An introduction to the measurement and valuation of health for NICE submissions
The EQ-5D comes with a pre-existing value set obtained from a representative sample of the UK general population using the time trade-off technique. Other generic preference-based measures are available, such as HUI3 and SF-6D and these can be used in sensitivity analyses. For children NICE has been...
| Main Authors: | , |
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| Format: | eBook |
| Language: | English |
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London
National Institute for Health and Clinical Excellence (NICE)
August 2011, 2011
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| Series: | NICE DSU technical support document
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| Subjects: | |
| Online Access: | |
| Collection: | National Center for Biotechnology Information - Collection details see MPG.ReNa |
| Summary: | The EQ-5D comes with a pre-existing value set obtained from a representative sample of the UK general population using the time trade-off technique. Other generic preference-based measures are available, such as HUI3 and SF-6D and these can be used in sensitivity analyses. For children NICE has been less prescriptive, but would like to see standardized and validated preference-based measures to be more widely used. The EQ-5D can be collected in trials, though for many states it may be more appropriate to collect the data in observational or routine data sets, or to use existing estimates from the literature. Where relevant EQ-5D data are not available, then another solution would be to map from another measure of HRQL or disease severity that has been used in relevant studies and to predict EQ-5D responses from statistical mapping functions. These can be estimated from other data sets containing both instruments. NICE requires consistency in its decision making and so has developed a reference case of methods for Technology Appraisal that includes the measurement and valuation of health. This TSD starts with an overview of the reference case, and then goes on to examine what evidence is required to justify using an alternative to NICE's preferred measure, the EQ-5D. The key components of the NICE reference case are as follows. The QALY is the recommended measure of the benefits of an intervention. It combines the outcomes of survival and health related quality of life, by placing the latter on a scale where zero represents being dead and one is full health. There are a variety of approaches and techniques for valuing states of health-related quality of life (HRQL). The NICE reference case prefers the generic EQ-5D in adults as reported by the patient or their close carer when they are unable to do so. These criteria would preferably be assessed across the five dimensions of the measure as well as the overall index, though this is rarely done. Careful consideration must be given to the relevance of the variables used to test validity. There will always remain a degree of judgment to be exercised by NICE in any patient group. The rest of this TSD series considers in more detail the key issues around the use of values in the literature (TSD 9), mapping (TSD 10) and the alternative methods available where EQ-5D is shown to be inappropriate (TSD 11). Finally, the last in the series considers the use of HSUVs in economic models (TSD 12). The other TSDs in this series offer lists of recommended research in their specific areas and these are not repeated here. This strategy is accepted by NICE in the absence of EQ-5D data, but it is always second best to the direct use of EQ-5D and may come with a penalty of increased uncertainty. In some situations, NICE recognises that the EQ-5D may not be appropriate. However, it is difficult to prove a measure of HRQL is or is not valid in a particular patient group in the absence of a gold standard measure. NICE requires empirical evidence to demonstrate the EQ-5D is inappropriate in terms of the properties of content validity, construct validity, and responsiveness. Content validity is concerned with whether the instrument covers all the dimensions of HRQL of importance to patients. Construct validity requires quantitative evidence on whether the measure reflects known differences between groups or converges with other relevant measures. Responsiveness is the extent to which the EQ-5D reflects changes in HRQL overtime. In terms of what is discussed in this TSD, the main research gaps are in determining the appropriateness of EQ-5D in different patient groups and further work is required to establish the most appropriate preference-based measure in children |
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| Physical Description: | 1 PDF file (29 pages) |