Title: Inequalities in later life frailty and wellbeing: an interdisciplinary approach to causality
Funder: Medical Research Council

Abstract: The challenges posed by the ageing of populations have been repeatedly documented, with recognition of the need to minimise dependency and to maximise social engagement and wellbeing. The proposed research is concerned with examining causal processes relating to frailty and wellbeing (both broadly defined) at older ages. It will use an interdisciplinary approach, bringing together key findings and innovative methods from across disciplines, will be comparative, using similarities and differences across national contexts to get a clearer understanding of policy influences, and will engage a full range of users in the conduct and dissemination of the research. Core data sources will be the English Longitudinal Study of Ageing (ELSA), sister studies in the US and mainland Europe, and a similar study in Canada. ELSA is a multidisciplinary study involving repeat surveys with a representative sample of people aged 50 and older, giving six sets of interview data (each two years apart), three sets of biological data (collected four years apart) and a detailed life-history interview. Data coverage includes: stored DNA and serum suitable for additional genetic, metabolic and biomarker analysis; already analysed biomarkers; direct assessments of cognitive and physical function; direct assessments of physical health; and a range of self-reports covering demographics, economics, health, participation in social, civic and cultural activities, and social networks. These data will be used to: develop measures of frailty and wellbeing; model life-course trajectories; examine the influences of genetics, socioeconomic position, social factors, and gene-environment interactions; explore the relationship of these factors with markers of metabolic processes; and identify factors relating to resilience and vulnerability to adverse events. Key hypotheses to be tested cover: the relationships between life-course trajectories, later life socioeconomic position and frailty and wellbeing; that socioeconomic effects will operate through the hypothalamic pituitary adrenal axis connected to processes relating to anabolic function and inflammation; that resilience and vulnerability can be identified and will result from environmental factors, genes, and gene-environment interactions; and that a detailed study of gene-metabolite-phenotypic interfaces will lead to the discovery of novel pathways to frailty and wellbeing. Traditional statistical approaches will be supplemented with innovative methods to handle missing data (selection models; pattern mixture models; shared parameter models; sensitivity analysis), longitudinal data (multilevel multistate competing risks models; growth mixture and structural equation modelling of trajectories; sequence analysis and optimal matching) and data from different national contexts (Integrative Data Analysis; latent variable approaches; and anchoring vignettes).


Research activity codes: 2.3 PSYCHOLOGICAL, SOCIAL AND ECONOMIC FACTORS;2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: GENERIC HEALTH RELEVANCE