Joseph is a medical doctor who specializes in public health epidemiology. He is Deputy Director for Epidemiology and Public Health at the Health Services & Outcomes Research department of the National Healthcare Group. He is actively involved in evaluations of health services and health programs, training activities, health technology assessments and health outcomes studies. He is concurrently Senior Lecturer at the Lee Kong Chian School of Medicine, Nanyang Technological University. Prior to joining NHG, he was an Assistant Professor of Preventive Medicine in the Philippines and was involved in clinical quality monitoring.