Estimating an exchange rate between the EQ-5D-3L and ASCOT

Background The aim was to estimate an exchange ratebetween EQ-5D-3L and the Adult Social Care OutcomeTool (ASCOT) using preference-based mapping via com-mon time trade-off (TTO) valuations. EQ-5D and ASCOTare useful for examining cost-effectiveness within thehealth and social care sectors, respective ly, but there is apolicy need to understand overall benefits and compareacross sectors to assess relative value for money. Standardstatistical mapping is unsuitable since it relies on concep-tual overlap of the measures but EQ-5D and ASCOT havedifferent conceptualisations of quality of life.Methods We use a preference-based mapping approach toestimate the exchange rate using common TTO valuationsfor both measures. A sample of health states from eachmeasure was valued using TTO by 200 members of the UKadult general population. Regression analyses are used togenerate separate equations between EQ-5D-3L andASCOT values using their original value set and TTOvalues elicited here . These are solved as simultaneousequations to estimat e the relationship between EQ-5D- 3Land ASCOT.Results The relationship for moving from ASCOT to EQ-5D-3L is a linear transformation with an intercept of-0.0488 and gradient of 0.978. This enables QALY gainsgenerated by ASCOT and EQ-5D to be compared acrossdifferent interventions.Conclusions This paper estimated an exchange ratebetween ASCOT and EQ-5D-3L usin g a preference-basedmapping approach that does not compromise the descrip-tive systems of the two measures. This contributes to thedevelopment of preference-based mapping through the useof TTO as the common metric used to estimate theexchange rate between measures

Experience-based utility and own health state valuation: why do it and how to do it

In the estimation of population value sets for measures such as the EQ-5D, there is increasing interest in asking respondents to value their own health state, sometimes referred to as “experience-based utility values”, rather than hypothetical health states. Evidence shows that these experience-based utility values differ to hypothetical health state values. This may be attributed to many reasons. This paper first critically examines: why this difference is important, whether own visual analogue scale (VAS) or time trade-off (TTO) really measure experience-based utility values, the biases from current methods of collecting experience-based utility data, and the modelling of the data. Second, the paper reviews some of the normative arguments for and against using own health state valuation. Finally, the paper also examines other ways own health state values can be taken into account, such as including the use of informed general population preferences that may better take into account experience-based values

Experience-based utility and own health state valuation: why do it and how to do it

In the estimation of population value sets for measures such as the EQ-5D, there is increasing interest in asking respondents to value their own health state, sometimes referred to as “experience-based utility values”, rather than hypothetical health states. Evidence shows that these experience-based utility values differ to hypothetical health state values. This may be attributed to many reasons. This paper first critically examines: why this difference is important, whether own visual analogue scale (VAS) or time trade-off (TTO) really measure experience-based utility values, the biases from current methods of collecting experience-based utility data, and the modelling of the data. Second, the paper reviews some of the normative arguments for and against using own health state valuation. Finally, the paper also examines other ways own health state values can be taken into account, such as including the use of informed general population preferences that may better take into account experience-based values

Improving the measurement of QALYs in dementia: Developing patient- and carer-reported health state classification systems using Rasch analysis

Objectives: Cost-utility analysis is increasingly used to inform resource allocation. This requires a means of valuing health states before and after intervention. Although generic measures are typically used to generate values, these do not perform well with people with dementia. We report the development of a health state classification system amenable to valuation for use in studies of dementia, derived from the DEMQOL system, a measure of health-related quality of life in dementia by patient self-report (DEMQOL) and carer proxy-report (DEMQOL-Proxy). Methods: Factor analysis was used to determine the dimensional structure of DEMQOL and DEMQOL-Proxy. Rasch analysis was subsequently used to investigate item performance across factors in terms of item-level ordering, functioning across subgroups, model fit and severity-range coverage. This enabled the selection of one item from each factor for the classification system. A sample of people with a diagnosis of mild/moderate dementia (n=644) and a sample of carers of those with mild/moderate dementia (n=683) were used. Results: Factor analysis found different 5-factor solutions for DEMQOL and DEMQOL-Proxy. Following item reduction and selection using Rasch analysis, a 5-dimension classification for DEMQOL and a 4-dimension classification for DEMQOL-Proxy were developed. Each item contained 4 health state levels. Conclusion: Combining Rasch and classical psychometric analysis is a valid method of selecting items for dementia health state classifications from both the patient and carer perspectives. The next stage is to obtain preference weights so that the measure can be used in the economic evaluation of treatment, care and support arrangements for dementia

Future directions in valuing benefits for estimating QALYs: Is time up for the EQ-5D?

The widespread adoption of the EuroQol 5-dimensional questionnaire (EQ-5D) has been important for the comparability, transparency, and consistency of economic evaluations for informing resource allocation in healthcare. The objectives of this article were to (1) critically assess whether the widespread adoption of the EQ-5D and its time trade-off–based value sets to inform economic evaluation is likely to continue and (2) speculate about how benefits may be measured and valued to inform economic evaluation in the future. Evidence supports the use of the EQ-5D in many areas of health, but there are notable gaps. Furthermore, there has been interest among some policy makers in measuring changes in well-being, and in using common outcomes across sectors. Possibilities for measuring well-being alongside health can be achieved through bolt-on dimensions or an entirely new measure capturing both health and well-being. Nevertheless, there are significant concerns about the logic of estimating a common utility function. The development of online valuation methods has had a major impact on the field, which is likely to continue. We, however, recommend more allowance for respondents to consider their answers. There is an ongoing debate on the role of patient values or experience-based values. To date, this has seen limited take-up by decision makers and there are significant technical problems to obtaining representative and meaningful values. Policy makers and the general population must decide on the focus and scope of benefits that are incorporated into economic evaluation, and current evidence on this is mixed. In part, this will determine whether the widespread adoption will continue

