Employing quality control and feedback to the EQ-5D-5L valuation protocol to improve the quality of data collection

Estimating Australian Population Utilities for Inherited Retinal Disease Using Time Trade-Off

PURPOSE

Inherited retinal disease (IRD) causes progressive loss of visual function, degenerating towards complete blindness. Economic evaluation of gene therapies for rare forms of genetic IRDs have had to rely on health-related quality of life (HR-QoL) estimates from other diseases because there is limited data available for such a rare condition. This study aimed to estimate Australian societal-based utility values for IRD health states that can be used in cost-utility analyses (CUA) using a time trade-off (TTO) protocol adapted from a UK study.

METHODS

The EuroQol Valuation Technology (EQVT) protocol composite TTO (cTTO) framework was followed, which includes worse-than-death (WTD) states and quality control (QC) measures. Preferences were collected from a general population sample of 110 Australian adult participants. Five health state vignettes from the UK study which had been validated with patients and clinicians were presented randomly to participants during videoconferencing (VC) interviews with one of four interviewers. Technical and protocol feasibility were assessed in a pilot of 10 interviews. QC measures were used to monitor interviewers' performance during the study.

RESULTS

One participant withdrew consent. The final analysis was conducted on 109 respondents (including 4 non-traders). The average time to complete the interview was 44.2 minutes (SD 8.7). Participants reported mean visual analogue scale (VAS) scores between 63.15 for 'moderate impairment' and 17.98 for 'hand motion' to 'no light perception'. Mean health state utilities (HSU) varied between 0.76 (SD 0.26) in 'moderate impairment', and 0.20 (SD 0.58) in 'hand motion' to 'no light perception'. Of all HSU evaluations, 14% were considered WTD which most commonly occurred in the most severe visually impaired health state.

CONCLUSION

This study provides valuable information on HSUs across a range of IRD health states from the Australian general population perspective. The utilities obtained in this study can be used as inputs into CUA of IRD therapies.

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.

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.

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.

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.

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.

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.

The Quality of Life among University of the Third Age Students in Poland, Ukraine and Belarus

The aim of this research was to compare the quality of life among University of the Third Age (U3A) students in Poland, where a novel method of educating seniors is being developed, with the quality of life among students at newly established U3As in Belarus and Ukraine, which have copied the Polish model. The research was also conducted to connect a range of socio-demographic variables with two explanatory ones: satisfaction with participation in U3A activities and the overall quality of life. A total of 515 U3A (N13) students from three Eastern European countries—Poland, Ukraine, and Belarus—took part in the research. The overall quality of life of U3A students was researched and expressed in the form of three components: stress level, sense of self-efficacy, and level of satisfaction with life. The following tools were used: PPS10 (Perceived Stress Scale), GSES (General Self-Efficacy Scale), and SWLS (Satisfaction with Life Scale). The research showed a statistically significant difference between the country of residence and the level of satisfaction with life, sense of self-efficacy, and the overall indicator of the quality of life. Polish seniors obtained higher results in all these areas when compared to their counterparts in Ukraine and Belarus.

EQ-VT protocol: one-size-fits-all? Challenges and innovative adaptations used in Egypt: a cross-sectional study

OBJECTIVES

To present the challenges and adaptations done to the EuroQol Valuation Technology (EQ-VT) protocol to fit the Egyptian culture during the extensive pilot phase of the Egyptian EuroQol 5 Dimension five level (EQ-5D-5L) valuation study DESIGN: This study was a cross-sectional, interviewer-administered face-to-face survey of representative Egyptians using the Arabic version of the EuroQol Group Valuation Technology (EQ-VT-2.1) and a country specific questionnaire pertaining to participants' demographics and opinions about health, life and death SETTING: Participants were recruited from workplaces, university campuses, sporting clubs, shopping malls and other public areas from different Egyptian governorates representing all geographical areas of the country.

