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.

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.

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.

Health state utilities associated with weight loss: preferences of people with type 2 diabetes and obesity in Japan

AIMS

Health state utilities associated with weight change are needed for cost-utility analyses (CUAs) examining the value of treatments for type 2 diabetes and obesity. Previous studies have estimated the utility benefits associated with various amounts of weight reduction in the US and Europe, but preferences for weight change in Asian cultures may differ from these published values. The purpose of this study was to estimate utilities associated with reductions in body weight based on preferences of individuals with type 2 diabetes and obesity in Japan.

METHODS

Health state vignettes represented type 2 diabetes with respondents' own current weight and weight reductions of 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, and 20%. Utilities were elicited in time trade-off interviews with a sample of respondents in Japan with type 2 diabetes and body mass index (BMI) ≥25 kg/m2 (the cutoff for obesity in Japan).

RESULTS

Analyses were conducted with data from 138 respondents (84.8% male; mean age = 58.0 years; mean BMI = 29.4 kg/m2) from all eight regions of Japan. Utility gains gradually increased with rising percentage of weight reductions ranging from 2.5% to 15%. Weight reductions of 2.5% to 15% resulted in utility increases of 0.013 to 0.048. The health state representing a 20% weight reduction yielded a wide range of preferences (mean utility increase of 0.044). Equations are recommended for estimating utility change based on any percentage of weight reduction (up to 20%) in Japanese people with type 2 diabetes and obesity.

LIMITATIONS

This study was conducted in a sample with limited representation of patients with BMI >35 kg/m2 (n = 13) and relatively few women (n = 21).

CONCLUSION

Results may be used to provide inputs for CUAs examining the value of treatments that are associated with weight loss in patients with type 2 diabetes and obesity in Japan.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Disutilities Associated with Intravenous Iron Infusions: Results from a Time Trade-off Survey and Diminishing Marginal Utility Model for Treatment Attributes in China

Purpose

Treatment process attributes can affect health state utilities associated with therapy. For intravenous iron, used to treat iron deficiency and iron deficiency anemia, research into process attributes is still lacking. This study estimated utilities associated with process attributes for intravenous iron infusions.

Methods

An online survey including seven health state vignettes and time trade-off tasks was administered to participants, who were not patients living with iron deficiency or iron deficiency anemia, from a Chinese online panel. Vignettes used an identical description of iron deficiency and iron deficiency anemia but differed in the annual number of infusions, infusion duration, and infusion-associated risk of hypophosphatemic osteomalacia. Disutilities and their rate of change as the number of infusions increased were examined using a power model.

Results

The survey was completed by 1091 participants. The highest utilities were observed for one annual infusion of 15-30 minutes or 30-60 minutes, without risk of hypophosphatemic osteomalacia (0.754 and 0.746, respectively). In comparison, more infusions and infusions with a risk of hypophosphatemic osteomalacia were associated with lower utilities. Utility continued to decrease, but at a diminishing rate, as the annual number of infusions increased, with utility decrements of 0.006 and 0.002, respectively, when going from zero to one and from four to five infusions per year. All marginal disutilities were small (values <0.01).

Conclusion

This study suggested that treatment attributes of intravenous iron infusions affect health state utilities. Using intravenous iron formulations that allow for fewer and shorter infusions without the risk of hypophosphatemic osteomalacia can reduce the number of visits required and increase patients' quality of life.

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.

A Health State Utility Study to Elicit Societal Values Associated with Pulmonary Hypertension

Aim

Pulmonary hypertension (PH) is a rare, severe, and progressive pulmonary vascular disease, which includes five subgroups with similar presentation. Symptoms include dyspnea, and fatigue, and can significantly impact one's health-related quality of life (HRQL). Although treatments are mainly medical, PH group 4, chronic thromboembolic pulmonary hypertension (CTEPH), can be managed with procedures, ie pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA). Currently, drugs in Europe are only approved for pulmonary arterial hypertension (PAH), and CTEPH therefore the aim of this study was to elicit novel societal health state utilities in the UK for PAH and CTEPH based on disease severity, functional class (FC), clinical events, and treatment procedures specifically for CTEPH.

Material and Methods

Six health states were defined: World Health Organization (WHO)-FC II, WHO-FC III, and WHO-FC IV [defined by the New York Heart Association (NYHA)]; PH-related hospitalization; and "BPA procedure and recovery" and "PEA surgery and recovery". Health states were based on a targeted literature review and two rounds of interviews with clinical experts (N = 4) and patients (N = 6). Draft health states were validated in cognitive debriefing interviews with clinical experts (N = 3). Health states were valued by the UK general public (n = 200), using a visual analogue scale (VAS) and time trade-off (TTO) assessment with the lead time method.

Results

The mean TTO values/utilities were 0.81 (FC II), 0.80 (BPA), 0.78 (PEA), 0.59 (FC III), 0.28 (FC IV), and 0.25 (PH-related hospitalization). Each progression in FC was associated with worse TTO scores.

Conclusion

This study reports societal utility values for PAH and CTEPH in the UK. It provides first utility estimates for states such as BPA procedure and recovery, PEA surgery and recovery and PH-related hospitalization for this population. The results show important distinctions between FC, treatment procedures, and hospitalization, and the significant burden of disease on HRQL.

Valuing the EQ Health and Wellbeing Short Using Time Trade-Off and a Discrete Choice Experiment: A Feasibility Study

OBJECTIVES

The EQ Health and Wellbeing Short (EQ-HWB-S) is a new generic measure that covers health and wellbeing developed for use in economic evaluation in health and social care. The aim was to test the feasibility of using composite time trade-off (cTTO) and a discrete choice experiment (DCE) based on an international protocol to derive utilities for the EQ-HWB-S and to generate a pilot value set.

METHODS

A representative UK general population was recruited. Online videoconference interviews were undertaken where cTTO and DCE tasks were administered using EuroQol Portable Valuation Technology. Quality control (QC) was used to assess interviewers' performance. Data were modeled using Tobit, probit, and hybrid models. Feasibility was assessed based on the distribution of data, participants, and reports of understanding from the interviewer, QC and modeling results.

RESULTS

cTTO and DCE data were available for 520 participants. Demographic characteristics were broadly representative of the UK general population. Interviewers met QC requirements. cTTO values ranged between -1 to 1 with increasing disutility associated with more severe states. Participants understood the tasks and the EQ-HWB-S states; and the interviewers reported high levels of understanding and engagement. The hybrid Tobit heteroscedastic model was selected for the pilot value set with values ranging from -0.384 to 1. Pain, mobility, daily activities, and sad/depressed had the largest disutilities, followed by loneliness, anxiety, exhaustion, control, and cognition in the selected model.

CONCLUSIONS

EQ-HWB-S can be valued using cTTO and DCE. Further methodological work is recommended to develop a valuation protocol specific to the EQ-HWB-S.

Evaluating process utilities for the treatment burden of chemotherapy in multiple myeloma in Japan: a time trade-off valuation study

AIMS

This study estimated the "process utilities" of treatment options for patients with relapsed/refractory multiple myeloma (RRMM) in Japan using the time trade-off (TTO) method. Chimeric antigen receptor (CAR) T cell immunotherapy is available for patients with RRMM who are triple-class exposed (TCE) after treatment with immunomodulatory agents, proteasome inhibitors, and anti-CD38 monoclonal antibodies. However, the impact of available treatment options on health state utilities has not been well characterized, particularly in relation to process utilities.

