Ruth is a public health physician and epidemiologist working in the areas of mental health research, social epidemiology, cancer epidemiology and health services research. The main focus of her current work is mental health epidemiology and the physical health of people with experience of mental health conditions. She leads the Electronic data for Mental health research (EleMent) group: Te Raraunga Hinengaro.

Ruth is principal investigator the Tupuānuku research project funded by the Health Research Council to investigate the factors contributing to inequities in physical health outcomes for people with experience of mental illness or addiction in Aotearoa. Ruth is also working on a number of projects using routine data on mental health service use in New Zealand (PRIMHD) linked to other datasets, including projects examining mental health service use in later life, mental health care in emergency departments, and mental health service provision for Māori including work with Dr Paula King on the health and wellbeing impacts of incarceration for Māori.