Measuring and valuing mental health for use in economic evaluation.

This article presents research undertaken as part of a wider programme of work concerned with measuring and health and wellbeing for economic evaluation. The focus is on developing quality adjusted life years (QALYs) in mental health, but the issues are common across all areas of health care. The article begins by reviewing the issues of what should be valued (health or broader notions of wellbeing), how mental health and wellbeing should be described, how mental health states should be valued and who should do the valuing. The article presents four pieces of work. The first is a re-analysis of the ONS Psychiatric Morbidity 2000 Survey to provide evidence on the relevance of generic measures across different mental health disorders. It found that common mental health problems, such as anxiety and depression, had a significant impact on the generic preference-based measure of health in the SF-6D, but psychosis and personality disorders did not. The article then presents two studies using the ratings of people experiencing the states of health. Both studies found that people experiencing different health states gave mental health greater weight than physical health compared to members of the general public trying to imagine the health states. Finally, the article presents a study developing a condition-specific preference-based measure for calculating QALYs from an existing measure of mental health, the CORE-OM, using modern psychometric methods to construct health states amenable to valuation. It also considers a proposal to develop an entirely new QALY measure in mental health.