METHODS

Eight vignettes of health states and daily activity restrictions related to each of the following RRMM therapies were prepared: no treatment, CAR T cell therapy with idecabtagene vicleucel (ide-cel), regular intravenous infusion, and oral administration. A face-to-face survey of healthy Japanese adults who were representative of the general population was conducted. The TTO method was used to evaluate each vignette and to generate utility scores for each treatment regimen.

RESULTS

Three hundred and nineteen respondents participated in the survey (mean age: 44 years [range: 20-64]; female: 50%). Utility scores for no treatment, ide-cel, and oral pomalidomide and dexamethasone (Pd) therapy ranged from approximately 0.7 to 0.8. Utility scores for regular intravenous infusion regimens ranged from 0.50 to 0.56. There was a difference of approximately 0.2 between the utility scores for no treatment/ide-cel/oral administration and regular intravenous infusions.

CONCLUSIONS

Differences in treatment administration across RRMM therapies showed a substantial impact on health state utilities. When quantifying the value of treatments, process utility gains should be considered as an independent factor in health technology assessments.

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.

Quality of Life with Late-Onset Pompe Disease: Qualitative Interviews and General Public Utility Estimation in the United Kingdom

Background: Late-onset Pompe disease (LOPD) is a rare, progressive neuromuscular condition typically characterized by weakness of skeletal muscles, including those involved in respiration and diaphragmatic dysfunction. Individuals with LOPD typically eventually require mobility and/or ventilatory support. Objectives: This study aimed to develop health state vignettes and estimate health state utility values for LOPD in the United Kingdom. Methods: Vignettes were developed for 7 health states of LOPD with states defined in terms of mobility and/or ventilatory support. Vignettes were drafted based on patient-reported outcome data from the Phase 3 PROPEL trial (NCT03729362) and supplemented by a literature review. Qualitative interviews with individuals living with LOPD and clinical experts were conducted to explore the health-related quality-of-life (HRQoL) impact of LOPD and to review the draft vignettes. Vignettes were finalized following a second round of interviews with individuals living with LOPD and used in health state valuation exercises with people of the UK population. Participants rated the health states using the EQ-5D-5L, visual analogue scale, and time trade-off interviews. Results: Twelve individuals living with LOPD and 2 clinical experts were interviewed. Following the interviews, 4 new statements were added regarding dependence on others, bladder control problems, balance issues/fear of falling, and frustration. One hundred interviews with a representative UK population sample were completed. Mean time trade-off utilities ranged from 0.754 (SD = 0.31) (no support) to 0.132 (SD = 0.50) (invasive ventilatory and mobility support-dependent). Similarly, EQ-5D-5L utilities ranged from 0.608 (SD = 0.12) to -0.078 (SD = 0.22). Discussion: The utilities obtained in the study are consistent with utilities reported in the literature (0.670-0.853 for nonsupport state). The vignette content was based on robust quantitative and qualitative evidence and captured the main HRQoL impacts of LOPD. The general public rated the health states consistently lower with increasing disease progression. There was greater uncertainty around utility estimates for the severe states, suggesting that participants found it harder to rate them. Conclusion: This study provides utility estimates for LOPD that can be used in economic modeling of treatments for LOPD. Our findings highlight the high disease burden of LOPD and reinforce the societal value of slowing disease progression.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Health-related quality of life in health states corresponding to different stages of perianal fistula associated with Crohn's disease: a quantitative evaluation of patients and non-patients in Japan

BACKGROUND

Perianal fistula (PF), a complication of Crohn's disease (CD), affects health-related quality of life (QOL).

OBJECTIVE

To elucidate QOL of health states corresponding to different stages of PF associated with CD in Japan.

METHOD

This cross-sectional, observational, web-based questionnaire survey assessed eight different health states in patients with CD and PF and individuals without CD (non-patients) from the Medilead Healthcare Panel (MHP) and determined the utility values (QOL scores) in each health state by the time trade-off method. In patients, we determined also the utility value of the current health state associated with CD and the PF. The analysis excluded respondents with logical inconsistencies.

RESULTS

The analysis included 82 patients and 576 non-patients with the same sex and age distribution as the Japanese population. In both groups, mean utility values were higher in remission (patients, 0.78; non-patients, 0.51) than in non-remission states, with lowest values for poor prognosis after proctectomy (patients, 0.13; non-patients, -0.10) and highest values for the state with mild symptoms (patients, 0.60; non-patients, 0.30). In patients, the mean utility value of the current health state was 0.71.

CONCLUSION

QOL decreases with increasing severity of PF and is lower for good prognosis after proctostomy than for remission.

Estimating health state utilities in primary hyperoxaluria type 1: a valuation study

AIMS

Quantitative data on health state utilities in primary hyperoxaluria type 1 (PH1) are lacking. This study was conducted to estimate utility values in PH1 using 3 standard valuation techniques.

MATERIALS AND METHODS

Health state vignettes were developed with input from expert clinicians to describe different stages of chronic kidney disease (CKD) within the setting of PH1, along with a post-combined liver and kidney transplant (CLKT) health state ≥12 months following transplantation. The utility associated with living in each PH1 health state, as described by the vignettes, was evaluated by members of the UK general public using standard utility assessment techniques, including EQ-5D-5L, Visual Analog Scale, and Time Trade-Off.

RESULTS

A similar pattern across the three valuation methods was observed. Utility values were roughly constant from CKD stage 1-3b and then dropped sharply from these states to CKD stage 4. Decreases in utility in the later stages of CKD (stages 4-5) were followed by a recovery in quality of life in the post-CLKT health state.

LIMITATIONS

Vignettes may not fully capture the burden of living with PH1.

CONCLUSIONS

This study serves as an informative source of data on how the burden of PH1 varies across disease stages of CKD and post-CLKT in patients with PH1. The study findings highlight the unique clinical features of PH1 compared with non-PH1-related CKD, such as the need for earlier and more intensive hemodialysis, the risk of systemic oxalosis, and the potential need for CLKT (as opposed to kidney-only transplant). The impact of PH1 on health-related quality of life, which worsens once hemodialysis is required and systemic disease manifestations occur, is captured in this study using quantitative health state utilities. These data provide an understanding of the impact of PH1 on health-related quality of life and will facilitate health economic evaluation of future treatments.

Willingness to Pay and Time Trade-off in Thai Patients with Port-Wine Stains

Background

Port-wine stains are congenital vascular abnormalities that impact children’s and parents’ quality of life (QoL). There are currently no established criteria for assessing the quality of life in PWS patients. Utility measures such as willingness-to-pay (WTP) and time trade-off (TTO) can be used to quantify disease burden, impact on QoL, and assess the cost-effectiveness of interventions.

Methods

This was a cross-sectional questionnaire-based survey study in Thailand from July 2021 to April 2022. The questionnaire included sociodemographic data and preference-based measurement, WTP and TTO. The primary outcome was a WTP and TTO for PWS laser treatment. The subsample analysis for the primary outcome was based on gender (male and female) and age (<5 years and ≥5 years). The household income was measured for time trade-off outcome.

Results

Out of 46 respondents, WTP for the base case at 40% improvement cost 6109.01 baht per visit. Patients were willing to spend their time 9.95 hours per visit for a clinical improvement of 40%. Female was willing to pay and spend more time than male, while those aged≥5 years were willing to pay and spend more time than those aged <5 years. High household income >100k per month willing to spend less time than lower income groups.

Conclusion

There were obvious correlations between WTP and TTO with clinical outcomes. Utility indicators such as WTP and TTO can be used to measure disease burden, impact on QoL, and assess the cost-effectiveness of interventions. WTP and TTO could provide a more personalized approach to improving QoL, considering each patient’s unique treatment plan and priority. This could help with patient uncertainty and long-term planning strategies to increase the QoL cost-effectively.

