Andy Clegg is Professor of Geriatric Medicine at the University of Leeds, Honorary Consultant Geriatrician at Bradford Royal Infirmary, and Co-Director for Health Data Research UK North. Andy leads a large portfolio of ageing and frailty research including leadership of a research theme focused on improving care for older people with frailty in the NIHR Applied Research Collaboration, Yorkshire & Humber. Research expertise spans clinical trials of interventions, prognostic modelling using routine data, applied epidemiology and evidence synthesis. He is PI for the Personalised Care Planning for Older People with Frailty (PROSPER) NIHR-funded Research Programme, the NIHR HTA-funded Home-based Exercise for Older People (HERO) trial and the Community Ageing Research 75+ study – a longitudinal ageing and frailty cohort designed using trial within cohort methods. Andy previously led the development, validation and national implementation of the multi award-winning and NICE-recommended electronic frailty index (eFI) using data from around 1M UK patients contained in the ResearchOne and THIN primary care research databases, with major impact on UK health policy.