EuroQol Protocols for Time Trade-Off Valuation of Health Outcomes

A Direct Comparison Between Discrete Choice With Duration and Composite Time Trade-Off Methods: Do They Produce Similar Results?

OBJECTIVES

Discrete choice experiments including a duration attribute (DCEd) represent a promising candidate method for valuing health-related quality-of-life instruments. However, it has not been established that DCEd can produce similar results as composite time trade-off (cTTO) or EuroQol Valuation Technology (EQ-VT) valuations of the EQ-5D-5L instrument. This study provides a direct comparison between cTTO and EQ-VT, and DCEd valuation methods.

METHODS

An EQ-VT study was conducted in Trinidad and Tobago to value the EQ-5D-5L. 1079 respondents each completed 10 cTTO tasks and 12 discrete choice experiments tasks without a duration attribute. A separate sample of 970 respondents each completed 18 split-triplet DCEd tasks. Several regression models were applied to the EQ-VT data, and the DCEd data were analyzed using mixed logit models with an exponential discount rate. The estimated values were compared using scatterplots and Bland-Altman plots.

RESULTS

The ordering of dimensions was identical in level 5 for cTTO/EQ-VT and DCEd models, with pain/discomfort being the most important dimension and usual activities being least important. cTTO/EQ-VT models produced a value for state 55555 ranging between -0.52 and -0.69, whereas this was -0.543 for the nonlinear mixed logit model for the DCEd data. Scatterplots and Bland-Altman plots suggested excellent agreement between cTTO/EQ-VT and DCEd-based estimates.

CONCLUSIONS

CTTO/EQ-VT and DCEd valuations produce similar results when correcting DCEd for nonlinear time preferences. The ordering of importance of the dimensions and scale are identical, suggesting that the 2 methods measure the same construct and produce similar results.

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.

Beyond 10-year lead-times in EQ-5D-5L: leveraging alternative lead-times in willingness-to-accept questions to capture preferences for worse-than-dead states and their implication

BACKGROUND

A fixed 10-year lead-time in composite time-trade-off (C-TTO) tasks might compromise the precision of utility values below - 1. This study explored how alternative lead-times (ALTs) influence EQ-5D-5L value sets and their implications in economic evaluations.

METHODS

Leveraging data from Taiwan's EQ-5D-5L valuation and capitalizing on its exploratory willingness-to-accept question, we explored participants' quantification of "worse-than-dead (WTD)" health states with ALTs up to 50 years. We then derived alternative value sets incorporating these ALTs through interval regression and compared them against those from conventional models. To evaluate their impact on health change valuation, we simulated utility differences for all possible EQ-5D-5L health-state-pairs using each value set.

RESULTS

With a salient floor effect observed in the C-TTO values, the model with ALT led to a wider range of predicted utilities ( - 2.3897 ~ 1), compared with those of conventional models (generalized least squares (GLS):  - 0.7773 ~ 1; Tobit-GLS:  - 0.9583 ~ 1). Compared to the Tobit-GLS model, the model with ALT increased the numerical distance in 80% of health-state-pairs, with 11% decreasing and 9% altering direction (e.g., positive to negative) in utility differences.

CONCLUSIONS

While ALTs offer insights into patient preferences, their integration into economic evaluations might require rescaling. Future research should prioritize advanced rescaling methods or enhanced elicitation strategies for populations with substantial censoring. This is pivotal for improving the elicitation of extreme WTD states and accurately discerning the relative distances between health states. Countries developing EQ-5D-5L value sets should consider pilot studies and incorporating region-specific questions on social determinants, especially where pronounced floor effects are suspected.

Scale and rate heterogeneity in the EQ-5D-5L valuation

OBJECTIVES

To estimate values on a quality-adjusted life year (QALY) scale using individual preference evidence, choice analyses typically include ancillary parameters, such as scale factors and discount rates. These parameters potentially differ among respondents. In this study, we investigated how allowing heterogeneity in scale and rate affects the estimation of EQ-5D-5L values.

METHODS

Using the first wave of the 2016 EQ-5D-5L valuation study (N = 1017), we estimated a conditional logit (CL) model and three mixed logit models: random scale, random rate, and bivariate. Prior to the exploratory study, we hypothesized that scale and rate are correlated and that allowing heterogeneity in both parameters decreases the number of insignificant incremental effects. We confirmed the exploratory findings by re-estimating these models using paired comparison responses from a second wave (N = 1229).

RESULTS

Scale and rate exhibited significant heterogeneity and were positively correlated. As hypothesized, allowing this heterogeneity improved the face validity of the EQ-5D-5L value set by reducing the number of insignificant incremental effects (from 6 to 2 p-values > 0.05; out of 20). Nevertheless, the CL and bivariate mixed logit estimates are highly correlated and concordant (Pearson correlation coefficient of 0.897, Spearman correlation coefficient of 0.888, Lin's concordance coefficient of 0.763).

CONCLUSIONS

Allowing this heterogeneity adds three parameters to the estimation (two variances and a correlation) and improves the face validity of the EQ-5D-5L values. This finding may influence experimental design and choice analysis in health valuation more generally.

Valuation of Multi-Dimensional Health States With a Bolt-On: Is There a Shortcut?

OBJECTIVES

To use the EQ-5D questionnaire with bolt-on dimensions in economic evaluation studies, new value sets are needed. In this study, we explored the feasibility of a new approach called the scaling factor model, which estimates bolt-on value sets using estimated EQ-5D dimensional weights.

METHODS

We designed a 2-arm study, inviting university students to value health states with and without bolt-on items using the composite time trade-off method. We selected 25 health states from an orthogonal array and added the 5 mildest EQ-5D states in the design. In arm 1, EQ-5D without self-care and standard EQ-5D states were valued, and in arm 2, standard EQ-5D states and EQ-5D with vision were valued. By arm, we compared the mean observed values of health states with and without bolt-on item. Next, by arm, we estimated value sets for the EQ-5D with bolt-on states using both standard model and scaling factor model. Model performances were compared in terms of prediction accuracy and correlation with likelihood-based mean values.

RESULTS

Adding a five-level bolt-on to EQ-5D resulted in statistically lower values. This effect was consistent across 2 arms and bolt-on items. The scaling factor models outperformed the standard models in all statistics.

CONCLUSIONS

The scaling factor model offers a methodologically viable and low-cost option for producing value sets for EQ-5D supplemented with bolt-on items. Future studies should further test this method using other bolt-on items and more relevant study populations.