Correcting for discounting and loss aversion in composite time trade-off

Time trade-off utilities have been suggested to be biased upwards. This bias is a result of the method being applied assuming linear utility of life duration, which is violated when individuals discount future life years or are loss averse for health. Applying a "corrective approach", that is, measuring individuals' discount function and loss aversion and correcting time trade-off utilities for these individual characteristics, may reduce this bias in utilities. Earlier work has developed this approach for time trade-off in a student sample. In this study, the corrective approach was extended to composite time trade-off (cTTO) methodology, which enabled correcting utilities for health states worse than dead. In digital interviews a sample of 150 members of the general public completed cTTO tasks for six health states, and afterward they completed measurements of loss aversion and discounting. cTTO utilities were corrected using these measurements under multiple specifications. Respondents were also asked to reflect on and adjust their cTTO utilities directly. Our results show considerable loss aversion and both positive and negative discounting were prevalent. As predicted, correction generally resulted in lower utilities. This was in accordance with the direction of adjustments made by respondents themselves.

Exploration of the Reasons Why Health State Valuation Differs for Children Compared With Adults: A Mixed Methods Approach

OBJECTIVES

Evidence comparing utilities for adults and children consistently report higher utility values for child health states. This study investigates the reasons why child health states are valued differently.

METHODS

A total of 80 respondents (United Kingdom, Belgium, The Netherlands) participated in 1.5-hour face-to-face interviews. Respondents valued 4 health states from 2 perspectives (8-year-old child, 40-year-old adult) using visual analog scale and time trade-off. A total of 32 respondents participated in think-aloud interviews. Audio recordings were analyzed by 2 independent coders using NVIVO software. Statements, nodes, and themes were reviewed cyclically until consensus was reached.

RESULTS

Qualitative results: a total of 5 themes were identified in the data regarding child and adult valuation-intergenerational responsibility and dependency (childhood is crucial for forming life skills based on new experiences; adulthood is an important time to take care of the family), staying alive is important (life is worth living even with impaired health-related quality of life (HRQoL), for children and adults), awareness of poor HRQoL and ability to make decisions (children have difficulties comprehending poor HRQoL and their parents make their healthcare decision; adults can assess their own HRQoL and decide for themselves), coping ability (children are flexible and resilient; adults have experience with dealing with difficulties), and practical organization of care (children are cared for by their parents; adults are able to organize and pay for care). Mixed methods: comparing qualitative statements with respondents' higher utilities for child health states confirmed concordance between results.

CONCLUSIONS

Quality-adjusted life-years are interpreted differently for children and adults. Child-specific value sets are needed to reflect society's preferences and to adequately conduct health technology assessment of pediatric treatments.

Exploration of the Reasons Why Health State Valuation Differs for Children Compared With Adults: A Mixed Methods Approach

OBJECTIVES

Evidence comparing utilities for adults and children consistently report higher utility values for child health states. This study investigates the reasons why child health states are valued differently.

METHODS

A total of 80 respondents (United Kingdom, Belgium, The Netherlands) participated in 1.5-hour face-to-face interviews. Respondents valued 4 health states from 2 perspectives (8-year-old child, 40-year-old adult) using visual analog scale and time trade-off. A total of 32 respondents participated in think-aloud interviews. Audio recordings were analyzed by 2 independent coders using NVIVO software. Statements, nodes, and themes were reviewed cyclically until consensus was reached.

RESULTS

Qualitative results: a total of 5 themes were identified in the data regarding child and adult valuation-intergenerational responsibility and dependency (childhood is crucial for forming life skills based on new experiences; adulthood is an important time to take care of the family), staying alive is important (life is worth living even with impaired health-related quality of life (HRQoL), for children and adults), awareness of poor HRQoL and ability to make decisions (children have difficulties comprehending poor HRQoL and their parents make their healthcare decision; adults can assess their own HRQoL and decide for themselves), coping ability (children are flexible and resilient; adults have experience with dealing with difficulties), and practical organization of care (children are cared for by their parents; adults are able to organize and pay for care). Mixed methods: comparing qualitative statements with respondents' higher utilities for child health states confirmed concordance between results.

CONCLUSIONS

Quality-adjusted life-years are interpreted differently for children and adults. Child-specific value sets are needed to reflect society's preferences and to adequately conduct health technology assessment of pediatric treatments.

Trade-Offs among Sensing, Reporting, and Transmission in Cooperative CRNs

Cooperative spectrum sensing (CSS) has been verified as an effective approach to improve the sensing performances of cognitive radio networks (CRNs). Compared with existing works that commonly consider fusion with fixed inputs and neglect the duration of the reporting period in the design, we novelly investigate a fundamental trade-off among three periods of CSS: sensing, reporting, and transmission periods, and evaluate the impact of the fusion rule with a varying number of local sensing results. To be specific, the sensing time could be traded for additional mini-slots to report more local sensing results for fusion, or it could be traded for longer transmission time. In the CRNs with a given durations of sensing/reporting/transmission periods, we, respectively, formulate the throughput and collision probability and optimize the throughput under the collision constraint. The theoretical results show that, in the specific value intervals of the sensing parameters, the collision constraint provides an upper bound of the number of mini-slots in the reporting period or a lower bound of the sensing duration. We provide the approach to the maximum throughput in some cases.Finally, numerical results are presented to validate theoretical results.

Expect Nothing: The (Lack of) Influence of Subjective Life Expectancy on Valuation of Child Health States

Objective

Earlier research has shown that individuals' subjective life expectancy (SLE) affects health state valuation with time trade-off (TTO). Individuals with longer expected life durations are less willing to trade-off life duration, which yields higher utilities. In this article, the influence of SLE is explored in the valuation of EQ-5D-Y-3L with a proxy perspective, i.e., adults' valuation of health states considering the life of a 10-year-old child. As SLE for children is likely higher, this might explain earlier findings suggesting that individuals are less willing to trade-off years of life for children than for adults.

Methods

A total of 197 respondents were recruited to take part in digital TTO interviews, facilitated by trained interviewers. TTO interviews were implemented in accordance with the recommended protocol for the valuation of EQ-5D-Y-3L. Respondents valued 10 EQ-5D-Y-3L health states for a 10-year-old child, after which they were asked to report how old they themselves expected to become and also how old they expected a 10-year-old child to become.

Results

Generally, adult respondents reported higher SLE for children than for themselves. Neither SLE was systematically associated with the willingness to trade lifetime or the number of life years traded off in TTO tasks. This null-result was substantiated by regression analyses per health state.

Conclusion

The results of this study suggest that individuals' expectations about longevity are not associated with EQ-5D-Y-3L valuation. This lack of association is in contrast to earlier work and might be explained by the psychological distance introduced with proxy perspective valuation, or by the methodological differences with earlier work.

Utilities associated with stoma-related complications: peristomal skin complications and leakages

AIM

Peristomal skin complications (PSCs) and leakages are major issues for people living with a stoma. The purpose of this study is to understand how these stoma-linked complications impact health-related quality of life (HRQoL) in a UK population.

MATERIALS AND METHODS

The study used time trade-off (TTO) methodology to quantify health state utilities associated with two stoma-related complications: PSC and leakages. Respondents assessed 10 different health states with different PSC severity levels (no, mild, moderate or severe PSC) and frequencies of leakage events (2, 12 or 48 leakages onto clothes per year, and no leakage due to a digital solution). The average disutility value for each health state was also assessed. The study was conducted via a web-based survey in the UK adult general population.

