His research interests are focused on improving the health and wellbeing of people with chronic and long-term health conditions. Much of his work has centred on improving the self-management of diabetes in general practice. This has included researching where blood glucose monitoring is helpful, supporting people in making best use of their medicines, and developing and testing digital health systems. His research group uses a wide range of research methods including qualitative research, analysing electronic health records, and clinical trials to produce evidence. He is co-lead for the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre Digital Health and Technology theme. He has an h-index of 56 and an i-10 index of 153. He was appointed NIHR Senior Investigator in 2013 and was reappointed in 2018 for a further term.