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

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

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

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

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

BACKGROUND: Face-to-face interviews are recommended for the collection of composite time trade-off (cTTO) data. The coronavirus disease 2019 (COVID-19) social distancing measures made researchers consider videoconferencing interviews as an alternative mode of administration, but little evidence about the implementation of videoconferencing in valuation studies is available. This study provides insights into the effect of videoconferencing on the quality of data, evaluating interviewers' and respondents' engagement level in videoconferences compared with face-to-face interviews. METHODS: We used cTTO data collected in Belgium and Spain following the EQ-5D-Y-3L valuation protocol. Due to the COVID-19 pandemic, both projects interrupted the face-to-face data collection before reaching the target sample. The remaining interviews were conducted by videoconference. We compared both modes of administration in terms of interviewers' engagement (task duration and number of moves in each example) and respondents' engagement (task duration and proportions of specific response values, in half-year units). To minimise interviewers' learning effects, we split our sample into three groups: (1) first 20 interviews conducted face-to-face; (2) subsequent interviews conducted face-to-face; and (3) videoconferencing interviews. RESULTS: The comparison between videoconferencing and subsequent face-to-face interviews showed the interviewer's engagement was not affected by the mode of administration as almost no significant results were found either in the task duration or the numbers of moves shown in the examples. Similarly, none of the respondents' task duration or proportion of specific responses or half-year units were affected by the mode of administration in either of the two countries. CONCLUSIONS: No evidence suggested that the quality of cTTO data is reduced when using videoconferencing compared with face-to-face interviews.

Cost-effectiveness analysis of the SAPIEN 3 transcatheter aortic valve implant in patients with symptomatic severe aortic stenosis.

INTRODUCTION AND OBJECTIVES: Transcatheter aortic valve implant has become a widely accepted treatment for inoperable patients with aortic stenosis and patients at high surgical risk. Its indications have recently been expanded to include patients at intermediate and low surgical risk. Our aim was to evaluate the efficiency of SAPIEN 3 vs conservative medical treatment (CMT) or surgical aortic valve replacement (SAVR) in symptomatic inoperable patients at high or intermediate risk. METHODS: We conducted a cost-effectiveness analysis of SAPIEN 3 vs SAVR/CMT, using a Markov model (monthly cycles) with 8 states defined by the New York Heart Association and a time horizon of 15 years, including major complications and management after hospital discharge, from the perspective of the National Health System. Effectiveness parameters were based on the PARTNER trials. Costs related to the procedure, hospitalization, complications, and follow-up were included (euros in 2019). An annual discount rate of 3% was applied to both costs and benefits. Deterministic and probabilistic sensitivity analyses (Monte Carlo) were performed. RESULTS: Compared with SAVR (high and intermediate risk) and CMT (inoperable), SAPIEN 3 showed better clinical results in the 3 populations and lower hospital stay. Incremental cost-utility ratios (€/quality-adjusted life years gained) were 5471 (high risk), 8119 (intermediate risk) and 9948 (inoperable), respectively. In the probabilistic analysis, SAPIEN 3 was cost-effective in more than 75% of the simulations in the 3 profiles. CONCLUSIONS: In our health system, SAPIEN 3 facilitates efficient management of severe aortic stenosis in inoperable and high- and intermediate-risk patients.

Cost-effectiveness of adding Sativex® spray to spasticity care in Belgium: using bootstrapping instead of Monte Carlo simulation for probabilistic sensitivity analyses.

BACKGROUND: Uncertainty in model-based cost-utility analyses is commonly assessed in a probabilistic sensitivity analysis. Model parameters are implemented as distributions and values are sampled from these distributions in a Monte Carlo simulation. Bootstrapping is an alternative method that requires fewer assumptions and incorporates correlations between model parameters. METHODS: A Markov model-based cost-utility analysis comparing oromucosal spray containing delta-9-tetrahidrocannabinol + cannabidiol (Sativex®, nabiximols) plus standard care versus standard spasticity care alone in the management of multiple sclerosis spasticity was performed over a 5-year time horizon from the Belgian healthcare payer perspective. The probabilistic sensitivity analysis was implemented using a bootstrap approach to ensure that the correlations present in the source clinical trial data were incorporated in the uncertainty estimates. RESULTS: Adding Sativex® spray to standard care was found to dominate standard spasticity care alone, with cost savings of €6,068 and a quality-adjusted life year gain of 0.145 per patient over the 5-year analysis. The probability of dominance increased from 29% in the first year to 94% in the fifth year, with the probability of QALY gains in excess of 99% for all years considered. CONCLUSIONS: Adding Sativex® spray to spasticity care was found to dominate standard spasticity care alone in the Belgian healthcare setting. This study showed the use of bootstrapping techniques in a Markov model probabilistic sensitivity analysis instead of Monte Carlo simulations. Bootstrapping avoided the need to make distributional assumptions and allowed the incorporation of correlating structures present in the original clinical trial data in the uncertainty assessment.