RESULTS AND LIMITATIONS

The analysis included 758 respondents. Respondents considered living with a stoma with no PSC to be more favorable than the other health states. Severe pain, itching and/or burning (PIB) was associated with the largest disutility compared to no PSC. The disutility (0-1 scale) compared to no PSC was 0.287 (p < .0001), 0.106 (p < .0001) and 0.025 (p=.0005) for PIB scores of 8, 5 and 2, respectively, on a 1-10 scale. More frequent leakage events were associated with lower utility. The utility decreases compared to no PSC were 0.114 (p < .0001), 0.057 (p < .0001) and 0.022 (p < .0001) for 48, 12 and 2 leakage events per year, respectively. The health state with a digital notification solution that notifies the user before a leakage event happens was considered as good as no PSC.

CONCLUSIONS

Experiencing mild, moderate, and severe levels of PSC or leakage onto clothes is associated with a significant reduction in HRQoL compared to no PSC and/or no leakage. Stoma appliances that reduce the skin complications or keep leakage from reaching the clothes are likely to improve HRQoL.

Health state utilities associated with weight loss in type 2 diabetes and obesity

INTRODUCTION

Health state utilities associated with weight change are needed as inputs for cost-utility analyses (CUAs) examining the value of treatments for obesity and type 2 diabetes (T2D). Although some pharmaceutical treatments currently in development are associated with substantial weight loss, little is known about the utility impact of weight decreases greater than 10%. The purpose of this study was to estimate utilities associated with body weight decreases up to 20% based on preferences of individuals with obesity, with and without T2D.

METHODS

Health state vignettes were developed to represent respondents' own current weight and weight decreases of 2.5, 5, 10, 15, and 20%. Health state utilities were elicited in time trade-off interviews in two UK locations (Edinburgh and London) with a sample of participants with obesity, with and without T2D. Mean utility increases associated with each amount of weight decrease were calculated. Regression analyses were performed to derive a method for estimating utility change associated with weight decreases.

RESULTS

Analyses were conducted with data from 405 individuals with obesity (202 with T2D, 203 without T2D). Utility increases associated with various levels of weight decrease ranged from 0.011 to 0.060 in the subgroup with T2D and 0.015 to 0.077 in the subgroup without T2D. All regression models found that the percentage of weight decrease was a highly significant predictor of change in utility (p < .0001). The relationship between weight change and utility change did not appear to be linear. Equations are recommended for estimating utility change based on the natural logarithm of percentage of weight decrease.

DISCUSSION

Results of this study may be used to provide inputs for CUAs examining and comparing the value of treatments that are associated with substantial amounts of weight loss in patients with obesity, with or without T2D.

Eliciting Health State Utilities for Aromatic L-Amino Acid Decarboxylase (AADC) Deficiency: A Vignette Study in France

PURPOSE

Health-related quality of life (HRQoL) is difficult to measure in rare diseases, especially in paediatric populations, yet capturing HRQoL is critical to evaluating treatment, including the cost-effectiveness of treatments. Given the ultra-rare nature of AADC deficiency indirect elicitation of HRQoL data through proxy caregiver/parent ratings is not feasible. In these circumstances, HRQoL data may be derived through vignette studies using the general population. The aim of the study was to generate health utility values specific for France for AADC deficiency using vignettes.

METHODS

The study was completed online by panel participants from a French representative sample. Five health state vignettes, reflecting key milestones in the eladocagene exuparvovec clinical trials and economic model, were presented to the participants: "bedridden", "head control", "sitting unsupported", "standing with assistance" and "walking with assistance". The vignettes had been previously developed with input from parents of patients with AADC deficiency, patients and expert opinion. Participants also completed the Health Utilities Index-3 for the "bedridden" health state.

RESULTS

A total of 1001 participants (51% females; mean age 46 years) completed the vignettes. Utilities increased linearly as the health state improved for both the time trade-off (TTO): 0.47 (standard deviation, SD 0.36) to 0.54 (SD 0.36) and standard gamble (SG): 0.61 (SD 0.29) to 0.67 (SD 0.27). A significant minority had incongruent responses (high utilities for the bedridden compared to walking health states) for the vignette (27%). When these were removed, the TTO health utilities (N=729) ranged from 0.39 (SD 0.36) to 0.56 (SD 0.38) and 0.61 (SD 0.30) to 0.69 (SD 0.27) for the SG.

CONCLUSION

Health utilities were derived for AADC deficiency which will be used for a cost-effectiveness model of an AADC deficiency treatment.

Estimating an EQ-5D-3L Value Set for Romania Using Time Trade-Off

Objective: To provide health-related quality of life (HRQoL) data to support health technology assessment (HTA) and reimbursement decisions in Romania, by developing a country-specific value set for the EQ-5D-3L questionnaire. Methods: We used the cTTO method to elicit health state values using a computer-assisted personal interviewing approach. Interviews were standardized following the most recent version of the EQ-VT protocol developed by the EuroQoL Foundation. Thirty EQ-5D-3L health states were randomly assigned to respondents in blocks of three. Econometric modeling was used to estimate values for all 243 states described by the EQ-5D-3L. Results: Data from 1556 non-institutionalized adults aged 18 years and older, selected from a national representative sample, were used to build the value set. All tested models were logically consistent; the final model chosen to generate the value set was an interval regression model. The predicted EQ-5D-3L values ranged from 0.969 to 0.399, and the relative importance of EQ-5D-3L dimensions was in the following order: mobility, pain/discomfort, self-care, anxiety/depression, and usual activities. Conclusions: These results can support reimbursement decisions and allow regional cross-country comparisons between health technologies. This study lays a stepping stone in the development of a health technology assessment process more driven by locally relevant data in Romania.

Vignette-Based Utilities: Usefulness, Limitations, and Methodological Recommendations

Health technology assessment agencies often prefer that utilities used to calculate quality-adjusted life years in cost-utility analyses (CUAs) are derived using standardized methods, such as generic preference-based measures completed by patients in clinical trials. However, there are situations when no standardized approach is feasible or appropriate for a specific medical condition or treatment that must be represented in a CUA. When this occurs, vignette-based methods are often used to estimate utilities. A vignette (sometimes called a "scenario," "health state description," "health state vignette," or "health state") is a description of a health state that is valued in a preference elicitation task to obtain a utility estimate. This method is sometimes the only feasible way to estimate utilities representing a concept that is important for a CUA. Consequently, vignette-based studies continue to be conducted and published, with the resulting utilities used in economic models to inform decision making about healthcare resource allocation. Despite the potential impact of vignette-based utilities on medical decision making, there is no published guidance or review of this methodology. This article provides recommendations for researchers, health technology assessment reviewers, and policymakers who may be deciding whether to use vignette-based methods, designing a vignette study, using vignette-based utilities in a CUA, or evaluating a CUA that includes vignette-based utilities. Recommendations are provided on: (A) when to use vignette-based utilities, (B) methods for developing vignettes, (C) valuing vignettes, (D) use of vignette-based utilities in models, and (E) limitations of vignette methods.

