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This article develops and compares methods for mapping to preference-based measures using mixture model approaches. We use data from 856 patients with asthma collected as part of the Multi-Instrument Comparison (MIC) international project to map from the Asthma Quality of Life Questionnaire (AQLQ) to both EQ5D-5L and HUI-3. We estimate adjusted limited dependent variable mixture models (ALDVMMs) and beta-regression based mixture models and explore the optional inclusion of the gap between full health and the next value, and a mass point at the next feasible value.
Both model types are able to closely fit the data without biased characteristic of many mapping approaches. Skilled judgement is critical in determining the optimal model. Caution is required in ensuring a truly global maximum likelihood has been identified.
L A Gray, M Hernández Alava, A J Wailoo
EQ-5D is used in cost-effectiveness studies underlying many important health policy decisions. The original 3-level version of EQ-5D is being replaced with a more sensitive 5-level version. We model the relationship between EQ-5D-3L and EQ-5D-5L using two different reference datasets and examine how differences impact on cost-effectiveness in nine case studies.
M Hernandez Alava, A Wailoo, S Grimm, S Pudney, M Gomes, Z Sadique, D Meads, J O’Dwyer , G Barton, L Irvine.
Using data from the Millennium Cohort Study, we investigate the dynamic relationship between underlying family lifestyle and childhood obesity during early childhood. We use a dynamic latent factor model, an approach that allows us to identify family lifestyle, its evolution over time and its influence on childhood obesity and other observable outcomes. We find that family lifestyle is persistent and has a significant influence on childhood weight status as well as other outcomes for all family members. Interventions should therefore be prolonged and persuasive and target the underlying lifestyle of a family as early as possible during childhood in order to have the greatest cumulative influence.
L A Gray, M Hernandez Alava, M P Kelly, M J Campbell
There is limited evidence on the association of health status and comorbidities of marital/cohabitated partners despite the consequences for public policy on disability. Any tendency for disease or disability to be concentrated within couples will affect the social cost of disease. A second reason for interest in comorbidity within couples is that it may give useful insights regarding the causal processes generating health outcomes later in life.
A Davillas, S Pudney
Health state utilities are key parameters in cost utility analysis. In the absence of health related quality of life (HRQoL) data collected directly from clinical trials, published literature are relied upon for health utilities estimates.
The review found few studies that reported preference-based health utilities in children with asthma. There is also a lack of robust estimates on utility decrement associated with asthma exacerbation in children.
Future studies in children with asthma are encouraged to incorporate HRQoL data collection into the study design.
This review also serves as an example on how health utilities are searched, identified and critically appraised for appropriateness to be used in an economic model.
W Sun Kua, S Davis
Screening for multiple cancer types in a single test has the potential to offer both cost savings and health gains in comparison to offering several separate type-specific programmes. This study developed an early economic model to evaluate an early generic cancer screening programme and to identify what evidence needs to be generated to allow for robust economic evaluation in the future. There was a substantial degree of uncertainty in the health economic effects of a generic cancer screening programme. Future research is needed into: the lifetime treatment costs for each cancer type by stage at diagnosis; the natural history of multiple cancer types; the follow up pathways for false positive screens; and the QALY gains from earlier detection of cancer.
S Whyte, D Pollard, I Cree
Preference elicitation tasks for health state valuation are generally conducted in one-off interviews that may not give participants enough time to reflect and deliberate on the complex process of valuing health. The aim of this study is to understand if providing members of the public with an opportunity to engage in reflection and deliberation will change their health state preferences. There were large number of changes to health state values at the individual level, but these did not lead to statistically significant changes at the aggregate level. The use of conventional methods with one-off interviews, for purposes that use aggregated valuations, was not invalidated by this study.
M. Karimi, J. Brazier, S. Paisley
This study investigates the thought processes of participants valuing health states using semi-structured interviews and a think-aloud protocol. A range of non-health factors were considered when valuing health, and ultimately participants valued health by judging the non-health consequences of the health states. The importance of non-health factors in valuing health has implications for methods of describing health, for example whether the focus should be health or broader well-being, and for methods of testing and developing informed preferences.
M. Karimi, J. Brazier, S. Paisley
The 2003 Health Economics paper by Dolan, Olsen, Menzel and Richardson on “An inquiry into the different perspectives that can be used when eliciting preferences in health” presents a conceptual framework of six perspectives along two dimensions: preferences (personal, social, and socially inclusive personal) and context (ex ante and ex post). The objective of our paper is to re-think this framework, building on examples using monetary and non-monetary valuations (i.e health state valuation). We propose an extended framework with 20 possible perspectives, and discuss 11 of these.
A Tsuchiya, V Watson
Factors influencing the use of research for policy-making: An umbrella review protocol
In this paper, we present the protocol for an umbrella review (overview of reviews) about factors affecting the use of research by policy-makers. We will focus on barriers and facilitators affecting the use of research outputs and on preferred ways of presenting the results of research to policy-makers. The results of this review will guide the design of a qualitative study with policy-makers.
E E. Atienzo, E Kaltenthaler, S K. Baxter
Copula-based modelling of self-reported health states An application to the use of EQ-5D-3L and EQ-5D-5L in evaluating drug therapies for rheumatic disease
EQ-5D is used in cost-effectiveness studies underlying many important health policy decisions. The original 3-level version of EQ-5D is being replaced with a more sensitive 5-level version but there little is known about the consequences of this change. In this paper, we develop new statistical methods to investigate how well the old and new versions of EQ-5D work, and we find systematic differences in the way they measure mobility problems and pain. We use the findings to re-examine a cost-effectiveness evaluation of alternative drug therapies for rheumatoid arthritis.
M Hernandez-Alava, S Pudney
This paper presents a protocol to summarise the process used to conduct a qualitative evidence synthesis of patient experiences for five key vascular conditions; peripheral arterial disease, carotid artery disease, abdominal aortic aneurysm, varicose veins and venous leg ulcers. The synthesis will form part of a wider project identifying patient outcomes for the included vascular conditions.
R Duncan, A Booth, H B Woods, M Essat, P Phillips, E Poku, E Kaltenthaler, G Jones, J Michaels
Patient reported outcome measures (PROMs) are increasing being used in clinical practice to assess the quality of life of patients. However, PROMs used to assess quality of life of patients with abdominal aortic aneurysm (AAA) in clinical setting are equivocal in terms of their reliability, validity and suitability. The aim of this protocol is to outline the systematic process we intend to use to identify, summarise and assess PROMs that have been administered in patients with AAA.
M Essat, E Poku, R Duncan, P Phillips, H Woods, S Palfreyman, G Jones, E Kaltenthaler and J Michaels
This paper provides details of how the EQ-5D-5L value set was derived, focusing on the methods used to model the stated preference data. Results for different model specifications, and taking different interpretations of the data, are presented and discussed. This paper is intended to accompany HEDS Discussion Paper ‘Valuing health-related quality of life: an EQ-5D-5L value set for England’.
Y Feng, N Devlin, K Shah, B Mulhern, B van Hout
This paper reports the methods and findings from the EQ-5D-5L value set for England study. The value set is derived from the stated preference data of 996 members of the English general public. The study design followed the EuroQol Group’s international protocol for valuing EQ-5D-5L health states. A single value set is reported, and implications for public decisions made using EQ-5D-5L data are discussed. This paper is intended to accompany HEDS Discussion Paper ‘New methods for modelling EQ-5D-5L value sets: an application to English data’.
N Devlin, K Shah, Y Feng, B Mulhern, B van Hout