicted values ranged from - 0.283 to 1. Differences in preferences by parental status were mainly observed for cTTO results, where mean values were larger for parents than for non-parents.

CONCLUSIONS

Applying the valuation protocol, a German EQ-5D-Y value set with internally consistent coefficients was developed. This enables the instrument to be used in economic evaluations of paediatric healthcare interventions.

Estimating an EQ-5D-Y-3L Value Set for China

INTRODUCTION

The standard EQ-5D-Y-3L valuation protocol applies DCE data as the primary preference source to model the relative importance of dimensions while cTTO data served to anchor the DCE coefficients onto the QALY scale. This study aims to estimate an EQ-5D-Y-3L value set for China following this protocol, but with a larger cTTO design to better understand the role of cTTO data in estimating EQ-5D-Y-3L value sets.

METHODS

In total, 150 choice sets and 28 EQ-5D-Y-3L health states were valued using DCE and cTTO methods with two independent samples, respectively. General public from 14 different regions were recruited using quota sampling method to achieve representativeness. We compared two modelling strategies: (1) fit the DCE data with mixed logit model with correlated coefficients and a subsequent mapping procedure for anchoring; (2) fit the DCE and TTO data jointly in a hybrid model. Two evaluation criteria (1) coefficient significance and monotonicity; (2) prediction accuracy of the observed cTTO values were used to select the value set.

RESULTS

In total, 1476 individuals participated in the study, with 1058 participated the DCE interview and 418 participated the cTTO interview. The highest mean TTO value was 0.924 for state 11112 and the lowest mean TTO value was - 0.088 for state 33333. The hybrid model with an A3 term performed the best and was selected as the value set.

DISCUSSION

Following the international protocol and using a larger cTTO design, this study established the EQ-5D-Y-3L value set using a hybrid model for China. Future EQ-5D-Y-3L valuation study could consider using a larger cTTO design for estimating the value set.

An EQ-5D-5L Value Set for Belgium

OBJECTIVE

This study aimed to establish a Belgian EQ-5D-5L value set based on the preferences of the adult Belgian general population.

METHODS

The most recent EuroQol Valuation Technology (EQ-VT 2.1) protocol for EQ-5D-5L valuation studies was followed. Computer-assisted personal interviews were carried out in a representative sample of the adult Belgian population. Potential respondents were randomly selected from the National Register using a multistage, stratified, cluster sampling with unequal probability design. Each respondent valued 10 or 11 health states using composite time trade-off (cTTO) and 14 health states in seven paired choice tasks using a discrete choice experiment (DCE). Different model specifications were explored and assessed based on logical consistency, goodness of fit, predictive accuracy and theoretical considerations.

RESULTS

A total of 892 respondents were included in the analyses. The sample was representative of the Belgian adult population in terms of age, sex, region of residence, educational attainment, labour market status, self-assessed health status and health-related quality of life (HRQoL). The preferred model specification was a hybrid (DCE and cTTO data combined) multiplicative eight-coefficient model with intercept random effects and correction for heteroskedasticity. Values range from - 0.532 to 1. Loss of HRQoL is highest in the dimension pain/discomfort, closely followed by anxiety/depression.

CONCLUSIONS

This study developed a Belgian EQ-5D-5L value set, based on the preferences of the Belgian adult general population. It provides opportunities for future clinical and economic evaluations in healthcare, for the measurement of patient-reported outcomes and for population health assessments.

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

OBJECTIVES

The aim of this study was to compare the responsiveness of EQ-5D-3L (3L) with EQ-5D-5L (5L) descriptive systems and value sets in two independent samples (rehabilitation and stroke patients).

METHODS

Descriptive system results were compared cross-sectionally, and descriptive responsiveness was tested by calculating changed level responses ('moves') from baseline to follow-up, proportion of improved patients, Paretian Classification of Health Change (PCHC), and probability of superiority (PS). Responsiveness of values based on nine country-specific value sets was assessed by standardized response mean (SRM) and standardized effect size (SES). Relative efficiency of 5L over 3L was assessed by calculating ratios of the SRM and SES statistics.