Health utility measurement by time trade-off method in Hungary

Összefoglaló. Bevezetés: Az időalku (time trade-off) egy nemzetközileg széles körben alkalmazott életminőség- és egészséghasznosság-mérési módszer. Az időalkuval mért hasznosságértékek az egészségügyi technológiák költséghatékonysági vizsgálatakor az életminőséggel korrigált életév (quality-adjusted life year, QALY) mutatószám számítására használhatók. Kevés ismerettel rendelkezünk arról, hogy Magyarországon milyen betegségekben állnak rendelkezésre időalkuval mért hasznosságértékek. Célkitűzés: Célunk szisztematikus irodalmi áttekintés keretében összefoglalni és katalogizálni az időalku módszerrel mért hasznosságértékeket közlő publikációkat Magyarországon. Módszer: 2020 januárjában szisztematikus folyóirat-keresést végeztünk a PubMed, Web of Science és Matarka elektronikus adatbázisokban. Beválogatási kritériumaink a következők voltak: (1) eredeti közlemények, melyek (2) időalku módszerrel mértek hasznosságértéket, és (3) magyarországi mintán mért adatokat közöltek. Eredmények: 9 eredeti közleményt válogattunk be, amelyek összesen 7 krónikus betegségben (Crohn-betegség, időskori maculadegeneratio, krónikus migrén, pemphigus, psoriasis, primer dysmenorrhoea és rheumatoid arthritis) 23 egészségi állapot hasznosságát határozták meg. A kutatások mintanagysága 108 és 1996 fő között alakult. Két kutatás betegcsoportokat vizsgált, kettő az általános populációt, és három vizsgálatban szerepelt mindkettő. Hat kutatás használta a hagyományos időalku valamelyik formáját, egy pedig az összetett időalku módszert. Egy kutatásban szerepelt 'rosszabb a halálnál' válaszlehetőség. A leggyakrabban alkalmazott időtáv a standard 10 év volt (71%). Az egyes állapotok hasznosságának átlaga 0,34 (kezeletlen pemphigus vulgaris) és 0,94 (enyhe primer dysmenorrhoea) között változott. A 'non-traderek' aránya az egyes kutatásokban 0 és 29% között változott. Következtetések: Egyre több krónikus betegségben elérhetők a magyar társadalom vagy betegek preferenciáin alapuló egészséghasznosság-értékek. A hazai időalku-vizsgálatok többsége megfelel a nemzetközi minőségi követelményeknek. Az időalku módszer alkalmazása javasolt más krónikus állapotokban is, a felmért hasznosságértékek segíthetik az egészségügyi technológiákkal kapcsolatos finanszírozói döntéshozatalt. Orv Hetil. 2021; 162(14): 542-554.

SUMMARY

INTRODUCTION

Time trade-off (TTO) is a widely used method to assess health-related quality of life and health utilities for economic evaluations of health technologies. Little is known about the use of TTO in the Hungarian context.

OBJECTIVE

To systematically summarize the existing literature on the method in Hungary.

METHOD

In January 2020, we conducted a systematic literature search in three electronic databases (MEDLINE, Web of Science and the Hungarian Periodicals Table of Contents Database). Our inclusion criteria were: (1) original publications, which (2) measured utilities by using TTO, (3) from a Hungarian sample.

RESULTS

Nine publications containing seven original studies were included that reported utilities for 23 different health states in seven chronic diseases (age-related macular degeneration, chronic migraine, Crohn's disease, pemphigus, primary dysmenorrhoea, psoriasis and rheumatoid arthritis). Sample sizes ranged from 108 to 1996 respondents. Two studies used general population samples, another two used patient groups and three studies used both. Six studies used a form of conventional TTO and one used composite TTO method. The most frequent timeframe was 10 years (71%). The lowest mean utility was 0.34 (uncontrolled pemphigus vulgaris), while the highest was 0.94 (mild primary dysmenorrhoea). The overall proportion of non-traders ranged between 0 and 29% across studies.

CONCLUSIONS

A growing number of studies are using TTO to assess utilities for chronic conditions from the general population or patients in Hungary. The majority of Hungarian TTO studies have met international quality standards. The assessment of TTO utilities is recommended also in other chronic conditions to assist health technology assessment. Orv Hetil. 2021; 162(14): 542-554.

Patients' preferences for delaying metastatic castration-resistant prostate cancer: Combining health state and treatment valuation

PURPOSE

Men with castration-resistant prostate cancer (CRPC) experience disease progression at different rates. The purpose of this study was to quantify the strength of patient preferences for delaying prostate cancer progression utilizing a discrete choice experiment (DCE) and valuing 3 health states in the continuum of CRPC.

PATIENTS AND METHODS

Men with CRPC, recruited from US patient panels, completed a cross-sectional web-based survey. The survey consisted of vignette-based time trade-off and a DCE designed to quantify patients' willingness to pay to delay metastatic CRPC. Three health states were presented: (1) living with non-metastatic castration-resistant prostate cancer (nmCRPC) (2) living with metastatic CRPC (mCRPC) before chemotherapy, and (3) living with mCRPC either on or after chemotherapy. The DCE consisted of 15 hypothetical choices with attributes characterizing CRPC (pain, fatigue, out of pocket cost, dosing, and time until cancer metastasizes). Patients' willingness to pay for changes in each attribute were derived.

RESULTS

A total of 176 patients with CRPC were surveyed (mean age: 64.2 years; 74% nmCRPC). Patients valued the nmCRPC health state (0.865) significantly higher than mCRPC before chemotherapy (0.743) or mCRPC on or after chemotherapy (0.476), both P < 0.001. In the DCE, patient treatment valuation was most affected by increasing the number of months until cancer metastasized; patients were willing to pay an additional $682 per month to delay time to metastases from 6 to 24 months (95% Confidence Interval: $387-$977) and additional $1,041 per month to delay time to metastasis to 48 months (95% Confidence Interval: $591-$1,490).

CONCLUSIONS

The results of this study demonstrated men with CRPC place significant value on delaying metastases. This study represents the first time 2 stated preference methods, time trade-off and DCE, were used together to understand patients' preferences and valuation of health states in CRPC.

Testing the "Nonstopping" Time Trade-Off: Is It Better Than the Composite Time Trade-Off?

OBJECTIVES

There are several issues of concern for the composite time trade-off (c-TTO) used to estimate EQ-5D-5L value sets. The "nonstopping" TTO (n-TTO) differs from the c-TTO mainly in 2 aspects: (1) n-TTO uses a standardized top-down or bottom-up routing; and (2) n-TTO continues when indifference is indicated by respondents. In this study, we aimed to test the feasibility of n-TTO and compared it with c-TTO.

METHODS

The study was conducted in parallel in Norway and Singapore. In both countries, members of the general population were invited to complete 10 n-TTO or c-TTO tasks. Acceptability and feasibility of n-TTO were assessed using respondents' feedback, administration time, and valuation success rate. Characteristics of the TTO data derived from c-TTO and n-TTO tasks were examined at task, individual, as well as group levels.

RESULTS

In both Norway and Singapore, the success rate of n-TTO tasks was high (> 95%) and the n-TTO tasks took less time to complete than the c-TTO tasks, and there were fewer or smaller "spikes" in the distributions of n-TTO data compared to c-TTO data. In Norway, the individual-level n-TTO and c-TTO data had similar distribution and logical consistency profiles. In Singapore, n-TTO was inferior to c-TTO in logical consistency; however, a similar degree of nonmonotonicity was observed in modeling of n-TTO and c-TTO data.

CONCLUSIONS

The noniterative n-TTO appeared to be feasible and may generate data with better distribution in shorter time than c-TTO. Further research is needed to assess this new health-state valuation method.

