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)