Julia qualified with distinction from Sheffield University Medical School in 1989 where she was awarded the Prize in Medicine, Surgery, General Practice and Obstetrics and Gynaecology. In 1995 she was awarded a distinction in the MRCGP examination and awarded FRCGP in 2005. She became a Member of the Royal College of Physicians in 1994, and a Fellow in 2013. She was appointed as Lecturer at the University of Nottingham in 1995, Senior Lecturer in 1999, Reader in 2004. She was promoted to Professor of Clinical Epidemiology & General Practice in 2005 where she stayed until her appointment at the University of Oxford.
In 2009 she was awarded the John Fry Award by the Royal College of General Practitioners. She was awarded RCGP paper of the year for the best paper published in the cancer category (2012) and cardiovascular category (2018). In 2013 she was awarded the Dr John Perry Prize for an outstanding contribution to NHS IT for her work developing the widely used www.openpseudonymiser.org too. She is the co-founder of the QResearch database (www.qresearch.org) which is one of the largest clinical research databases worldwide. In 2020, it has doubled in size to to cover over 2500 GP practices, representing approximately 40% of the UK population. In DeLIVER, Julia is leading a program of work (with Weiqi Liao) to evaluate the epidemiology of HCC in the UK and to develop risk prediction scores for HCC detect.