RESULTS

Descriptive comparisons confirmed earlier evidence and showed a consistent overestimation of health problems in 3L. Descriptive responsiveness improved with 5L in terms of moves per respondent, proportions of improved patients and PS, whereas PCHC showed mixed results. Better value responsiveness statistics were observed for 5L in rehabilitation patients for all value sets. In stroke patients, 3L showed better responsiveness statistics compared with 5L. Relative efficiency results were moderately to strongly better with 5L for rehabilitation, and slightly to moderately better with 3L for stroke.

CONCLUSIONS

Descriptive results were the main driver of 3L-5L responsiveness differences. Responsiveness of 3L was influenced by the 'confined to bed' label and the overestimation bias of 3L, which affected all responsiveness results. This may impact quality-adjusted life-year (QALY) estimations, leading to over- or underestimations of QALYs gained, depending on the condition and condition severity. QALY calculations based on 5L data will result in more accurate estimates.

Development and economic evaluation of a patient-centered care model for children with Duchenne’s Muscular Dystrophy: A quasi-experimental study protocol (Preprint)

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare progressive muscular disease that primarily affects boys. A lack of comprehensive care for patients living with DMD is directly associated with a compromised quality of life (QoL) for those affected and their caregivers. This disease also has a huge economic impact on families as its treatment requires substantial direct, indirect, and informal care costs.

OBJECTIVE

This study presents a protocol developed to evaluate the feasibility and efficacy of a patient-centered care (PCC) model for children with DMD. The care model was designed with the aim to empower families, improve QoL, and reduce economic burden on their families.

METHODS

This study is planned as a quasi-experimental study that will enroll 70 consecutive families with boys (aged 5-15 years) with DMD visiting a tertiary care center. The study is being conducted in 2 phases (preintervention and postintervention phases, referred to as phase 1 and phase 2, respectively). During phase 1, the patients received routine care. The study is now in phase 2, with the intervention currently being administered. The intervention is based on the PCC model individualized by the intervention team. The model has a comprehensive DMD telecare component that includes teleconsultation as one of its key components to reduce in-person physician visits at the health facility. Teleconsultation is especially beneficial for late-ambulatory and nonambulatory patients. Data on economic burden are being collected for out-of-pocket expenses for both phases during in-person visits via telephone or messaging apps on a monthly basis. QoL data for patients and their primary caregivers are being collected at 3 time points (ie, time of enrollment, end of phase 1, and end of phase 2). Outcome measures are being assessed as changes in economic burden on families and changes in QoL scores.

RESULTS

Participant recruitment began in July 2021. The study is ongoing and expected to be completed by March 2023. The findings based on baseline data are expected to be submitted for publication in 2023.

CONCLUSIONS

This paper outlines a research proposal developed to study the impact of a PCC model for patients with DMD in low- and middle-income countries (LMICs). This study is expected to provide evidence of whether a multicomponent, patient-centric intervention could reduce economic burdens on families and improve their QoL. The results of this study could guide policy makers and health professionals in India and other LMICs to facilitate a comprehensive care program for patients living with DMD. The economic impact of a rare disease is an important consideration to formulate or evaluate any health policy or intervention related to new treatments and financial support schemes.

TRIAL REGISTRATION

Clinical Trials Registry India (ICMR-NIMS) CTRI/2021/06/034274; https://www.ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=56650.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/42491.

A Systematic Review of the Methodologies and Modelling Approaches Used to Generate International EQ-5D-5L Value Sets

BACKGROUND

The international protocol for valuing EQ-5D-5L focuses upon prescribed preference elicitation methods and design. However, there are no recommendations around sampling, recruitment, data analysis or modelling to generate the EQ-5D-5L value set. This review examines methods used to generate international EQ-5D-5L values sets, across sampling, recruitment, data analysis, modelling, assessing model performance and selection of the recommended value set.

METHODS

All published EQ-5D-5L value sets were identified by a systematic search and confirmed by the EuroQol Group. Data were extracted to assess sampling, recruitment, preference elicitation techniques and design, data analysis, modelling, assessing model performance, and vale set selection. These are summarised in tables.