Estimating the monetary value of a Quality-Adjusted Life-Year in Quebec

BACKGROUND

The value of a Quality-Adjusted Life-Year (QALY) is of great importance for the healthcare system. It helps when it comes to defining a cost-effectiveness threshold for the evaluation of health technologies. No willingness-to-pay value for a QALY exists in the province of Quebec, Canada.

OBJECTIVES

In this paper, we empirically investigated the monetary value of a QALY for the population of Quebec.

METHODS

Based on the Short-Form 6-Dimension version 2 (SF-6Dv2), we conducted an online survey with a representative adult sample living in Quebec. We used a time trade-off (TTO) combined with contingent valuation (CV), and a discrete choice experiment (DCE) to assess both the population's willingness to pay (WTP) for one QALY and the marginal WTP for health attributes. A health utility algorithm using hybrid regression was developed to determine a preference-based value set for health states.

RESULTS

Main analysis was conducted on 993 answers for the CV and 2143 answers for the DCE. The willingness-to-pay per QALY varied from CA$ 47,048.84 (CI: 21,554.38; 72,543.30) for CV to CA$ 73,936.87 (CI: 63,105.40; 84,768.35) for DCE. Among the 6 dimensions of the SF-6Dv2, marginal WTP varied from CA$ 4499.15 (CI: 2975.06; 6023.25) for more role accomplishment in daily activities to CA$ 15,867.12 (CI: 13,825.75; 17,908.49) for less pain. Robustness check with multiple alternative samples, as well as alternative health utility algorithms, showed that the results were robust and the DCE method provided 50% larger results than the CV method, although confidence intervals overlap.

CONCLUSION

This paper provides useful information for decision-makers on the monetary value of a QALY in Quebec.

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.

The effect of duration and time preference on the gap between adult and child health state valuations in time trade-off

Composite time trade-off (cTTO) utilities have been found to be higher when adults value health states for children than for themselves. It is not clear if these differences reflect adults assigning truly higher utilities to the same health state in different perspectives, or if they are caused by other factors, which are not accounted for in the valuation procedure. We test if the difference between children's and adults' cTTO valuations changes if a longer duration than the standard 10 years is used. Personal interviews with a representative sample of 151 adults in the UK were conducted. We employed the cTTO method to estimate utilities of four different health states, where adults considered states both from their own and a 10-year-old child's perspective, for durations of 10 and 20 years. We corrected the cTTO valuations for perspective-specific time preferences in a separate task, again for both perspectives. We replicate the finding that cTTO utilities are higher for the child perspective than for the adult perspective, although the difference is only significant when controlling for other variables in a mixed effects regression. Time preferences are close to 0 on average, and smaller for children than adults. After correcting TTO utilities for time preferences, the effect of perspective is no longer significant. No differences were found for cTTO tasks completed with a 10- or 20-year duration. Our results suggest that the child-adult gap is partially related to differences in time preferences and, hence, that correcting cTTO utilities for these preferences could be useful.

Estimation of health utility values for alopecia areata

PURPOSE

Alopecia areata (AA) is an autoimmune-mediated inflammatory dermatological disease characterised by non-scarring hair loss affecting the scalp and sometimes other hair-bearing sites. This study aimed to elicit health state utility values (HSUVs) from the UK general population for AA using time trade off (TTO) interviews.

METHODS

Vignette descriptions of health states defined by the extent of hair loss were developed (as well as one describing caregiver burden). These were developed using data from standardised patient reported outcome (PRO) measures, a literature review and qualitative interviews. Health states were defined based on the severity of alopecia tool (SALT), which assesses extensiveness of scalp hair loss. HSUVs were then elicited for each health state in TTO interviews with the UK public.

RESULTS

One caregiver and five patient health states were developed based on the literature review findings, clinical trial PRO (Hospital Anxiety and Depression Scale and Alopecia Areata Patient Priority Outcomes Questionnaire) data and qualitative interviews with patients (N = 11), clinical experts (N = 4) and caregivers of adolescents with AA (N = 10). These data showed a more severe impact among patients with more extensive hair loss. One hundred and twenty participants evaluated the vignettes in TTO interviews. Patient HSUVs ranged from 0.502 for the most extensive hair loss health state (SALT 50-100 + eyebrow and eyelash loss) to 0.919 (SALT 0-10) for the mildest health state. The caregiver HSUV was 0.882.

CONCLUSION

Quantitative and qualitative data sources were used to develop and validate vignettes describing different AA health states. Patient and caregiver HSUVs demonstrate a large impact associated with AA, especially for states defined by more extensive hair loss.

Outcome Trajectories after Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is the most morbid of all stroke types with a high early mortality and significant early disability burden. Traditionally, outcome assessments after ICH have mirrored those of acute ischemic stroke, with 3 months post-ICH being considered a standard time point in most clinical trials, observational studies, and clinical practice. At this time point, the majority of ICH survivors remain with moderate to severe functional disability. However, emerging data suggest that recovery after ICH occurs over a more protracted course and requires longer periods of follow-up, with more than 40% of ICH survivors with initial severe disability improving to partial or complete functional independence over 1 year. Multiple other domains of recovery impact ICH survivors including cognition, mood, and health-related quality of life, all of which remain under studied in ICH. To further complicate the picture, the most important driver of mortality after ICH is early withdrawal of life-sustaining therapies, before initiation of treatment and evaluating effects of prolonged supportive care, influenced by early pessimistic prognostication based on baseline severity factors and prognostication biases. Thus, our understanding of the true natural history of ICH recovery remains limited. This review summarizes the existing literature on outcome trajectories in functional and nonfunctional domains, describes limitations in current prognostication practices, and highlights areas of uncertainty that warrant further research.

Differences in health utilities between cancer patients and the general population: The case of Quebec using the SF-6Dv2

A considerable debate persists in the literature about whose preferences should be considered in the calculation of quality-adjusted life-years. Some suggest considering only the preferences of the general population, while others advocate for the consideration of those of patients or a combination of both. This study aims to inform and measure the differences in health preferences between cancer patients and the general population in Quebec. A total of 60,976 observations representing the preferences of the general population for various health states were collected and used to develop a new value set using the SF-6Dv2. This value set was generated by combining 34,299 observations with time trade-off (TTO) and 26,677 observations with discrete choice experiment (DCE). Utility scores derived from this value set were compared to those of patients' preferences from a new value set in breast and colorectal patients for the SF-6Dv2. For both patients and the general population, the 'Pain' dimension was the highest contributor to the utility score. However, noticeable differences were observed in the estimates. Estimates of levels 2 and 3 were generally lower for cancer patients, while they were more likely to have greater estimates in severe levels. Significant differences in utility scores were also noticed with the general population showing higher mean utility scores for the same health states. These differences increased as the health states worsened. This study sheds light on the existing differences in preferences between cancer patients and the general population of Quebec for a better consideration in healthcare decision-making.