What is it going to be, TTO or SG? A direct test of the validity of health state valuation

Standard gamble (SG) typically yields higher health state valuations than time trade-off (TTO), which may be caused by biases affecting both methods. It has been suggested that TTO yields more accurate health state valuations, because TTO is subject to both upward and downward biases that may cancel out. Verifying this claim, however, would require a golden standard to test validity against. In this study, we attempted to provide a first direct test of the validity of health state valuation. A total of 119 students completed five TTO and SG tasks. Afterwards, their health state valuations elicited with TTO and SG were shown to them in an interactive graph. Respondents were asked to indicate which of the methods represented their valuation of a health state best. They could also adjust their valuation. Overall, we found that respondents indicated that TTO valuations better reflected health state valuations, a result that was more pronounced for more severe health states. When offered the opportunity, on average, respondents adjusted health state valuations downwards. These findings may have implications for future work on (bias correction in) health state valuations.

Do Discrete Choice Experiments Approaches Perform Better Than Time Trade-Off in Eliciting Health State Utilities? Evidence From SF-6Dv2 in China

OBJECTIVES

To explore the acceptability, consistency, and accuracy of eliciting health state utility values using discrete choice experiment (DCE) and DCE with life duration dimension (DCE_TTO) as compared with conventional time trade-off (TTO) by using the SF-6Dv2.

METHODS

During face-to-face interviews, a representative sample of the general population in Tianjin, China, completed 8 TTO tasks and 10 DCE/DCE_TTO tasks, with the order of TTO and DCE/DCE_TTO being randomized. The fixed-effect model and conditional logit models were used for TTO and DCEs data estimation, respectively. Acceptability was assessed by self-reported difficulties in understanding/answering. Consistency was observed by the monotonicity of model coefficients. Accuracy was evaluated by investigating differences between observed and predicted TTO values using intraclass correlation coefficient, mean absolute difference, and root mean square difference.

RESULTS

A total of 503 respondents (53.7% male; range, 18-86 years) were included, with comparable characteristics between respondents who completed DCE (N = 252) and DCE_TTO (N = 251). No significant difference was observed in self-reported difficulties among 3 approaches. The monotonicity of coefficients could not be achieved for 2 DCE approaches, even when combining the inconsistent levels. The health state utility values generated by DCE were generally higher than those generated by TTO, whereas DCE_TTO was lower than TTO. The TTO had a better prediction accuracy than the DCEs.

CONCLUSIONS

Two DCE approaches are feasible for eliciting health state utility values; however, they are not considered to be easier to understand/answer than TTO. There are systematic differences in the health state utility values generated by 3 approaches. The issue of non-monotonicity from 2 DCE approaches remains a concern.

Creating a Health Utility Value for Birdshot Chorioretinopathy

PURPOSE

To create a health utility value for birdshot chorioretinopathy (BCR) using Time Trade-Off (TTO) and Standard Gamble (SG) utilities.

METHOD

Adult BCR patients completed TTO, SG, EQ-5D-5L, and NEI VFQ-25 questionnaires and underwent a detailed history and clinical examination.

RESULTS

A total of 28 BCR patients (9 M, 19 F; mean age 62 years, range 47-83) were included. There were 22 patients with a logMAR vision of 0.3 or better in both eyes. Mean TTO was 0.90 ± SD 0.18 (range 0.33-1.0) and mean SG was 0.94 ± SD 0.14 (range 0.5-1.0). TTO correlated with EQ-5D-5L index value (p = .024) and NEI VFQ-25 composite score (p = .015).

CONCLUSIONS

Of 28 patients with BCR, 11 would trade remaining life (mean 5.4 years), and 6 would take a risk of immediate death (mean 28% risk), in return for perfect vision in both eyes for the rest of their life.

Estimating health state utilities associated with a rare disease: familial chylomicronemia syndrome (FCS)

Aims: Familial chylomicronemia syndrome (FCS) is a rare genetic disorder with no currently approved therapies. Treatments are in development, and cost-utility analyses will be needed to examine their value. These models will require health state utilities representing FCS. Therefore, the purpose of this study was to estimate utilities for FCS and an associated episode of acute pancreatitis (AP).Methods: Because it is not feasible to gather a large enough sample of patients with this extremely rare condition to complete standardized preference-based measures, vignette-based methods were used to estimate utilities. In time trade-off interviews, general population participants in the UK and Canada valued health state vignettes drafted based on literature review, clinician input, and interviews with patients. Four health states described variations of FCS. A fifth health state, describing AP, was added to one of the other health states to evaluate its impact on utility.Results: A total of 308 participants provided utility data (208 UK; 100 Canada). Mean utilities for FCS health states ranged from 0.46 to 0.83, with higher triglycerides, more severe symptoms, and a history of AP associated with lower utility values. The disutility (i.e. utility decrease) of AP ranged from -0.17 to -0.25, with variations depending on the health state to which it was added. Utility means were similar in the UK and Canada.Conclusions: The vignette-based approach is useful for estimating utilities of a rare disease. The health state utilities derived in this study would be useful in models examining cost-effectiveness of treatments for FCS.

Using Both Time Tradeoff and Discrete Choice Experiments in Valuing the EQ-5D: Impact of Model Misspecification on Value Sets

Introduction. The EQ-5D-5L valuation protocol contains both time tradeoff (TTO) tasks and discrete choice experiments (DCE), raising the question of how to best use these in creating a value set. The hybrid model, which combines TTO and DCE data, has emerged as a commonly used approach. However, this model assumes independence among responses from the same individual, a linear relationship between TTO and DCE utilities, and, in many implementations, homoscedastic residuals. The aims of this study are to examine alternatives to these assumptions and determine the impact of misspecification on value sets. Methods. We performed a simulation study, parameterized using the US EQ-5D-5L valuation study, to assess the impact of model misspecification. We simulated TTO and DCE data with nonlinear relationships between TTO and DCE utilities, heteroscedastic errors, and correlated responses. Simulated data were analyzed using hybrid models with and without heteroscedasticity, Tobit models with and without heteroscedasticity, a latent class model, and a mixed model. Results. Mean absolute errors (MAEs) for correctly specified models were <0.05, whereas models that incorrectly assumed a linear relationship between TTO and DCE utilities or homoscedasticity of TTO responses featured states with an MAE >0.1. When a linear relationship between TTO and DCE utilities held, using both TTO and DCE data under correct specification yielded smaller MAEs compared with using TTO data alone but yielded larger MAEs when a linear relationship did not hold. Mistakenly assuming homoscedasticity led to increased MAEs, whereas ignoring dependence did not. Conclusions. Because heteroscedasticity in TTO utilities and nonlinear associations between DCE and TTO utilities have been noted, we recommend careful assessment of scedasticity and linearity to ascertain the suitability of a hybrid model.

Health utility and quality of life in pediatric liver transplant recipients

To measure HU and HRQOL in pediatric liver transplant (LT) recipients, a cross-sectional study of patient-parent dyads was conducted. Direct HU were assessed in 48 adolescents ≥12 years using SG and TTO techniques. Indirect HU were measured by Health Utility Index 2 and HUI3 for subjects ≥12 years and CHU9D for ≥7 years. Patients reported HRQOL using PedsQL™ GC and PedsQL™ TM. A total of 108 dyads participated (55.6% female; 73.2% Caucasian; 42.6% biliary atresia; 35.2% living donor; 37.0% Medicaid). Mean age at survey was 13.6 ± 3.5 years, and time from LT was 8.9 ± 4.9 years. 61.2% were on monotherapy, 25 (23.2%) had acute rejection within 3 years, and 15 (13.9%) had a biliary obstruction within 5 years. Mean indirect HU and HRQOL scores by child report were lower than norms (P < .001). LRD recipients had higher PedsQL™ GC, PedsQL™ TM, and HUI3 scores (P < .01). HU in pediatric LT recipients are lower than norms. Availability of HU scores for post-transplant health states will enable measurement of quality-adjusted life years for future comparative effectiveness studies.