PARTICIPANTS

A total of 1378 participants were interviewed from July 2019 to March 2020 by 12 interviewers to select a representative sample in terms of: geographical distribution, age and gender, of which 75 participants did not complete the interview, 298 interviews were pilot and 1005 interviews were real of which 974 interviews were used for the valuation study. Two participants did not complete the country-specific questionnaire but completed the valuation protocol; therefore, 1301 interviews were included in the final analysis of country specific questions.

RESULTS

Some modifications were applied to the protocol. The 'wheelchair example' was modified to 'migraine example' since most of the participants in the pilot interviews considered being in a wheelchair 'worse than dead'. There was some ambiguity in the Egyptian translated version for the EQ-5D-5L between levels 4 and 5 of the pain and depression dimensions. This was overcome by using colour coding to express the different levels of severity. A pictorial representation for the EQ-5D-5L health states was used to interview illiterate and less educated participants.

CONCLUSION

In the Egyptian valuation study, the modifications made to the EQ-VT protocol made it feasible and culturally acceptable to the Egyptian participants.

The Danish EQ-5D-5L Value Set: A Hybrid Model Using cTTO and DCE Data

OBJECTIVES

Quality-adjusted life-years (QALYs) are expected to be used for priority setting of hospital-dispensed medicines in Denmark from 2021. The aim of this study was to develop the first Danish value set for the EQ-5D-5L based on interviews with a representative sample of the Danish adult population.

METHODS

A nationally representative sample based on age (> 18 years), gender, education, and geographical region was recruited using data provided by Statistics Denmark. Computer-assisted personal interviews were carried out using the EQ-VT 2.1. Respondents each valued ten health states using composite time trade-off (cTTO) and seven health states using discrete-choice experiment (DCE). Different predictive models were explored using cTTO and DCE data alone or in combination as hybrid models. Model performance was assessed using logical consistency.

RESULTS

A total of 1014 interviews were included in the analyses. The sample was representative of the Danish adult population, though the sample contained slightly more respondents with higher education than in the general population. Only the heteroscedastic censored hybrid model combining cTTO and DCE data yielded consistent results, and hence was chosen for modelling the final Danish value set. The predicted values ranged from - 0.757 to 1, and anxiety/depression was the dimension assigned most value by respondents.

CONCLUSIONS

This study established the Danish EQ-5D-5L value set, which represents the preferences of the Danish general population, and is expected to provide key input for healthcare decision-making in a Danish context.

Valuing health-related quality of life among the Indian population: a protocol for the Development of an EQ-5D Value set for India using an Extended design (DEVINE) Study

INTRODUCTION

Quality-adjusted life year (QALY) has been recommended by the government as preferred outcome measure for Health Technology Assessment (HTA) in India. As country-specific health-related quality of life tariff values are essential for accurate measurement of QALYs, the government of India has commissioned the present study. The aim of this paper is to describe the methods for the Development of an EQ-5D Value set for India using an Extended design (DEVINE) Study. Additionally, this study aspires to establish if the design of 10-time trade-off (TTO) blocks is enough to generate valid value sets.

METHODS AND ANALYSIS

A cross-sectional survey using the EuroQol Group's Valuation Technology (EQ-VT) will be undertaken in a sample of 2700 respondents selected from six different states of India using a multistage stratified random sampling technique. The participants will be interviewed using computer-assisted personal interviewing technique. The TTO valuation will be done using 10 composite TTO (c-TTO) tasks and 7 discrete choice experiment (DCE) tasks. Hybrid modelling approach using both c-TTO and DCE data to estimate the potential value set will be applied. Values of all 3125 health states will be predicted using both the conventional EQ-VT design of 10 blocks of 10 TTO tasks, and an extended design of 18 blocks of 10 TTO tasks. The potential added value of the eight additional blocks in overall validity will be tested. The study will deliver value set for India and assess the adequacy of existing 10-blocks design to be able to correctly predict the values of all 3125 health states.

