This is the second edition of the first comprehensive textbook about the measurement and valuation of health benefits for economic evaluation. The National Institute for Health and Care Excellence (NICE) and similar agencies around the word require cost-effectiveness evidence in the form of incremental cost per quality-adjusted life year (QALY) in order to make comparisons across competing demands on resources, and this has resulted in an explosion of theoretical and empirical work in the field. This book addresses the theoretical and practical considerations in the measurement and valuation of health benefit with empirical examples and applications to help clarify understanding and make relevant links to the real world. It includes a glossary of key terms and provides guidance on the use of different methods and instruments. This updated edition provides an-up-to date review of the theoretical basis of the QALY; the definition of health; the techniques of valuation (including ordinal); the modelling of health state values (including mapping between measures); a detailed review of generic preference-based measures and other instruments for obtaining health state utility values (with recent developments); cross-cultural issues (including the disability-adjusted life year); the aggregation of QALYs; and the practical issues surrounding the use of utility values in cost-effectiveness models. The book concludes with a discussion on the way forward in light of the substantial methodological differences, the role of normative judgements, and where further research is most likely to take forward this fascinating component of health economics.

HHe ea al lt th h E Ec co on no om mi ic cs s a an nd d D De ec ci is si io on n S Sc ci ie en nc ce e D Di is sc cu us ss si io on n P Pa ap pe er r S Se er ri ie es s No. 08/02A review of studies mapping (or cross walking) from non-preference based measures of health to generic preference-based measures INTRODUCTIONA common approach to assessing the outcomes of health care is to obtain patient reported descriptions of health status across various dimensions and then to apply a standardised numerical scoring system. There are many different measures of health, including several hundred condition specific measures of health designed for use in specific medical conditions or groups of condition (Spilker et al, 1990), and a number of generic measures designed to cover the core dimensions of health that are relevant across all medical conditions. Health measures can also be distinguished in terms of whether they generate a profile of dimension scores or a single index and if they produce a single index, whether or not the index has been derived using simple summation of item scores or by using preference weights obtained from patients or the general public (known as preference-based measures or multi-attribute utility scales).Patient reported measures of health have become widely used in clinical trials as primary or secondary outcomes. There is little agreement on which specific instruments should be used for this purpose. For assessing clinical efficacy, there is disagreement on whether to use a generic or condition specific measure, and between condition specific measures there is often disagreement amongst clinical researchers on the most appropriate instrument. As a result clinical trials around the world often use different measures for the same patient groups. This presents a substantial barrier to the synthesis of evidence.Preference-based measures of health are necessary to generate the health state utility values required to calculate QALYs for assessing the cost effectiveness of interventions.These are usually based on generic instruments (e.g. EQ-5D) that permit comparisons between patient groups, though there are examples of condition specific preference-based measures . Even for assessing clinical effectiveness, it could be argued that a preference-based index is necessary to deal with trade-offs made between outcomes. There has been a debate amongst health economists about the most appropriate preference-based generic measure to use in cost effectiveness analyses. Whilst the EQ-5D is the most widely applied in recent years (Brooks et al, 1996), the HUI3 (Feeny et al, 3 2002), QWB (Kaplan and Andersen, 1988), SF-6D (Brazier et al, 2002) and others continue to be used. However, different preference-based measures have been shown to generate different values on the same sample of patients (Marra et al, 2005; Feeny et al, 2004;Barton et al, 2004). Furthermore, many key clinical trials on the efficacy of new interventions do not have a generic measure and the recent FDA Guidance on using Patient Rep...

SummaryAs the number of preference-based instruments grows, it becomes increasingly important to compare different preference-based measures of health in order to inform an important debate on the choice of instrument. This paper presents a comparison of two of them, the EQ-5D and the SF-6D (recently developed from the SF-36) across seven patient/population groups (chronic obstructive airways disease, osteoarthritis, irritable bowel syndrome, lower back pain, leg ulcers, post menopausal women and elderly). The mean SF-6D index value was found to exceed the EQ-5D by 0.045 and the intraclass correlation coefficient between them was 0.51. Whilst this convergence lends some support for the validity of these measures, the modest difference at the aggregate level masks more significant differences in agreement across the patient groups and over severity of illness, with the SF-6D having a smaller range and lower variance in values. There is evidence for floor effects in the SF-6D and ceiling effects in the EQ-5D. These discrepancies arise from differences in their health state classifications and the methods used to value them. Further research is required to fully understand the respective roles of the descriptive systems and the valuation methods and to examine the implications for estimates of the impact of health care interventions.

Thirdly, using alternative models, the predictions are improved so that the local Japanese value set achieves MAE in the order of 0.01.

This project was funded by the UK Medical Research Council (MRC) as part of the MRC-NIHR methodology research programme (reference G0901486) and will be published in full in Health Technology Assessment; Vol. 18, No. 9. See the NIHR Journals Library website for further project information.

The EQ-5D questionnaire is a widely used generic instrument for describing and valuing health that was developed by the EuroQol Group. A primary objective of the EuroQol Group is the investigation of values for health states in the general population in different countries. As part of the EuroQol enterprise 11 population surveys were carried out in six Western European countries (Finland, Germany, The Netherlands, Spain, Sweden and the UK) to value health states as defined by the EQ-5D using a standardised visual analogue scale (EQ-5D VAS). This contribution reports how a European set of general population preference weights was derived from the data collected in the 11 valuation studies. The scores from this set of preference weights can be applied to generate a VAS-based weighted health status index for all the potential 243 EQ-5D health states for use in multi-national studies. To estimate the preference weights a multi-level regression analysis was performed on 82,910 valuations of 44 EQ-5D health states elicited from 6,870 respondents. Stable and plausible solutions were found for the model parameters. The R(2) value was 75%. The analysis showed that the major source of variance, apart from 'random error', was variance between individuals (28.3% of the total residual variance). These results suggest that VAS values for EQ-5D health states in six Western European countries can be described by a common model.

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SummaryIn cost-utility analysis, the numbers of quality-adjusted life years (QALYs) gained are aggregated according to the sum-ranking (or QALY maximisation) rule. This requires that the social value from health improvements is a simple product of gains in quality of life, length of life and the number of persons treated. The results from a systematic review of the literature suggest that QALY maximisation is descriptively flawed. Rather than being linear in quality and length of life, it would seem that social value diminishes in marginal increments of both. And rather than being neutral to the characteristics of people other than their propensity to generate QALYs, the social value of a health improvement seems to be higher if the person has worse lifetime health prospects and higher if that person has dependents. In addition, there is a desire to reduce inequalities in health. However, there are some uncertainties surrounding the results, particularly in relation to what might be affecting the responses, and there is the need for more studies of the general public that attempt to highlight the relative importance of various key factors. Copyright