Through their Eyes: Defining 'Good Life' in Dementia for Health Economics and Outcomes Research

Despite progress in involving people living with dementia in health research, disparities remain, particularly in the field of health economics and outcomes research, where excessive reliance on proxy reports from care partners or healthcare professionals persists even when people are capable of self-reporting, leading to inequitable inclusion. This study aimed to understand the concept of a 'good life' from the perspectives of people living with dementia and examine how well current preference-based outcome measures used in health economics and outcomes research capture these perspectives. Twenty-three community-dwelling people with mild to moderate dementia in Ireland participated in in-depth interviews (September 2022-February 2023). Data were analysed using an adapted Colaizzi's seven-step phenomenological method, followed by mapping identified themes against ten commonly used preference-based outcome measures in dementia research. Results showed that participants perceived a ‘good life’ through independence, social connections, engagement with life, adaptation to changing abilities. For participants with moderate dementia, perceptions shifted from striving for independence and active life engagement to accepting assistance and increased social support. This transition reflects a journey of adaptation, where participants redefined their sense of a ‘good life’ with evolving challenges and capabilities. The mapping analysis revealed that current preference-based outcome measures vary considerably in their coverage of these themes (33-83%), with none fully capturing the dynamic and evolving nature of a 'good life' as described by participants. These findings expose disparities between lived experiences and current measurement frameworks in health economics and outcomes research in dementia, calling for developing flexible and adaptive approaches to quality of life assessment in progressive conditions—approaches that not only reflect quality of life as defined by those living with the condition but also accommodate its dynamic and evolving nature within individual journeys.