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.

Bridging and Validation of the Specific Graves Ophthalmopathy Quality of Life Questionnaire With Health State Utility Values

OBJECTIVE

In thyroid eye disease (TED), inflammation and expansion of orbital muscle and periorbital fat result in diplopia and proptosis, severely impacting patient quality of life (QOL). The reported health state utility (HSU) scores, which are QOL measures, allow quantification of TED impact and improvement with therapies; however, no current QOL instrument has been validated with HSU scores for TED. Here, we used the disease-specific Graves Ophthalmopathy Quality of Life (GO-QOL) questionnaire and HSU scores to validate QOL impact.

METHODS

The GO-QOL scores from patients in 2 randomized, masked, placebo-controlled teprotumumab trials (N=171) were compared with 6 HSU values based on severity of proptosis/diplopia in those studies. Patient GO-QOL and HSU scores were compared at baseline and after 6-month treatment via regression analyses. GO-QOL and HSU scores were correlated for validation and quantification of QOL impact by severity state and to estimate quality-adjusted life year improvement.

RESULTS

GO-QOL scores were correlated with TED severity, indicating that worse severity was associated with lower (worse) GO-QOL scores. Less severe health states were represented by higher (better) GO-QOL scores. Importantly, GO-QOL scores were positively correlated with utility scores of the 6 health states, allowing for conversion of the GO-QOL scores to utility scores. A positive (improved) 0.013 utility change was found for each 1-point (positive) improvement in GO-QOL score produced by teprotumumab versus placebo.

CONCLUSION

Patients with moderate-to-severe active TED health states demonstrate increasing TED severity associated with declining utility values and worsening GO-QOL scores. These results indicate that the GO-QOL scores can be used to bridge to the HSU scores for benefit quantification.

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 time trade-off study to determine health-state utilities of transplant recipients with refractory cytomegalovirus infection with or without resistance

BACKGROUND

Health-state utility values (HSUVs) for post-transplant refractory cytomegalovirus (CMV) infection (with or without resistance [R/R]) were determined using a time trade-off (TTO) survey completed by 1,020 members of the UK general public.

METHODS

Existing literature and qualitative interviews with clinicians experienced in treating R/R CMV were used to develop initial draft vignettes of health states. The vignettes were refined to describe three clinical states of R/R CMV: clinically significant and symptomatic (CS-symptomatic CMV); clinically significant and asymptomatic (CS-asymptomatic CMV); and non-clinically significant (non-CS CMV). Each clinical state was valued independently and combined with three events of interest: graft-versus-host disease; kidney graft loss; and lung graft loss to generate twelve vignettes. The final vignettes were evaluated by a sample of the UK general public using an online TTO survey. Exclusion criteria were applied to the final data to ensure that responses included in the analysis met pre-defined quality control criteria.

RESULTS

Overall, 738 participants met the inclusion criteria and were included in the analysis. The sample was representative of the UK general population in terms of age and sex. Non-CS CMV had the highest mean HSUV (95% confidence interval) (0.815 [0.791, 0.839]), followed by CS-asymptomatic CMV (0.635 [0.602, 0.669]), and CS-symptomatic CMV (0.443 [0.404, 0.482]). CS-symptomatic CMV with lung graft loss had the lowest mean HSUV (0.289), with none of the health states considered on average worse than dead.

CONCLUSIONS

Post transplant R/R CMV has substantial impact on the health-related quality of life of patients. The utility values obtained in this study may be used to support economic evaluations of therapies for R/R CMV infection.

Health State Utilities Associated with False-Positive Cancer Screening Results

INTRODUCTION

Early cancer detection can significantly improve patient outcomes and reduce mortality rates. Novel cancer screening approaches, including multi-cancer early detection tests, have been developed. Cost-utility analyses will be needed to examine their value, and these models require health state utilities. The purpose of this study was to estimate the disutility (i.e., decrease in health state utility) associated with false-positive cancer screening results.

METHODS

In composite time trade-off interviews using a 1-year time horizon, UK general population participants valued 10 health state vignettes describing cancer screening with true-negative or false-positive results. Each false-positive vignette described a common diagnostic pathway following a false-positive result suggesting lung, colorectal, breast, or pancreatic cancer. Every pathway ended with a negative result (no cancer detected). The disutility of each false positive was calculated as the difference between the true-negative and each false-positive health state, and because of the 1-year time horizon, each disutility can be interpreted as a quality-adjusted life-year decrement associated with each type of false-positive experience.

RESULTS

A total of 203 participants completed interviews (49.8% male; mean age = 42.0 years). The mean (SD) utility for the health state describing a true-negative result was 0.958 (0.065). Utilities for false-positive health states ranged from 0.847 (0.145) to 0.932 (0.059). Disutilities for false positives ranged from - 0.031 to - 0.111 (- 0.041 to - 0.111 for lung cancer; - 0.079 for colorectal cancer; - 0.031 to - 0.067 for breast cancer; - 0.048 to - 0.088 for pancreatic cancer).

CONCLUSION

All false-positive results were associated with a disutility. Greater disutility was associated with more invasive follow-up diagnostic procedures, longer duration of uncertainty regarding the eventual diagnosis, and perceived severity of the suspected cancer type. Utility values estimated in this study would be useful for economic modeling examining the value of cancer screening procedures.

Preference-based utility weights for the Individualized Neuromuscular Quality of Life Questionnaire (INQoL), with a focus on non-dystrophic myotonia (NDM)

INTRODUCTION

The Individualized Neuromuscular Quality of Life Questionnaire (INQoL) is used to measure quality of life in neuromuscular disorders such as non-dystrophic myotonia (NDM). Here we report methods to estimate utilities, with a focus on NDM, from this questionnaire based on two preference elicitation exercises.

