Towards a novel framework for identifying commonalities and differences in older people's end-of-life trajectories: aims and interdisciplinary mixed-methods approach of the ERC-funded TRAJECT project.

Background: Older people who die from serious chronic disease typically experience long periods (months or years) of illness and complex fluctuations in their physical health and in their social, psychological and existential well-being. Our understanding of these end-of-life trajectories is very limited, focuses predominantly on physical function and clinical predictors and neglects inter-individual differences. A better understanding of end-of-life trajectories, including what is shared among people and what is individually specific, is needed for an optimal provision of palliative care and health services planning. Objectives: TRAJECT is a European Research Council-funded interdisciplinary project with a central aim to gain understanding of what is generalisable and what is individually specific in older people's end-of-life trajectories and in the circumstances that shape them. Design: Convergent mixed-methods design including a quantitative longitudinal survey study, a serial narrative study and a mortality follow-back survey. Methods and analysis: TRAJECT applies a novel methodological and analytical framework, examining trajectories through two distinct scientific lenses, both suited for uncovering variability as well as general principles: a structured quantitative approach to capture fluctuations in a standardised way, and an experience-focused qualitative approach to study the subjective stories and meanings behind changes in health. The findings of the quantitative and qualitative methods will be integrated through triangulation and by systematically threading key findings from one method across to the other. The research is conducted in Belgium. Discussion: This project will lead to a new understanding of the varied ways in which older people's end-of-life trajectories unfold and which circumstances and experiences shape them. It will also reveal which elements of trajectories are shared across groups of people and which are individually specific. These new insights will provide a much-needed evidence base concerning groups at risk of poor well-being as they near death, which is needed to optimise palliative care practice, needs assessment, as well as health service planning.