Advances in Measurement and Valuation of Tools to Inform Health and Social Care

This dissertation sought to examine new developments in the measurement and valuation of health and well-being, related to the development of more comprehensive descriptive systems and to the valuation of expanded descriptive systems, i.e., using “bolt-on” dimensions. The aim of the first study was to draw comparisons between the EQ-HWB-S and the EQ-5D-5L in term of content coverage and measurement properties. The second study examined the feasibility and acceptability of a new approach to valuing multi-dimensional measures when adding dimension(s) to an existing measure. The third study aimed to apply a new approach to valuing multi-dimensional measures, the SPP method, to value a bolt-on dimensions while retaining the scaling of the reference EQ-5D-5L value set. Specifically, the first study compared the recently developed EQ-HWB-S and a well-established and widely used MAUI, the EQ-5D-5L (Herdman et al., 2011). Content coverage and measurement properties were examined in terms of acceptability, response distributions, ceiling and floor effects, convergent validity, and the ability to discriminate between chronic health conditions, caregiving status, and caregiver burden. These results provide evidence on the validity of the EQ-HWB in large, heterogeneous samples composed of members of the general population and cancer patients. Furthermore, this was the first study to present head-to-head comparisons between the EQ-5D and the EQ-HWB-S seeking to inform discussions surrounding instrument selection. Indeed, the results obtained indicate a convergence between the measures, especially between overlapping dimensions, lending support to the validity of the EQ-HWB-S. The EQ-HWB-S performed similarly or better than the EQ-5D-5L among patient groups and is better able to differentiate among caregivers and respondents closer to full health. The second study assessed the feasibility and acceptability of the using SPP to value bolt-on items and compare it with the DCE. We produced evidence on how these two approaches compares in terms of general comprehension, cognitive burden and engagement and acceptability. Both DCE and SPP were well received and understood by respondents, the SPP methods emerges as comparatively simpler, less cognitively demanding and more engaging method, which also mitigates the well-documented phenomena of preference indifference between severity labels in the EQ-5D. These results informed the design of a large-scale valuation study that uses SPP and compares it to DCE as a means for valuing expanded descriptive systems for MAUIs of health and related measures. A secondary product of this study was the adaptation of a cognitive interviewing framework to be used to access choice methods. Finally, the third study presents the first large-scale application of the SPP method to value bolt-on dimensions (and head-to head comparison with the DCE) and demonstrates a set of methods well suited to future low-cost bolt-on valuation. According to our results, values for bolt-on health states can be accurately estimated based on standard EQ-5D value sets using data obtained through the application of ordinal preference elicitation methods like the DCE and the SPP. Furthermore, while the findings of this study indicate that further improvements can be made to the SPP method when applied to valuation studies, SPP NoPA models yielded promising results.