METHODS

Eight items from the INQoL were selected with input from three neuromuscular disorder clinical experts with expertise in treating NDM. A discrete choice experiment (DCE) survey of UK general public respondents (n = 508) described outcomes defined by the INQoL items. The same 8 items were also valued using time trade-off (TTO) face-to-face interviews (n = 200). A hybrid regression modelling approach combined both datasets to inform the utility weights.

RESULTS

Hybrid modelling of DCE and TTO data in conjunction improved out-of-sample predictive accuracy. The selected INQoL utility model indicates substantial disutility associated with all eight dimensions of health, with the greatest losses associated with subjective items such as pain and depression.

DISCUSSION

The hybrid modelling approach allows us to combine data from the two methodologies and maximize the information from each to inform the utility weights for the INQoL. The TTO is the more conventional valuation method, but combined with the larger DCE study produced better descriptive coverage. This is a relatively novel method for estimating weights which we think is particularly well suited to economic evaluations of orphan drugs.

Assessment of health state utilities associated with adult and pediatric acid sphingomyelinase deficiency (ASMD)

INTRODUCTION

Acid sphingomyelinase deficiency (ASMD) type B is a rare genetic disorder leading to enlargement of the spleen and liver, pulmonary dysfunction, and other symptoms. Cost-utility analyses are often conducted to quantify the value of new treatments, and these analyses require health state utilities. Therefore, the purpose of this study was to estimate utilities associated with varying levels of severity of adult and pediatric ASMD type B.

METHODS

Seven adult and seven child health state vignettes describing ASMD were developed based on published literature, clinical trial results, and interviews with clinicians, patients with ASMD, and parents of children with ASMD. The health states were valued in time trade-off interviews with adult general population respondents in the UK.

RESULTS

Interviews were completed with 202 participants (50.0% female; mean age = 41.3 years). The health state representing ASMD without impairment had the highest mean utility for both the adult and child health states (0.92/0.94), and severe ASMD had the lowest mean utility (0.33/0.45). Every child health state had a significantly greater utility than the corresponding adult health state. Differences between adult/child paired states ranged from 0.02 to 0.13. Subgroup analyses explored the impact of parenting status on valuation of child health states.

DISCUSSION

Greater severity of ASMD was associated with lower mean utility. Results have implications for valuation of pediatric health states. The resulting utilities may be useful in cost-utility modeling estimating the value of treatment for ASMD.

Disutility of Cognitive Processing Speed (CPS) Impairment in the Context of Multiple Sclerosis: A Time Trade-Off (TTO) Elicitation Study

Introduction

Cognitive impairment, especially relating to cognitive processing speed, is a major cause of disability in people with multiple sclerosis (MS). Utility values are quantitative estimates of the quality of life experienced in specific health states and are a key component of cost-effectiveness modelling. However, existing health state utility values in MS typically focus on physical ability and are generally derived using generic (not disease-specific) measures of quality of life. The objective of the current study was to generate health state utility values for levels of cognitive impairment. We used a direct utility elicitation approach called the time trade-off (TTO) methodology.

Materials and Methods

Health state descriptions were created following interviews with healthcare professionals, patients, and caregivers in the United States (n=35), and with healthcare professionals in the UK (n=5). Three health states (mild, moderate, and severe impairment) were defined based upon a well-established and validated test for cognitive dysfunction called the Symbol Digit Modalities Test (SDMT) and described using qualitative interview findings. Next, interviews with members of the general public in the UK were conducted to estimate utility values for each health state using the TTO methodology. The procedure was based on the established Measurement and Valuation of Health (MVH) protocol, which generates values on a scale from 0.0 to 1.0.

Results

Mean health state utility values were 0.77 ± 0.24 in "mild impairment" (SDMT 43-40), 0.57 ± 0.26 in "moderate impairment" (SDMT 39-32), and 0.34 ± 0.28 in "severe impairment" (SDMT ≤ 31).

Discussion

Results indicate that the public perceives that health states of cognitive slowing (as observed in MS) are associated with a substantial reduction in affected individuals' health-related quality of life, quantified using the TTO methodology. Future economic modeling should consider how utility impacts of both cognitive and physical disability can be appropriately incorporated.

COVID-19 and EQ-5D-5L health state valuation

BACKGROUND

We investigate whether and how general population health state values were influenced by the initial stages of the COVID-19 pandemic. Changes could have important implications, as general population values are used in health resource allocation.

DATA

In Spring 2020, participants in a UK general population survey rated 2 EQ-5D-5L states, 11111 and 55555, as well as dead, using a visual analogue scale (VAS) from 100 = best imaginable health to 0 = worst imaginable health. Participants answered questions about their pandemic experiences, including COVID-19's effect on their health and quality of life, and their subjective risk/worry about infection.

ANALYSIS

VAS ratings for 55555 were transformed to the full health = 1, dead = 0 scale. Tobit models were used to analyse VAS responses, as well as multinomial propensity score matching (MNPS) to create samples balanced according to participant characteristics.

RESULTS

Of 3021 respondents, 2599 were used for analysis. There were statistically significant, but complex associations between experiences of COVID-19 and VAS ratings. For example, in the MNPS analysis, greater subjective risk of infection implied higher VAS ratings for dead, yet worry about infection implied lower ratings. In the Tobit analysis, people whose health was affected by COVID-19 rated 55555 higher, whether the effect on health was positive or negative.

CONCLUSION

The results complement previous findings that the onset of the COVID-19 pandemic may have impacted EQ-5D-5L health state valuation, and different aspects of the pandemic had different effects.

International Systematic Review of Utility Values Associated with Cardiovascular Disease and Reflections on Selecting Evidence for a UK Decision-Analytic Model

PURPOSE

Evaluating interventions for cardiovascular disease (CVD) requires estimates of its effect on utility. We aimed to 1) systematically review utility estimates for CVDs published since 2013 and 2) critically appraise UK-relevant estimates and calculate corresponding baseline utility multipliers.

METHODS

We searched MEDLINE and Embase (April 22, 2021) using CVD and utility terms. We screened results for primary studies reporting utility distributions for people with experience of heart failure, myocardial infarction, peripheral arterial disease, stable angina, stroke, transient ischemic attack, or unstable angina. We extracted characteristics from studies included. For UK estimates based on the EuroQoL 5-dimension (EQ-5D) measure, we assessed risk of bias and applicability to a decision-analytic model, pooled arms/time points as appropriate, and estimated baseline utility multipliers using predicted utility for age- and sex- matched populations without CVD. We sought utility sources from directly applicable studies with low risk of bias, prioritizing plausibility of severity ordering in our base-case model and highest population ascertainment in a sensitivity analysis.

