Maddy is a Researcher and Lecturer in Health Economics. She has worked at Health Economics Bristol (HEB) since 2019. Her main research activities involve conducting economic evaluations alongside trials delivered at Bristols Trial Centre (BTC). She has been involved in multiple primary and secondary health care trials, as well as public health trials, including: urology, domestic violence, chronic fatigue syndrome, sertraline medication for anxiety, physical activity, sedentary behaviour and diet. Her research interests are in standardising costing methods in economic evaluation and advancing the role of routine data in health economics research.

Maddy is an Associate Fellow of the Higher Education Academy and teaches on the MSc in Public Health and the short course 'Designing and Conducting Randomised Controlled Trials'. She has experience of teaching economic evaluation, evidence synthesis, critical appraisal, basic statistics and epidemiology, and qualitative research methods.