William Whiteley is a Reader in the Centre for Clinical Brain Sciences, University of Edinburgh. He is also Senior Clinical Fellow in the Nuffield Department of Population Health, University of Oxford; and a consultant neurologist in NHS Lothian, working with patients with TIA, stroke and dementia. His work seeks to elucidate the mechanisms for prevention of disability due to stroke and dementia through the design, delivery and analysis of epidemiological studies and clinical trials. Of particular interest are: the contribution of vascular risk factors to dementia; the very long term follow-up of randomized trials; clinical diagnosis; and the better use of large electronic health record datasets for more efficient clinical trials and cohort studies.