RESULTS

Most of the 403 studies identified used EQ-5D (n = 217) and most assessed Organisation for Economic Co-operation and Development populations (n = 262), although measures and countries varied widely. UK studies using EQ-5D (n = 29) produced very heterogeneous baseline utility multipliers for each type of CVD, precluding meta-analysis and implying different possible severity orderings. We could find sources that provided a plausible ordering of utilities while adequately representing health states.

CONCLUSIONS

We cataloged international CVD utility estimates and calculated UK-relevant baseline utility multipliers. Modelers should consider unreported sources of heterogeneity, such as population differences, when selecting utility evidence from reviews.

HIGHLIGHTS

Published systematic reviews have summarized estimates of utility associated with cardiovascular disease published up to 2013.We 1) reviewed utility estimates for 7 types of cardiovascular disease published since 2013, 2) critically appraised UK-relevant studies, and 3) estimated the effect of each cardiovascular disease on baseline utility.Our review 1) recommends a consistent and reliable set of baseline utility multipliers for 7 types of cardiovascular disease and 2) provides systematically identified reference information for researchers seeking utility evidence for their own context.

The power of hope: Views of Ovarian Cancer patients on how maintenance therapy Affects their Lives (VOCAL)

Aim: To assess maintenance preference and trade-offs for patients with advanced epithelial ovarian cancer. Methods: Patients completed a time trade-off exercise ranking five maintenance approaches. Patients' preferred approach was compared with alternatives to determine the progression-free time they would trade off to remain on their preferred approach. Results: Of 152 patients (median age 53 years, 68% White), 56% chose one of four maintenance medications, mostly to feel proactive and 44% chose active surveillance. Compared with their preferred approach, patients were willing to trade a mean progression-free time before switching of 2.3 months for once-daily oral medications, 3.2 months for twice-daily oral medications, 5.5 months for intravenous infusions every 3 weeks (iv. q3), 6.1 months for active surveillance and 7.5 months for iv. q3 and twice-daily oral. Conclusion: Findings highlight the importance of patients' awareness of all maintenance approaches and involving them in the decision-making process.

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.

Prognostic Information on Progression to Dementia: Quantification of the Impact on Quality of Life

Background

The increasing interest in early identification of people at risk of developing dementia, has led to the development of numerous models aimed at estimating the likelihood of progression from mild cognitive impairment (MCI) to dementia. It is important to study both the need for and possible outcomes related with such prediction models, including the impact of risk predictions on perceived quality of life (QoL).

Objective

This study aimed to quantify the impact that receiving a risk prediction on progression from MCI to dementia has on QoL.

Methods

A Discrete Choice Experiment (DCE) and Time Trade Off (TTO) study were performed. Participants completed choice tasks related to dementia prognosis while imagining having MCI. We collected DCE data by an online survey, and TTO data via videoconferencing interviews. DCE data were analyzed using a mixed multinomial logit model and were anchored to a health state utility scale using mean observed TTO valuations.

Results

296 people participated in the DCE and 42 in the TTO. Moderate and high predicted dementia risks were associated with decrements in utility (-0.05 and -0.18 respectively), compared to no prognostic information. Low predicted risk was associated with an increase in utility (0.06), as well as the availability of medication or lifestyle interventions (0.05 and 0.13 respectively).

Conclusions

This study shows a significant impact of dementia risk predictions on QoL and highlights the importance of caution when sharing information about expected MCI disease courses.

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.

Can Independently Elicited Adult- and Child-Perspective Health-State Utilities Explain Priority Setting?

OBJECTIVES

Time trade-off (TTO) utilities for EQ-5D-Y-3L health states valued by adults taking a child's perspective are generally higher than their valuations of the same state for themselves. Ceteris paribus, the use of these utilities in economic evaluation implies that children gain less from treatments returning them to full health for a specified amount of time than adults. In this study, we explore if this implication affects individuals' views of priority-setting choices between treatments for adults and children.

METHODS

We elicited TTO utilities for 4 health states in online interviews, in which respondents valued states for a 10-year-old child and another adult their age. Views on priority setting were studied with person trade-off (PTO) tasks involving the same health states. We tested the ability of the subjects' TTO utilities to predict these societal choices in PTO.

RESULTS

There are no significant differences between adult and child health state valuations in our study, but we do observe a substantial preference for treating children over adults in the PTO task.

CONCLUSIONS

Our findings suggest that perspective-dependent health-state utilities only explain a small part of views on priority setting between adults and children. External equity weights might be useful to better explain the higher priority given to children.

Whose Time Trade-Off Should Be Used? Anchoring Discrete Choice Experiment Latent Utilities in Health State Valuation

OBJECTIVES

To compare anchored discrete choice experiment (DCE) utility values using own versus others' time trade-off (TTO) responses in the valuation of SF-6Dv2.

METHODS

A representative sample of the general population was recruited in China. Through face-to-face interviews, both DCE and TTO data were collected from a randomly selected half of the respondents (own TTO sample), whereas only TTO data were collected from the other half (others' TTO sample). Conditional logit model was used to estimate DCE latent utilities. Three anchoring methods, including using the observed and the modeled TTO values for the worst state, and mapping DCE values onto TTO, were used to scale the latent utilities to health utilities. Prediction accuracy was assessed using intraclass correlation coefficient, mean absolute difference, and root mean squared difference compared with the mean observed TTO values between the anchoring results using the own versus others' TTO data.

RESULTS

Demographic characteristics were comparable between the own TTO sample (n = 252) and the others' TTO sample (n = 251). The mean (SD) observed TTO value for the worst state was -0.259 (0.591) for the own TTO sample and -0.236 (0.616) for the others' TTO sample. Anchoring DCE using own TTOs consistently showed a better prediction accuracy than using others' TTOs across the 3 anchoring methods in terms of the intraclass correlation coefficient (0.835-0.873 vs 0.771-0.804), mean absolute difference (0.127-0.181 vs 0.146-0.203), and root mean squared difference (0.164-0.237 vs 0.192-0.270).

CONCLUSION

When anchoring DCE-derived latent utilities onto the health utility scale, respondents' own TTO data would be preferred to TTO data obtained from a different sample.

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.

