Ross trained as a general practitioner in the UK and worked in Wairoa as a rural GP before going into health services management with the Waikato Area Health Board. He returned to the UK for a time as a senior lecturer and then Professor of Primary Health Care. His research centred on health outcomes research and pharmaco-epidemiology using large general practice databases. He has a particular interest in evidence-based medicine and has taught the principles of EBM at undergraduate and postgraduate levels.  

He is a Fellow of the Royal College of General Practitioners, UK, Fellow of the Faculty of Public Health, UK and Fellow of the Australasian Faculty of Public Health Medicine. He was a Member of the GPRD International Advisory Group, Medicines and Healthcare products Regulatory Agency (MHRA) UK, and a non-executive for the Surrey and Sussex Strategic Health Authority. Since returning to New Zealand in 2005 he has been Deputy Chair of the New Zealand Guidelines Group, Chair of the National Screening Advisory Group, a board member of Pinnacle Group Ltd, board member of the NZ Rural General Practice Network, a member of the Ministry of Heath’s Prostate Taskforce and a member of the Ministry of Health Cancer Registry Board. As well as his role as Professor of Population Health with the University of Waikato, Ross is also the Clinical Director of Strategy and Funding for the Waikato District Health Board.