A framework for understanding quality of life in individuals without capacity

Purpose: The wide range of tools and methods developed for measuring and valuing health-related quality of life for use in economic evaluations are appropriate for use in most populations. However, for certain populations, specific tools may need to be developed to reflect the particular needs of that population. Patients without capacity - particularly patients with severe dementia - are such a population. At present, the tools available to economists for measuring and valuing quality of life in these patients lack validity. Here, we seek to understand the framework within which common instruments have been developed, critique these instruments with respect to patients with severely restricted capacity and to develop a new way of thinking about how to value health-related quality of life in such patients. Method: In this essay, we describe and critique the conceptual framework by which common instruments used for measuring and valuing quality of life have been developed. Results: We show that current common instruments used for measuring and valuing quality of life in general populations are not appropriate for populations with severely restricted capacity. Conclusions: We propose a new framework for thinking about quality of life in this population, based on notions of observable person-centred outcomes and utility derived from processes of care.