Second Version of the Short Form 6-Dimension Value Set Elicited From Patients With Breast and Colorectal Cancer: A Hybrid Approach

BACKGROUND

Quality-adjusted life-year instruments help comparison among programs by capturing their effects in terms of utility. Generic instruments are applicable to everyone, and for this reason, they are known to lack sensitivity when measuring gains in some domains. Specific instruments tend to fill this gap but, in domains like cancer, existing instruments are either nonpreferences-based or based on the general population's preferences.

PATIENTS AND METHODS

This study describes the development of a new value set for a well-known and highly used generic instrument, the Second Version of the Short Form 6-Dimension, to better consider the preferences of patients with cancer. In this aim, a hybrid approach combining the time trade-off and the discrete choice experiment was used. The population of interest was the Quebec population, Canada, with breast or colorectal cancer. Their preferences were elicited in 2 periods: before (T1) and 8 days after the beginning of a chemotherapy procedure (T2).

RESULTS

A total of 2808 observations for the time trade-off and 2520 observations for the discrete choice experiment were used. The parsimonious model encompassing the 2 periods was the preferred model. The new value set allows a greater utility range than the EQ-5D-5L and the Second Version of the Short Form 6-Dimension reference value sets and helps in better considering patients experiencing severe health situations. A good correlation between these 2 instruments and other specific cancer instruments (ie, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, QLU-C10D, and Functional Assessment of Cancer Therapy-General) was observed. Significative differences in utility values were also noted within periods and types of cancer.

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.

Health Utilities of Bilateral Severe-to-Profound Hearing Loss with Assistive Devices

Hearing loss is a common sensory disorder in newborns. Early intervention with assistive devices benefits children's auditory and speech performance. This study aimed to measure the health utilities of children with bilateral severe-to-profound hearing impairment with different assistive devices. The descriptions of four hypothetical health states were developed, and their utility values were obtained from healthcare professionals via the visual analogue scale (VAS) and time trade-off (TTO) methods. Thirty-seven healthcare professionals completed the TTO interview and were included in the analysis. The mean utility scores obtained via VAS were 0.31 for no assistive devices, 0.41 for bilateral hearing aids, 0.63 for bimodal hearing, and 0.82 for bilateral cochlear implants. As for the utility scores obtained via TTO, mean values were 0.60, 0.69, 0.81, and 0.90, respectively. None of the four groups had the same VAS- or TTO-elicited utility (p < 0.001). The post hoc test results showed that the difference was significant between any two groups (all p < 0.05). In conclusion, this study elicited health utility of bilateral hearing impairment with different assistive devices using the VAS and TTO methods. The utility values obtained provide critical data for future cost-utility analysis and health technology assessment.

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.

Experience-based health state valuation using the EQ VAS: a register-based study of the EQ-5D-3L among nine patient groups in Sweden

BACKGROUND

The EQ VAS component of the EQ-5D questionnaire has been used to assess patients' valuation of their own health besides its use for self-reporting of overall health status. The objective of the present study was to identify patients' valuation of EQ-5D-3L health states using the EQ VAS in different patient groups over time and in comparison to the general population.

METHODS

Data were obtained from patients from nine National Quality Registers (n = 172,070 patients) at baseline and at 1-year follow-up and compared with data from the general population (n = 41,761 participants). The correlation between EQ VAS scores and EQ-5D-3L index based on the Swedish experience-based VAS value set was assessed. Ordinary least squares (OLS) regression models were used to determine the association between EQ-5D-3L dimensions and EQ VAS valuation.

RESULTS

EQ VAS scores showed consistency with severity of health states both at baseline and at 1-year follow-up in the nine selected EQ-5D-3L health states. The regression models showed mostly consistent decrements by severity levels in each dimension at both time points and similar to the general population. The dimension mainly associated with inconsistency was the self-care severity level three. Problems in the anxiety/depression dimension had the largest impact on overall health status in most of the patient groups and the general population.

CONCLUSION

The study has demonstrated the important role EQ VAS can play in revealing patients' valuation of their health and showed the variation in valuation of EQ-5D-3L dimensions and levels of severity across different patient groups.

Estimation of Health State Utility Values in Fabry Disease Using Vignette Development and Valuation

Background: Health state utilities are measures of health-related quality of life that reflect the value placed on improvements in patients' health status and are necessary for estimation of quality-adjusted life-years. Health state utility data on Fabry disease (FD) are limited. In this study we used vignette (scenario) construction and valuation to develop health state utilities. Objectives: The aim of this study was to use vignette construction and valuation to estimate health state utility values suitable for inclusion in economic models of FD treatments. Methods: Health state vignettes were developed from semistructured qualitative telephone interviews with patients with FD and informed by published literature and input from an expert. Each vignette was valued in an online survey by members of the United Kingdom (UK) general population using the composite time trade-off (TTO) method, which aims to determine the time the respondent would trade to live in full health compared with each impaired health state. Results: Eight adults (50% women) with FD from the UK were interviewed. They were recruited via various approaches, including patient organizations and social media. The interviewees' responses, evidence from published literature, and input from a clinical expert informed the development of 6 health state vignettes (pain, moderate clinically evident FD [CEFD], severe CEFD, end-stage renal disease [ESRD], stroke, and cardiovascular disease [CVD]) and 3 combined health states (severe CEFD + ESRD, severe CEFD + CVD, and severe CEFD + stroke). A vignette valuation survey was administered to 1222 participants from the UK general population who were members of an external surveying organization and agreed to participate in this study; 1175 surveys were successfully completed and included in the analysis. Responses to TTO questions were converted into utility values for each health state. Pain was the highest valued health state (0.465), and severe CEFD + ESRD was the lowest (0.033). Discussion: Overall, mean utility values declined as the severity of the vignettes increased, indicating that respondents were more willing to trade life-years to avoid a severe health state. Conclusions: Health state vignettes reflect the effects of FD on all major health-related quality-of-life domains and may help to support economic modeling for treatment of FD.

Time trade-off health state utility values for depression: a systematic review and meta-analysis

PURPOSE

This study aims to systematically review the literature on health utility in depression generated by time trade-off (TTO) method and to compare health state vignettes.

METHODS

Systematic literature search was conducted following PRISMA guideline in 2020 November (updated in 2022 March) in Pubmed, Web of Science, PsycInfo, and Cochrane Database of Systematic Reviews. Random effect meta-analysis was conducted to pool vignette-based utility values of mild, moderate, and severe depression and to compare the preferences of depressed and nondepressed population.