ETHICS AND DISSEMINATION

The ethical approval has been obtained from Institutional Ethics Committee of PGIMER, Chandigarh, India. The anonymised EQ-5D-5L value set will be available for general use and in the HTAs commissioned by India's central HTA Agency.

Impact of frailty on health-related quality of life 1 year after transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) brings symptom relief and improvement in health-related quality of life (HRQoL) in the majority of patients treated for symptomatic, severe aortic stenosis. However, there is a substantial group of patients that do not benefit from TAVI. The aim of this study is to investigate the impact of frailty on HRQoL 1 year after TAVI.

METHODS

The TAVI Care & Cure Program is an ongoing, prospective, observational study including patients referred for TAVI to our institution. A comprehensive geriatric assessment was performed to evaluate existence of frailty using the Erasmus Frailty Score (EFS). HRQoL was assessed using the EQ-5D-5 L at baseline and 1 year after TAVI.

RESULTS

239 patients underwent TAVI and completed HRQoL assessment 1 year after TAVI. Seventy (29.3%) patients were classified as frail (EFS ≥ 3). In non-frail patients, the EQ-5D-5 L index did not change (0.71(± 0.22) to 0.68(± 0.33) points, P = 0.22); in frail patients, the EQ-5D-5 L index decreased from 0.55(±0.26) to 0.44 points (±0.33) (P = 0.022). Frailty was an independent predictor of deteriorated HRQoL 1 year after TAVI (OR 2.24, 95% CI 1.07-4.70, P = 0.003). In frail patients, the absence of peripheral artery disease (OR 0.17, 95% 0.05-0.50, P = 0.001) and renal dysfunction (OR 0.13, 95% CI 0.04-0.41, P = <0.001) at baseline was associated with improved HRQoL 1 year after TAVI.

CONCLUSION

Frailty is associated with deterioration of HRQoL 1 year after TAVI. Notably, HRQoL did improve in frail patients with no peripheral arterial disease or renal impairment at baseline.

Elicitation of Norwegian EQ-5D-5L values for hypothetical and experience-based health states based on the EuroQol Valuation Technology (EQ-VT) protocol

INTRODUCTION

Norway is one of several European countries that lacks a national value set and scoring algorithm for the EuroQol five dimensions (EQ-5D). Recent studies have found differences between countries in terms of health values or preferences for health states described by instruments such as the EQ-5D. The project aims to model a national value set for the five level version of the EQ-5D based on values elicited from a representative sample of the Norwegian adult general population in terms of region, age, sex and level of education. Using a sampling strategy supporting the collection of values for both hypothetical and experienced health states, the study will have the additional aim of assessing the feasibility of collecting experience-based values in accordance with the latest EQ-5D valuation study protocol, and comparing values with those given for hypothetical health states.

METHODS AND ANALYSIS

Multistage random sampling and quota-sampling will contribute to representativeness. To increase the number of valuations of experienced health states, those with less than perfect health will be oversampled, increasing the total number of interviews from 1000 to 1300-1500. The most recent EQ-5D valuation protocol will be followed which includes computer assisted face-to-face, one-to-one interviews and use of composite time trade-off and discrete choice experiments.

ETHICS AND DISSEMINATION

The study has been reviewed and found to be outside of the scope of the ethics committee and thus not in need of ethical approval. The study findings will be disseminated through peer-reviewed publications, conference presentations and summaries for key stakeholders and partners in the field. The scoring algorithms will be available for widely used statistical software.

Impact of Valvulo-Arterial Impedance on Long-Term Quality of Life and Exercise Performance After Transcatheter Aortic Valve Replacement

BACKGROUND

In aortic stenosis, valvulo-arterial impedance (Zva) estimates the overall left ventricular afterload (valve and arterial component). We investigated the association of Zva (≥5 versus <5 mm Hg mL^-1 m^-2) on quality of life (QOL) and exercise performance (EP) ≥1 year after transcatheter aortic valve replacement (TAVR).

