Estimation Of A Preference-Based Index From The EORTC QLQ-C30 (EORTC-8D)
The purpose of this study was to estimate a preference-based measure (the EORTC-8D) from a widely-used condition specific measure for cancer, the EORTC QLQ-C30. The EORTC QLQ-C30 is a widely used profile measure of health often used in clinical trials in Europe and Canada. However in its original form it cannot be used in economic evaluation as it does not incorporate preferences into its scoring system.
We derived a preference-based measure from the EORTC QLQ-C30. This measure enables EORTC QLQ-C30 data to be used to directly calculate QALYs for use in economic evaluation. Simply, for any dataset containing EORTC QLQ-C30 data, a utility score can be estimated for every observation in the dataset.
A preference-based measure consists of 1) a classification system and 2) preference weights that enable a utility score to be generated for every health state defined by the classification. We derived the EORTC-8D classification system using responses from patients newly diagnosed with multiple myeloma collected in a UK clinical trial. The classification system has 8 dimensions: physical functioning, role functioning, pain, emotional functioning, social functioning, fatigue and sleep disturbance, nausea, constipation and diarrhoea. Each dimension has 4 or 5 severity levels. The classification system generates a total of 81,920 health states.
We conducted a valuation survey using time trade-off for a random sample of the UK general population. We estimated the preference weights using regression analysis to enable utility values to be estimated for all states. The worst state has a utility value of 0.291 and the best state has a utility value of 1.
This study forms part of a wider cross-country study examining the use of preference-based measures from the EORTC QLQ-C30 across a variety of countries and different patient groups.
Rowen D, Brazier JE, Young TA, Gaugris S, Craig BM, King MT, Velikova, G. Deriving a preference-based measure for cancer using the EORTC QLQ-C30. Value in Health, [forthcoming].
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