RESULTS

Overall, 264 records were found, 143 screened by title and abstract after removing duplicates, 18 assessed full text, and 14 original publications included. Majority of the studies (n = 9) used conventional TTO method, and most of the studies (n = 8) applied 10-year timeframe. Eight studies evaluated self-experienced health (own-current depression). Six studies assessed vignette-based health states of remitted, mild, moderate, and severe depression, half of them applied McSad measure based health description. Altogether, 61 different utility values have been cataloged, mean utility of self-experienced depression states (n = 33) ranged between 0.89 (current-own depression) and 0.24 (worst experienced depression). Pooled utility estimates for vignette-based mild, moderate, and severe depression was 0.75, 0.66 and 0.50, respectively. Meta-regression showed that severe depression (β = -0.16) and depressed sample populations (β =  -0.13) significantly decrease vignette-based utility scores.

CONCLUSION

Our review revealed extent heterogeneity both in TTO methodology and health state vignette development. Patient's perception of depression health states was worse than healthy respondents.

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.

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.

Time trade-off study to establish utility decrements in individuals with a spinal cord injury who perform intermittent catheterisation

AIMS

To generate utility decrements for three attributes associated with catheterisation for individuals with a spinal cord injury (SCI): the process of catheterisation, the physical impact of urinary tract infections (UTIs) and worry associated with hospitalisation.

MATERIALS AND METHODS

Health state vignettes comprising various levels of the three attributes were developed. Two cohorts of respondents, corresponding to people with SCIs and a sample broadly representative of the UK population, were presented with nine vignettes (three vignettes for the mild, moderate and severe health states in addition to a random set of six vignettes). It was assumed no or a nominal decrement was associated with the mild health state. Utility decrements were derived from analysing the data obtained from the online time trade-off (TTO). A proportion of the SCI cohort (n = 57) also completed the EQ-5D-5L questionnaire.

RESULTS

Utility decrements were generated using statistical models for the general population (n = 358), the SCI population (n = 48) and the two populations combined (merged model, n = 406). Results from the two cohorts showed minimal differences. For the merged model, SCI status was not statistically significant. All interaction terms, excluding SCI and the severe level of the physical attribute, were not statistically significant. Compared to the mild level, the greatest utility decrement calculated was the severe level of the emotional (worry) attribute (0.09, p < 0.001) for the SCI population. A significant decrement of 0.02 (p <0.001) was calculated for the moderate level of the emotional attribute for all models. The mean utility score for those with SCI having completed the EQ-5D-5L was 0.371.

LIMITATIONS

Modest sample size of respondents from the SCI population (n = 48).

CONCLUSIONS

Worry associated with hospitalisation had the greatest impact on patients' health-related quality of life (HRQoL). The catheterisation process, such as the lubrication and repositioning of the catheter, also impacted on patients' HRQoL.

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.

Time and lexicographic preferences in the valuation of EQ-5D-Y with time trade-off methodology

In the valuation of EQ-5D-Y-3L, adult respondents are asked to complete composite time trade-off (cTTO) tasks for a 10-year-old child. Earlier work has shown that cTTO utilities elicited in such a child perspective are generally higher than when adults take their own perspective. We explore how differences in time preference in child and adult perspectives could explain this effect. Furthermore, as cTTO valuation in a child perspective involves explicit consideration of immediate death for a child, we also consider how cTTO utilities could be affected by decision-makers lexicographically avoiding death in children. We report the results of an experiment in which 219 respondents valued 5 health states in both adult and child perspectives with either a standard cTTO or a lead-time TTO only approach, in which immediate death is less focal. Time preferences were measured in both perspectives. Our results suggest that utilities were lower when lead-time TTO, rather than cTTO, was used. We find large heterogeneity in time preference in both perspectives, with predominantly negative time preference. The influence of time preferences on utilities, however, was small, and correcting for time preferences did not reduce differences between utilities elicited in both perspectives. Surprisingly, we found more evidence for differences in utilities between adult and child perspectives when lead-time TTO was used. Overall, these results suggest that time and lexicographic preferences affect time trade-off valuation in child and adult perspectives, but are not the explanation for differences between these perspectives. We discuss the implications of our findings for EQ-5D-Y-3L valuation.

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.

Disutility of injectable therapies in obesity and type 2 diabetes mellitus: general population preferences in the UK, Canada, and China

INTRODUCTION

Once-daily and once-weekly injectable glucagon-like peptide-1 receptor agonist therapies (GLP-1 RAs) are established in obesity and type 2 diabetes mellitus (T2DM). In T2DM, both once-daily and once-weekly insulin are expected to be available. This study elicited utilities associated with these treatment regimens from members of the general public in the UK, Canada, and China, to quantify administration-related disutility of more-frequent injectable treatment, and allow economic modelling.

METHODS

Two anchor states (no pharmacological treatment), and seven treatment states (daily oral tablet and generic injectable regimens of variable frequency), with identical outcomes were tested A broadly representative sample of the general public in each country participated (excluding individuals with diabetes or pharmacologically treated obesity). An adapted Measurement and Valuation of Health protocol was administered 1:1 in web-enabled interviews by trained moderators: visual analogue scale (VAS) as a "warm-up", and time trade-off (TTO) using a 20-year time horizon for utility elicitation.

RESULTS

A total of 310 individuals participated. The average disutility of once-daily versus once-weekly GLP-1 RA was - 0.048 in obesity and - 0.033 in T2DM; the corresponding average disutility for insulin was - 0.064. Disutilities were substantially greater in China, relative to UK and Canada.

DISCUSSION

Within obesity and T2DM, more-frequent treatment health states had lower utility. Scores by VAS also followed a logical order. The generated utility values are suitable for use in modelling injectable therapy regimens in obesity and T2DM, due to the use of generic descriptions and assumption of equal efficacy. Future research could examine the reasons for greater administration-related disutility in China.

