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Geraint Lewis

2007–08 Harkness Fellow; Director of Population Health, Microsoft

Geraint Lewis, M.A., M.Sc., F.R.C.P., F.F.P.H., is a public health physician and is currently the director of Population Health at Microsoft. He qualified in medicine from Cambridge University, and worked as a junior doctor in London and Sydney before beginning higher specialist training in Public Health Medicine. Working at Croydon Primary Care Trust between 2004 and 2006, Lewis developed and implemented the virtual wards project. After leaving Croydon he became a visiting fellow at the King’s Fund and policy advisor at the UK Cabinet Office, before spending the 2007–08 academic year as a Commonwealth Fund Harkness Fellow at New York University. At NYU, his research explored how predictive modeling is being used in the United States. Lewis was the 2008 recipient of the National Directors’ Award at the Veterans Health Administration in Washington, D.C. His current interests include the development of predictive models for social care and predicting the impact of preventive interventions.

Harkness Project Title: Predictive Risk Modeling: Implications for Improving Access, Quality, and Cost-Effectiveness of “Upstream” Care

Mentors: John Billings, J.D., and David Olds, Ph.D.

Placement: Robert F. Wagner Graduate School of Public Service, New York University

Biography at time of Harkness Fellowship: Geraint Hywel Lewis, M.A., M.Sc., M.B., B.Chir., M.R.C.P., M.F.P.H., a 2007–08 Commonwealth Fund Harkness Fellow in Health Care Policy and Practice, is a public health physician working as an adviser at the Cabinet Office and as a visiting fellow at the King's Fund. Lewis developed and implemented the Virtual Wards project (aimed at avoiding emergency hospital admissions), which won an unprecedented four categories at the Health Service Journal awards and is being adopted across the United Kingdom and internationally. His current interest is in novel applications of predictive risk modeling, such as predicting admissions to nursing homes and forecasting social exclusion. He has published several articles in journals such as the BMJ, The Journal of Physiology, and the Health Service Journal, and has co-authored a postgraduate textbook on public health. Lewis holds a primary medical qualification from Cambridge and a master's degree in public health from the London School of Hygiene and Tropical Medicine, as well as membership of the Royal College of Physicians of London and of the Faculty of Public Health.

Project: Lewis evaluated the current use of predictive risk modeling in the United States for targeting upstream care. He undertook more than 30 semi-structured interviews with policy-makers, academics, vendors, consultants, providers and payers. As a second project, he developed a predictive tool to estimate the capacity of individual pregnant mothers to benefit from the Nurse Family Partnership — a program of prenatal and infancy home visiting for socially disadvantaged mothers bearing first children. To develop the tool, he used longitudinal data from three randomized controlled trials of the program.

Career Activity Since Fellowship

  • Director of Population Health, Microsoft, 2022–
  • Honorary Clinical Senior Lecturer, University College London, 2016–
  • Chief Data Officer, NHS England, 2013–2022
  • Director of Open Information, NHS Clinical Commissioning Board, 2012
  • Senior Director, Clinical Outcomes & Analytics, Walgreens, 2012
  • Senior Fellow, The Nuffield Trust, 2009

Current Positions (updated 4/2023)

  • Director of Population Health, Microsoft
  • Honorary Clinical Senior Lecturer, University College London

Harkness-Related Publications

Lewis G, Kirkham H, Duncan I, Vaithianathan R. How health systems could avert 'triple fail' events that are harmful, are costly, and result in poor patient satisfaction. Health Affairs 2013 Apr;32(4):669-76.

Lewis G, Wright L, Vaithianathan R. “Multidisciplinary case management for patients at high risk of hospitalization: comparison of virtual ward models in the United kingdom, United States, and Canada.” Popul Health Manag. 2012 Oct;15(5):315-21.

Bardsley M, Georghiou T, Chassin L, Lewis G, Steventon A, Dixon J. “Overlap of hospital use and social care in older people in England.” J Health Serv Res Policy. 2012 Jul;17(3):133.

Steventon A, Bardsley M, Billings J, Georghiou T, Lewis GH. “The role of matched controls in building an evidence base for hospital-avoidance schemes: a retrospective evaluation.” Health Serv Res. 2012 Aug;47(4):1679-98.

Lewis GH, Vaithianathan R, Hockey PM, Hirst G, Bagian JP. “Counter-heroism, Common Knowledge, and Ergonomics: Concepts from Aviation that Could Improve Patient Safety.” Milbank Quarterly 2011; 89(1):4-38.

Lewis GH. “Predictive Modeling in Action: How ‘Virtual Wards’ Help High-Risk Patients Receive Hospital Care at Home.” The Commonwealth Fund, August 2010. 

Lewis GH. “Impactability Models: Identifying the Subgroup of High Risk Patients Most Amenable to Hospital Avoidance Programs.” Milbank Quarterly; 88(2).

Vaithianathan R, Lewis G. “The NHS as an insurer.” Journal of Health Services Research and Policy, 2010 Jul; 15(3):171-3. Epub 2010 Mar 4.

Vaithianathan R, Lewis, G. “Operational Independence for the NHS”, BMJ 2008;337:1497.