Geraint is the Chief Data Officer of NHS England. He trained in medicine at the University of Cambridge, and holds a Masters in Public Health from the London School of Hygiene and Tropical Medicine. He worked in acute medicine and emergency medicine in the UK and Australia before specialising in public health. He is the author of Mastering Public Health (a leading postgraduate text book on population health), as well as many peer-reviewed papers in journals such as Health Affairs, Milbank Quarterly, and the British Medical Journal. Geraint was previously Senior Director for Clinical Outcomes and Analytics at Walgreens in Chicago, and was a Senior Fellow of the Nuffield Trust, a leading health policy think-tank based in London.