Preference for Alternate-Day Versus Conventional In-Center Dialysis: A Health Utility Elicitation

Background:

Mortality rates for patients on hemodialysis (HD) continue to be high, in particular, following the long interdialytic period, yet thrice-weekly conventional HD (CHD) is still an almost universal regimen. Alternate-day dialysis (ADD) may have advantages over the current schedule because it would eliminate the long interdialytic break. A preliminary, as yet unpublished, patient simulation and cost-utility analysis compared CHD versus ADD and demonstrated that the economic attractiveness of ADD was sensitive, in particular, to patients’ preference for ADD versus CHD. To date, this preference has not been elicited.

Objective:

To elicit utilities for both CHD and ADD using 3 standard elicitation methods among a prevalent cohort of patients on CHD.

Design:

This study is a single-center survey of patient preferences (utilities).

Setting:

This study took place within the dialysis units of Sunnybrook Health Centre, a university-affiliated teaching hospital in Toronto, Ontario, Canada, which encompasses 174 patients on in-center HD.

Patients:

Those older than 18 years of age, on thrice-weekly HD, were included in this study.

Measurements:

Descriptive statistics were used to summarize patient characteristics and the utility values generated. A multiple linear regression was performed to determine an association between participant characteristics and the utility ratio.

Methods:

Via standardized face-to-face interviews by a single investigator, 3 utility elicitation methods, visual analogue scale (VAS), time trade-off (TTO), and standard gamble (SG), were administered to generate utilities for each patient for their current health state of CHD (thrice-weekly). After completing this task, we provided each patient with a concise summary regarding the current literature on how ADD may impact their health. Finally, patients were asked to envision their health while on an ADD regimen while repeating the VAS, TTO, and SG.

Results:

We recruited 65 participants. The mean utilities of CHD versus ADD were similar for all 3 methods. Visual analogue scale, TTO, and SG had utility values of 0.6 ± 0.2, 0.6 ± 0.3, and 0.7 ± 0.3, and 0.6 ± 0.2, 0.7 ± 0.3, and 0.7 ± 0.3 for CHD and ADD, respectively. The ratio for CHD to ADD was 1.1 ± 0.4, 1.1 ± 0.5, and 1.0 ± 0.2 for VAS, TTO, and SG, respectively.

Limitations:

Small sample size from a single center, where not all participants agreed to participate, wide variability in participant responses and requiring patients to conceptually imagine life on ADD may have affected our results.

Conclusions:

Compared with CHD, there was no difference in the preference toward ADD which demonstrates promise that adopting an alternate-day schedule may be acceptable to patients. Furthermore, with the generation of a utility for ADD, this will allow for more precise estimates in future simulation studies of the economic attractiveness of ADD.

Trial registration:

Not required as this article is not a systematic review nor does it report the results of a health care intervention.

The EQ-5D-5L Value Set for England: Response to the "Quality Assurance"

OBJECTIVES

To respond to the 'quality assurance' of the EQ-5D-5L value set for England study.

METHODS

We provide a point-by-point response to the issues raised by the authors of the quality assurance paper, drawing on theoretical arguments, empirical analyses and practical considerations.

RESULTS

We provide evidence to show that many of the points made by the authors of the quality assurance are misleading, suggest misunderstandings, or are irrelevant.

CONCLUSIONS

The modeling approaches which were used appropriately address the characteristics of the data and provide a reasonable representation of the average stated preferences of general public in England. We provide reflections on the conduct of stated preference studies, and suggestions for the way forward.

Valuing Health State: An EQ-5D-5L Value Set for Ethiopians

OBJECTIVES

There is a growing interest in health technology assessment and economic evaluations in developing countries such as Ethiopia. The objective of this study was to derive an EQ-5D-5L value set from the Ethiopian general population to facilitate cost utility analysis.

METHODS

A nationally representative sample (N = 1050) was recruited using a stratified multistage quota sampling technique. Face-to-face, computer-assisted interviews using the EuroQol Portable Valuation Technology (EQ-PVT) protocol of composite time trade-off (c-TTO) and discrete choice experiments (DCEs) were undertaken to elicit preference scores. The feasibility of the EQ-PVT protocol was pilot tested in a sample of the population (n = 110). A hybrid regression model combining c-TTO and DCE data was used to estimate the final value set.

RESULTS

In the pilot study, the acceptability of the tasks was good, and there were no special concerns with undertaking the c-TTO and DCE tasks. The coefficients generated from a hybrid model were logically consistent. The predicted values for the EQ-5D-5L ranged from -0.718 to 1. Level 5 anxiety/depression had the largest impact on utility decrement (-0.458), whereas level 5 self-care had the least impact (-0.222). The maximum predicted value beyond full health was 0.974 for the 11112 health state.

CONCLUSIONS

This is the first EQ-5D-5L valuation study in Africa using international valuation methods (c-TTO and DCE) and also the first using the EQ-PVT protocol to derive a value set. We expect that the availability of this value set will facilitate health technology assessment and health-related quality-of-life research and inform policy decision making in Ethiopia.

Developing a preference-based utility scoring algorithm for the Psoriasis Area Severity Index (PASI)

Introduction: It is challenging to identify health state utilities associated with psoriasis because generic preference-based measures may not capture the impact of dermatological symptoms. The Psoriasis Area Severity Index (PASI) is one of the most commonly used psoriasis rating scales in clinical trials. The purpose of this study was to develop a utility scoring algorithm for the PASI. Methods: Forty health states were developed based on PASI scores of 40 clinical trial patients. Health states were valued in time trade-off interviews with UK general population participants. Regression models were conducted to crosswalk from PASI scores to utilities (e.g. OLS linear, random effects, mean, robust, spline, quadratic). Results: A total of 245 participants completed utility interviews (51.4% female; mean age = 45.3 years). Models predicting utility based on the four PASI location scores (head, upper limbs, trunk, lower limbs) had better fit/accuracy (e.g. R², mean absolute error [MAE]) than models using the PASI total score. Head/upper limb scores were more strongly associated with utility than trunk/lower limb. The recommended model is the OLS linear model based on the four PASI location scores (R² = 0.13; MAE = 0.03). An alternative is recommended for situations when it is necessary to estimate utility based on the PASI total score. Conclusions: The derived scoring algorithm may be used to estimate utilities based on PASI scores of any treatment group with psoriasis. Because the PASI is commonly used in psoriasis clinical trials, this scoring algorithm greatly expands options for quantifying treatment outcomes in cost-effectiveness analyses of psoriasis therapies. Results indicate that psoriasis of the head/upper limbs could be more important than trunk/lower limbs, suggesting reconsideration of the standard PASI scoring approach.