RESULTS

The review included 29 studies with 27 value sets generated using time-trade-off (TTO) data (n = 10) only or using a hybrid model that combines TTO and discrete choice experiment data (n = 17). TTO data were most commonly estimated using a heteroscedastic Tobit model with censoring at - 1, and the hybrid model using a specially created program. Model performance was generally assessed using goodness of fit, logical consistency and significance of coefficients, suitability of the model for the data characteristics and parsimony, though not all selected models account for the specific characteristics of the data.

DISCUSSION

Different assessments of model performance and reasoning are provided for the selection of the recommended value set for a country. This raises the question of valid criteria for selecting a recommended value set and whether this should rely upon researchers' recommendations when value sets are often used to inform public policy.

Exploring the Comparability of Face-to-Face Versus Video Conference-Based Composite Time Trade-Off Interviews: Insights from EQ-5D-Y-3L Valuation Studies in Belgium and Spain

Background

Face-to-face interviews are recommended for the collection of composite time trade-off (cTTO) data. The coronavirus disease 2019 (COVID-19) social distancing measures made researchers consider videoconferencing interviews as an alternative mode of administration, but little evidence about the implementation of videoconferencing in valuation studies is available. This study provides insights into the effect of videoconferencing on the quality of data, evaluating interviewers’ and respondents’ engagement level in videoconferences compared with face-to-face interviews.

Methods

We used cTTO data collected in Belgium and Spain following the EQ-5D-Y-3L valuation protocol. Due to the COVID-19 pandemic, both projects interrupted the face-to-face data collection before reaching the target sample. The remaining interviews were conducted by videoconference. We compared both modes of administration in terms of interviewers’ engagement (task duration and number of moves in each example) and respondents’ engagement (task duration and proportions of specific response values, in half-year units). To minimise interviewers’ learning effects, we split our sample into three groups: (1) first 20 interviews conducted face-to-face; (2) subsequent interviews conducted face-to-face; and (3) videoconferencing interviews.

Results

The comparison between videoconferencing and subsequent face-to-face interviews showed the interviewer’s engagement was not affected by the mode of administration as almost no significant results were found either in the task duration or the numbers of moves shown in the examples. Similarly, none of the respondents’ task duration or proportion of specific responses or half-year units were affected by the mode of administration in either of the two countries.

Conclusions

No evidence suggested that the quality of cTTO data is reduced when using videoconferencing compared with face-to-face interviews.

Why Do Adults Value EQ-5D-Y-3L Health States Differently for Themselves Than for Children and Adolescents: A Think-Aloud Study

OBJECTIVES

Following protocol, adults value EQ-5D-Y-3L health states from the perspective of a 10-year-old child. It remains unclear why adults value health states differently for themselves than for a 10-year-old child and whether the latter perspective is representative of adults' preferences for the 8 to 15 years age range of the EQ-5D-Y-3L. This study examines the reasons underlying (potential) differences in adults' health-state preferences for themselves, a 10-year-old child, and 15-year-old adolescent.

METHODS

We conducted semistructured interviews using a think-aloud protocol with 25 participants who performed valuation tasks in July 2020 to August 2020. Using the Framework Method, we developed 28 categories grouped under 5 themes that illustrated the differences emerging from the interviews.

RESULTS

Participants (A) deemed it more straining to perform valuation tasks for a 10-year-old child and 15-year-old adolescent than for themselves, (B) had a stable self-image, but varied in whom they imagined as 10-year-old child and 15-year-old adolescent, (C) focused on different dimensions and levels for a 15-year-old adolescent than for a 10-year-old child and themselves, (D) had various thoughts about nonhealth-related factors that influenced their preferences, and (E) gave up relatively few life-years for a 10-year-old child and 15-year-old adolescent, also to avoid others bearing a grudge against them.

CONCLUSIONS

Our results indicate that differences in adults' health-state preferences for themselves and a 10-year-old child largely result from differences in thoughts about nonhealth-related factors. They further indicate that health-state preferences for a 10-year-old child may not be representative of such preferences for the full EQ-5D-Y-3L age range.

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.