Time and lexicographic preferences in the valuation of EQ-5D-Y with time trade-off methodology

In the valuation of EQ-5D-Y-3L, adult respondents are asked to complete composite time trade-off (cTTO) tasks for a 10-year-old child. Earlier work has shown that cTTO utilities elicited in such a child perspective are generally higher than when adults take their own perspective. We explore how differences in time preference in child and adult perspectives could explain this effect. Furthermore, as cTTO valuation in a child perspective involves explicit consideration of immediate death for a child, we also consider how cTTO utilities could be affected by decision-makers lexicographically avoiding death in children. We report the results of an experiment in which 219 respondents valued 5 health states in both adult and child perspectives with either a standard cTTO or a lead-time TTO only approach, in which immediate death is less focal. Time preferences were measured in both perspectives. Our results suggest that utilities were lower when lead-time TTO, rather than cTTO, was used. We find large heterogeneity in time preference in both perspectives, with predominantly negative time preference. The influence of time preferences on utilities, however, was small, and correcting for time preferences did not reduce differences between utilities elicited in both perspectives. Surprisingly, we found more evidence for differences in utilities between adult and child perspectives when lead-time TTO was used. Overall, these results suggest that time and lexicographic preferences affect time trade-off valuation in child and adult perspectives, but are not the explanation for differences between these perspectives. We discuss the implications of our findings for EQ-5D-Y-3L valuation.

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.

Protocol for estimating the willingness-to-pay-based value for a quality-adjusted life year to aid health technology assessment in India: a cross-sectional study

INTRODUCTION

To ensure that the evidence generated by health technology assessment (HTA) is translated to policy, it is important to generate a threshold value against which the outcomes of HTA studies can be compared. In this context, the present study delineates the methods that will be deployed to estimate such a value for India.

METHODS AND ANALYSIS

The proposed study will deploy a multistage sampling approach considering economic and health status for selection of states, followed by selection of districts based on Multidimensional Poverty Index (MPI) and identification of primary sampling units (PSUs) using the 30-cluster approach. Further, households within PSU will be identified using systematic random sampling and block randomisation based on gender will be done to select respondent from the household. A total of 5410 respondents will be interviewed for the study. The interview schedule will comprise of three sections including background questionnaire to elicit socioeconomic and demographic characteristics, followed by assessment of health gains, and willingness to pay (WTP). To assess the health gains and corresponding WTP, the respondent will be presented with hypothetical health states. Using time trade off method, the respondent will indicate the amount of time he/she is willing to give up at the end of life to avoid morbidities in the hypothetical health condition. Further, respondents will be interviewed about their WTP for treatment of respective hypothetical conditions using contingent valuation technique. These estimates of health gains and corresponding WTP will then be combined to ascertain the value of WTP per quality-adjusted life year.

ETHICS AND DISSEMINATION

The ethical approval has been obtained from the Institutional Ethics Committee (IEC) of Postgraduate Institute of Medical Education and Research, Chandigarh, India. The study outcomes will be made available for general use and interpretation of HTA studies commissioned by India's central HTA Agency.

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.

Utility Assessment of Moderate to Severe Thyroid Eye Disease Health States

Importance

Thyroid eye disease (TED) results in varying degrees of proptosis and diplopia negatively affecting quality of life (QoL), producing possibly substantial visual changes, disfigurement, and disability.

Objective

To determine the association of varying TED severities with QoL in a non-TED population by assessing health state utility scores.

Design, Setting, and Participants

This qualitative study, conducted from April 20, 2020, to April 29, 2021, assessed health states for active, moderate-severe TED, and values were elicited using time trade-off methods. Six health states of varying severity were determined from 2 placebo-controlled clinical trials (171 patients with TED and clinical activity score ≥4, ±diplopia/proptosis) and refined using interviews with US patients with TED (n = 6). Each health state description was validated by interviews with additional TED patient advocates (n = 3) and physician experts (n = 3). Health state descriptions and a QOL questionnaire were piloted and administered to a general population. Visual analog scales (VASs) were also administered to detect concurrence of the findings.

Main Outcomes and Measures

TED health state utility scores and whether they differ from one another were assessed using Shapiro-Wilk, Kruskal-Wallis, pairwise Wilcoxon rank sum, and paired t tests.

Results

A total of 111 participants completed time trade-off interviews. The mean (SD) utility value was 0.44 (0.34). The lowest (worse) mean utility value was observed in the most severe disease state (constant diplopia/large proptosis) with 0.30 (95% CI, 0.24-0.36), followed by constant diplopia/small proptosis (0.34; 95% CI, 0.29-0.40), intermittent or inconstant diplopia/large proptosis (0.43; 95% CI, 0.36-0.49), no diplopia/large proptosis (0.46; 95% CI, 0.40-0.52), and intermittent or inconstant diplopia/small proptosis (0.52; 95% CI, 0.45-0.58). The highest (best) mean value, 0.60 (95% CI, 0.54-0.67), was observed for the least severe disease state (no diplopia/small proptosis).

Conclusions and Relevance

These findings suggest that patients with active, moderate-severe TED may have substantial disutility, with increasing severity of proptosis/diplopia more likely to have detrimental associations with QoL. These health state scores may provide a baseline for determining QoL improvement in these TED health states (utility gains) treated with new therapies.

Elicitation of Health State Utility Values in Retinitis Pigmentosa by Time Trade-off in the United Kingdom

Introduction

Retinitis pigmentosa (RP) is an inherited retinal pathology associated with "night blindness" and progressive loss of peripheral vision, in some cases leading to complete blindness. Health state utility values are required for activities such as modelling disease burden or the cost-effectiveness of new interventions. The current study aimed to generate utility values for health states of varying levels of functional vision in RP, with members of the general public in the UK.

Methods

Five health states were defined according to standard clinical measures of visual ability. Health state descriptions were developed following interviews with patients with RP in the UK (n=5). Further interviews were conducted for confirmation with healthcare professionals with specific experience of managing patients with RP in the UK (n=2). Interviews with members of the general public in the UK were conducted to value health states. A time trade-off (TTO) process based on the established Measurement and Valuation of Health (MVH) protocol was used. Due to the ongoing COVID-19 pandemic, all interviews were web-enabled and conducted 1:1 by a trained moderator.

Results

In total, n=110 TTO interviews were conducted with members of the UK general public. Mean TTO utility values followed the logical and expected order, with increasing visual impairment leading to decreased utility. Mean values varied between 0.78 ± 0.20 ("moderate impairment"), and 0.33 ± 0.26 ("hand motion" to "no light perception"). Supplementary visual analogue scale (VAS) scores also followed the logical and expected order: mean VAS values varied between 47.95 ± 15.38 ("moderate impairment") and 17.22 ± 12.49 in ("hand motion" to "no light perception").

Discussion

These data suggest that individuals living with RP have substantially impaired quality of life. Utility values for RP have been elicited here using a method and sample that is suitable for economic modelling and health technology assessment purposes.