Karen has worked in public health since 1994 on research, policy, education, evaluation and advocacy. For twenty years this was with the International Union Against Tuberculosis and Lung Disease, an international non-governmental health organisation. From 2009 to 2016 she taught on operational research courses for health services, co-organising four courses in the Pacific.

She is a Senior Lecturer at the School of Population Health, University of Auckland and works as Research Coordinator for the Auckland Regional Public Health Service.

Karen has a Master of Arts in Languages and Literature and gained a Doctorate in Public Health from the London School of Hygiene and Tropical Medicine in 2005.