A Review of Generic Preference-Based Measures for Use in Cost-Effectiveness Models

Generic preference-based measures (GPBMs) of health are used to obtain the quality adjustment weight required to calculate the quality adjusted life year (QALY) in health economic models. GPBMs have been developed to use across different interventions and medical conditions and typically consist of a self-complete patient questionnaire, a health state classification system, and preference weights for all states defined by the classification system. Of the six main GPBMs, the three most frequently used are: the HUI3, the EQ-5D (3 and 5 level), and the SF-6D. There are considerable differences in GPBMs in terms of the content and size of descriptive system (i.e. the numbers of dimensions of health and levels of severity within these), the methods of valuation (e.g. time-trade off (TT0), standard gamble (SG)) and the populations (e.g. general population, patients) used to value the health states within the descriptive system. Although GPBM are anchored at one (full health) and zero (dead) they produce different health state utility values (HSUV) when completed by the same patient. Considerations when selecting a measure for use in a clinical trial include practicality, reliability, validity and responsiveness. Requirements of reimbursement agencies may impose additional restriction on suitable measures for use in economic evaluations such as the valuation technique (TTO, SG) or the source of values (general public versus patients)

A Review of Generic Preference-Based Measures for Use in Cost-Effectiveness Models

Generic preference-based measures (GPBMs) of health are used to obtain the quality adjustment weight required to calculate the quality adjusted life year (QALY) in health economic models. GPBMs have been developed to use across different interventions and medical conditions and typically consist of a self-complete patient questionnaire, a health state classification system, and preference weights for all states defined by the classification system. Of the six main GPBMs, the three most frequently used are: the HUI3, the EQ-5D (3 and 5 level), and the SF-6D. There are considerable differences in GPBMs in terms of the content and size of descriptive system (i.e. the numbers of dimensions of health and levels of severity within these), the methods of valuation (e.g. time-trade off (TT0), standard gamble (SG)) and the populations (e.g. general population, patients) used to value the health states within the descriptive system. Although GPBM are anchored at one (full health) and zero (dead) they produce different health state utility values (HSUV) when completed by the same patient. Considerations when selecting a measure for use in a clinical trial include practicality, reliability, validity and responsiveness. Requirements of reimbursement agencies may impose additional restriction on suitable measures for use in economic evaluations such as the valuation technique (TTO, SG) or the source of values (general public versus patients)

Using a discrete choice experiment involving cost to value a classification system measuring the quality of life impact of self-management for diabetes

Objective: This paper describes the use of a novel approach in health valuation of a discrete choice experiment (DCE) including a cost attribute to value a recently developed classification system for measuring the quality of life impact (both health and treatment experience) of self-management for diabetes. Methods: A large online survey was conducted using DCE with cost on UK respondents from the general population (n=1,497) and individuals with diabetes (n=405). The data was modelled using a conditional logit model with robust standard errors. The marginal rate of substitution (MRS) was used to generate willingness to pay estimates for every state defined by the classification system. Robustness of results was assessed by including interaction effects for household income. Results: There were some logical inconsistencies and insignificant coefficients for the milder levels of some attributes. There were some differences in the rank ordering of different attributes for the general population and diabetes patients. The willingness to pay to avoid the most severe state was £1,118.53 per month for the general population and £2,356.02 per month for the diabetes patient population. The results were largely robust. Conclusion: Health and self-management can be valued in a single classification system using DCE with cost. The MRS for key attributes can be used to inform cost-benefit analysis of self-management interventions in diabetes using results from clinical studies where this new classification system has been applied. The method shows promise, but found large willingness to pay estimates exceeding the cost levels used in the survey

Developing a dementia-specific preference-­based quality of life measure (AD-5D) in Australia: a valuation study protocol

Introduction: Generic instruments for assessing health-related quality of life may lack the sensitivity to detect changes in health specific to certain conditions, such as dementia. The QOL-AD is a widely used and well validated condition-specific instrument for assessing health-related quality of life for people living with dementia, but it does not enable the calculation of Quality Adjusted Life Years (QALYs), the basis of cost utility analysis. This study will generate a preference-based scoring algorithm for a health state classification system (the AD-5D) derived from the QOL-AD. Methods and analysis: Discrete choice experiments with duration (DCETTO) and best-worst scaling (BWS) health state valuation tasks will be administered to a representative sample of 2,000 members of the Australian general population via an online survey and to 250 dementia dyads (250 people with dementia and their carers) via face-to-face interview. A multinomial (conditional) logistic framework will be used to analyse responses and produce the utility algorithm for the AD-5D. Ethics and dissemination: The algorithms developed will enable prospective and retrospective economic evaluation of any treatment or intervention targeting people with dementia where the QOL-AD has been administered and will be available online. Results will be disseminated through journals that publish health economics articles and through professional conferences. The study has ethical approval

New clinical presentations of invasive aspergillosis in non-conventional hosts

Infections by Aspergillus spp. are most typically associated with invasive pulmonary aspergillosis. However, an increasing number of reports deal with unusual manifestations of invasive aspergillosis. In the lung this may take the form of chronic invasive pulmonary aspergillosis, bronchocentric granulomatosis or tracehobronchitis. A number of extrapulmonary infections have been noted, sometimes in immunocompetent individuals. Examples include vertebral osteomyelitis, primary cutaneous aspergillosis (such as in premature neonates), prosthetic vascular graft infection and infective endocarditis. Early recognition of these entities, prompt initiation of new, highly active antifungal therapies and adjunctive surgical management may improve the prognosis of these conditions