METHODS

The study population consists of 250 TAVR patients in whom baseline Zva and follow-up QOL was prospectively assessed using EuroQOL-5-dimensions instruments; EP was assessed in 192 patients who survived ≥1 year after TAVR using questionnaires related to daily activities. In 124 patients, Zva at 1-year was also available and was used to study the change in Zva (baseline to 1 year) on QOL/EP.

RESULTS

Elevated baseline Zva was present in 125 patients (50%). At a median of 28 (IQR, 17-40) months, patients with elevated baseline Zva were more limited in mobility (88% versus 71%; P=0.004), self-care (40% versus 25%; P=0.019), and independent daily activities (taking a shower: 53% versus 38%, P=0.030; walking 100 meter: 76% versus 54%, P=0.001; and walking stairs: 74% versus 54%, P=0.011). By multivariable analysis, elevated Zva predicted unfavorable QOL (lower EuroQOL-5-dimensions-Utility Index, odds ratio, 1.98; CI, 1.15-3.41) and unfavorable EP (any limitation in ≥3 daily activities, odds ratio, 2.55; CI, 1.41-4.62). After TAVR, the proportion of patients with elevated Zva fell from 50% to 21% and remained 21% at 1 year and was found to be associated with more limitations in mobility, self-care, and daily activities compared with patients with Zva <5 mm Hg mL^-1 m^-2.

CONCLUSIONS

Elevated Zva was seen in half of patients and predicted unfavorable long-term QOL and EP. At 1 year after TAVR, the prevalence of elevated Zva was 21% but remained associated with poor QOL/EP.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

When designing a valuation study, a criterion that has been used for selecting health states for direct valuation is whether the health states are plausible for respondents, because it is assumed that inclusion of implausible states would compromise data quality.

OBJECTIVES

To understand which health states are implausible, and how their values differ from the values of the plausible counterparts.

METHODS

One thousand six hundred Chinese students valued all 3125 health states of the 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) using the EuroQol visual analogue scale. Of these, 890 students also indicated whether each valued state was implausible or not using a binary scale. Additional qualitative interviews were conducted concerning the thought processes involved in the valuation of implausible states. We calculated an implausible score for each state. Then we examined the effect of implausibility on visual analogue scale values by fitting 2 regression models. Two independent researchers analyzed the qualitative transcripts using thematic analysis.

RESULTS

Approximately 30% of the EQ-5D-5L health states were rated as implausible by at least 50% of the respondents, but there was substantial heterogeneity in views about the plausibility of EQ-5D-5L states. Health states with dimensions that conflicted were more likely to be judged as implausible states. Health states that respondents deemed as implausible were more difficult to value and had lower values.

CONCLUSIONS

When respondents found the EQ-5D states to be implausible, they tended to give them lower values. Nevertheless, completely excluding implausible states from a valuation study is not possible because there is a lack of agreement among respondents on which states are implausible.

Test-Retest Reliability of EQ-5D-5L Valuation Techniques: The Composite Time Trade-Off and Discrete Choice Experiments

OBJECTIVES

To explore the test-retest reliability of the composite time trade-off (C-TTO) and discrete choice experiment (DCE) used in the Indonesian five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) valuation study.

METHODS

A representative sample aged 17 years and older was recruited from the Indonesian general population by stratified quota sampling with respect to residence, sex, and age. Trained interviewers conducted computer-assisted face-to-face interviews using the EuroQol valuation technology. Each respondent valued 10 health states using C-TTO and 7 pairs of health states in a DCE exercise. The retest interview was conducted after 2 weeks by the same interviewer. The Wilcoxon matched-pairs signed-rank test, intraclass correlation coefficient, and multilevel regression were applied in comparing the C-TTO test and retest data. For DCE, the analysis of proportions was used.

RESULTS

A total of 226 respondents with characteristics similar to the Indonesian population completed the retest interview. For C-TTO, 82 (95.3%) of 86 health states had no significant mean value differences between test and retest. The mean value of the second test was statistically significantly higher than that of the first test by 0.042. For DCE, 72.5% of responses were identical. DCE retest showed a different pattern concerning the relative importance of the dimensions, whereas the C-TTO remained the same.