Patient preferences and health state utilities associated with dulaglutide and semaglutide injection devices among patients with type 2 diabetes in Italy

Aims: Several glucagon like peptide-1 (GLP-1) receptor agonists are available as weekly injections for treatment of type 2 diabetes. These medications vary in their injection devices, and these differences could impact quality-of-life and patient preference. The purpose of this study was to examine patient preferences and estimate health state utilities associated with injection devices for two weekly GLP-1 therapies. Materials and methods: Participants with type 2 diabetes in Italy (Milan, Rome) valued three health state vignettes in time trade-off interviews. The health states had identical descriptions of type 2 diabetes, but differed in description of the treatment process: (1) oral treatment regimen, (2) oral plus weekly dulaglutide injection, and (3) oral plus weekly semaglutide injection. Results: A total of 216 participants completed interviews (57.9% male; mean age = 60.5). Almost all patients (99.5%) preferred the oral health state over either injection health state. Comparing between the two injections, 88.4% preferred the dulaglutide health state, while 11.6% preferred the semaglutide state. Mean (SD) utilities were 0.907 (0.076) for oral, 0.894 (0.085) for dulaglutide, and 0.887 (0.087) for semaglutide. The mean (SD) utility difference between the injection device health states was 0.007 (0.019). Limitations: Although the health states were designed to match the injection device instructions for use as closely as possible, vignette-based methods are inherently limited because results are based on perceptions of the health states rather than actual patient experience with the devices. Conclusions: Results provide insight into patient preferences associated with injection devices for weekly GLP-1 receptor agonists. The majority of patients preferred the dulaglutide device over the semaglutide device, and for some patients, this difference had an impact on utility valuations. Patient preferences for injection devices could be an important factor to consider when selecting treatments for type 2 diabetes.

QALYs without bias? Nonparametric correction of time trade-off and standard gamble weights based on prospect theory

Common health state valuation methodologies, such as standard gamble (SG) and time trade-off (TTO), typically produce different weights for identical health states. We attempt to alleviate these differences by correcting the confounding influences modeled in prospect theory: loss aversion and probability weighting. Furthermore, we correct for nonlinear utility of life duration. In contrast to earlier attempts at correcting TTO and SG weights, we measure and correct all these tenets simultaneously, using newly developed nonparametric methodology. These corrections were applied to three less-than-perfect health states, measured with TTO and SG. We found considerable loss aversion and probability weighting for both gains and losses in life years, and we observe concave utility for gains and convex utility for losses in life years. After correction, the initially significant differences in weights between TTO and SG disappeared for all health states. Our findings suggest new opportunities to account for bias in health state valuations but also the need for further validation of resulting weights.

Valuing Health States in Russia: A First Feasibility Study

OBJECTIVE

The aim of this study was to explore the feasibility of different health-related quality-of-life valuation methods in a new setting. Based on a small feasibility study of 100 young Russians, we trialed different methodologies and identified key differences that have implications for the development of health technology assessment in Russia.

METHODS

In face-to-face interviews, respondents completed a series of health self-assessments based on a modified version of the EQ-5D-3L, visual analogue scale, time tradeoff, standard gamble, and best-worst scaling methodologies, covering actual and hypothetical health states.

RESULTS

We found that (1) the visual analogue scale produced lower health valuations and fewer logical inconsistencies than either time trade-off or standard gamble methodologies; (2) initial health states can be decisive in determining values assigned to health improvements; (3) respondents evaluate abstract health states more positively than their own actual health states; (4) there is evidence consistent with the hypothesis that actual and hypothetical health state valuation, using EQ-5D-3L, is an artifact of understanding rather than preference and that the incorporation of additional levels may therefore be no panacea if the dimensions themselves overlook important attributes; and (5) the country context is important in determining how respondents relate to the survey tools and how those survey tools are translated and delivered.

CONCLUSIONS

Russia is commencing its health technology assessment journey and should proceed cautiously as it moves toward the valuation of health benefits. These results suggest a useful framework for a more in-depth development of health valuation methodologies in Russia.

Health state utilities associated with treatment options for acute myeloid leukemia (AML)

Aims: Acute myeloid leukemia (AML) treatment typically involves remission induction chemotherapy followed by consolidation chemotherapy. New treatments for AML have recently been introduced, including a chemotherapy formulation called CPX-351, which is administered via less time-intensive IV infusion than the standard "7 + 3" continuous infusion regimen of cytarabine plus an anthracycline. The purpose of this study was to estimate utilities that could be used in economic modeling of AML treatment. Materials and methods: In time trade-off interviews, participants from the UK general population valued 12 health states drafted based on literature and clinician interviews. To identify disutility associated with chemotherapy, two types of induction and four types of consolidation were added to an otherwise identical health state describing AML. The decrease in utility when adding these chemotherapy regimens represents the disutility of each regimen. Five additional health states were valued to estimate utilities associated with other AML treatments. Results: Two hundred participants completed interviews. Mean (SD) utilities were 0.55 (0.31) for pre-treatment AML and 0.66 (0.29) for AML in temporary remission. Adding any chemotherapy significantly decreased utility (p < 0.0001). Induction had a mean disutility of -0.11 with CPX-351 and -0.15 with 7 + 3. Mean disutility for consolidation ranged from -0.03 with outpatient CPX-351 to -0.11 with inpatient 5 + 2. Utilities are also reported for other AML treatments (e.g. transplant, low-intensity chemotherapy). Limitations: One limitation is that the differences in adverse event profiles between the treatment regimens were based on clinician opinion. Future use of CPX-351 in clinical trials or clinical settings will provide additional information on its adverse event profile. Conclusions: While all chemotherapy regimens were associated with disutility, regimens with shorter hospitalization and less time-intensive infusion were generally perceived as preferable. These utilities may be useful in cost-utility models comparing the value of AML treatments.

Health state utility values of osteoporotic fractures among Korean women

Objectives: This study aimed to investigate health state utility values in eight health states related to osteoporosis and osteoporotic fractures using time trade-off (TTO) technique among postmenopausal Korean women.Methods: Scenarios describing eight health states including osteoporosis and hip, vertebral, post-hip, post-vertebral, ankle, humerus, and wrist fractures were developed and presented to 500 female participants aged 45 to 59 years who were selected with probability proportionate to age group and region for this investigation. Each health states valuation was derived using the trade-off (TTO) technique. Ten years of a given health state was traded off with a shorter length of time in full health.Results: Mean scores of each state were calculated. Osteoporosis scored the highest (0.669 ± 0.155), followed by wrist fracture (0.656 ± 0.151). Hip (0.298 ± 0.158) and vertebral (0.298 ± 0.160) fractures were found to be the worst health states. Post-hip (0.446 ± 0.159) and post-vertebral fractures (0.455 ± 0.160) were also considered undesirable states. All fractures were associated with disutilities, ranging from a mean of -0.013 to -0.371. These values were statistically significant (p < 0.0001). Hip and vertebral fractures are among the most serious consequences of osteoporotic fractures.Conclusions: The vertebral and hip fractures marked the lowest utility scores among post-menopausal women in Korea.

Valuation of Quality Weights for EuroQol 5-Dimensional Health States With the Time Trade-Off Method in the Capital of Iran

BACKGROUND

The EuroQol 5-dimension (EQ-5D) is a standard instrument that is widely used for measuring health-related quality of life and quality-adjusted life years in economic evaluation of healthcare interventions.

OBJECTIVE

To estimate a preference valuation set for EQ-5D 3-level (3L) health states from the perspective of the general population in the capital of Iran.

METHODS

Eight hundred seventy adults aged ≥18 years were interviewed in Tehran (Iran's capital) from July to November 2013. The participants were selected by a stratified random sampling method and were interviewed face-to-face at their usual residence. Forty-two health states were selected and valued from the 243 states derived from the EQ-5D-3L instrument. Each respondent valued 11 health states using the time trade-off method. Generalized least squares regression with random effect was used to predict values for health states.

RESULTS

The analysis was performed for 846 respondents. The final model yielded the best fit for the time trade-off value at the individual level with an overall R² of 0.45 and a mean absolute error of 0.214. The mean values for the 42 health states ranged from 0.934 for state 11121 to -0.142 for state 33333.

CONCLUSIONS

This study provided for the first time a value set for calculating quality-adjusted life years from the EQ-5D instrument in Iran. The Iranian EQ-5D-3L value set slightly differs from the value sets of the UK and the United States.