CONCLUSIONS

C-TTO is stable over time, whereas in DCE the relative values of the dimensions shift. The results support the use of the C-TTO, in particular the Indonesian EQ-5D-5L value set, and suggest a critical examination of the reliability of DCE results over time.

Use of Computer-Assisted Personal Interviewing and Information Management System in a Survey among HIV High-Risk Groups in India: Strengths, Weaknesses, Opportunities, and Threats Analysis

Objectives:

In India, integrated biological and behavioral surveillance was carried out in 2014–2015 among high-risk key population as a part of second-generation HIV surveillance system. Computer-assisted personal interviewing and integrated information management system were used for the first time in this large national field based survey. We evaluated the strengths and weaknesses of technology use in this survey.

Methods:

Mixed methods comprising of the key informant's interviews and structured data collected from field interviewers were used to do the strengths, weaknesses, opportunities, and threats analysis with defined attributes.

Results:

Despite the challenges, the technology use in this survey was a huge success with respect to data coverage, response rates, real-time data, and acceptance by respondents. However, such techniques require more focus on the competency of human resource, training, and concurrent evaluation systems to get better data quality, time adherence, and effective use of technology.

Conclusion:

The recommendations resulted from this analysis will help for strategic management while designing such systems in field-based community surveys.

The Indonesian EQ-5D-5L Value Set

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sample size determination for EQ-5D-5L value set studies

PURPOSE

The EuroQol 5-Dimension (EQ-5D) is a widely used health status instrument for cost-utility analysis of healthcare interventions. Recently, its 5-Level version (EQ-5D-5L) and a protocol for conducting valuation of its health states were developed. We propose four approaches for estimating the sample size for EQ-5D-5L valuation according to the standardized procedures of the protocol.

METHODS

The first approach is for estimating mean health state utility values with a desired precision level using a regression model. The second approach, empirical in nature, determines a sample size based on mean absolute error in predicting health state values using a large-scale reference study. The last two approaches are for assessing the significance of regression coefficients of health state descriptors and to estimate the regression coefficients with a desired precision for predicting health state utility values.

RESULTS

Using data from a Singaporean study, we estimated parameters that are useful for sample size determination, including the design effect. Each of the approaches was illustrated with examples and pragmatic recommendations were provided.

CONCLUSIONS

Capitalizing on the EQ-5D-5L valuation protocol, we proposed four sample size estimation approaches which can help to decide an appropriate sample size for a value set study.

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

BACKGROUND

The values of the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) are elicited using composite time trade-off and discrete choice experiments. Unfortunately, data quality issues and interviewer effects were observed in the first few EQ-5D-5L valuation studies. To prevent these issues from occurring in later studies, the EuroQol Group established a cyclic quality control (QC) process.

OBJECTIVES

To describe this QC process and show its impact on data quality.

METHODS

A newly developed QC tool provided information about protocol compliance, interviewer effects, and mean values by health state severity. In a cyclic process, this information is initially used to evaluate whether new interviewers meet minimal quality requirements and later to provide feedback about how their performance may be improved. To investigate the impact of this cyclic process, we compared the quality of the data in Dutch and Spanish valuation studies that did not have this QC process with that in the follow-up studies in the same countries that used the QC process. Data quality was measured using protocol violations, variability between interviewers, the proportion of inconsistent responders, and clustering of composite time trade-off values.

RESULTS

In Spain, protocol violations were reduced from 87% in the valuation study to 5% in the follow-up study and in the Netherlands from 20% to 8%. In both countries, interviewers performed more homogeneously in the follow-up studies. The number of inconsistent respondents was reduced by 23.2% in Spain and 23.6% in the Netherlands. Values were less clustered in the follow-up studies.

CONCLUSIONS

The implementation of a strict QC process in EQ-5D-5L valuation studies increases interviewer protocol compliance and promotes data quality.