My scientific contributions relate innovative use of evidence to inform clinical and public policy decision making. My early work centered on stroke prevention and treatment (questionable value of carotid testing in low risk individuals, underuse and poor quality of use of anticoagulation for stroke prevention, the value of aggressive anticoagulation monitoring including the use of patient self-testing strategies, and the unappreciated role of rehabilitation in stroke care.) In cognitive impairment, my contribution has been to clarify the role of diagnostic testing for Alzheimer’s disease, the importance of early diagnosis on planning and avoidance of unnecessary testing and evaluation. In chronic kidney disease, I have guided a series of projects aimed at developing evidence-based tailored strategies for improving conformance to guidelines. More recently, my work has applied simulation modeling to clarify the challenges of a rapidly aging population, including future prevalence of disability and the impact of education the trajectory of prevalence, understanding the role of different forms of long-term care services in alleviating caregiver burden, and estimating health care manpower requirements under alternative models of care. This work has led to the formulation of a needs-based framework for healthcare delivery and the development, validation and application of the Simple Segmentation Tool (SST), a simplified inventory of patient-level health service needs, different combinations of which can be mapped to different appropriate means for addressing these needs. I have extended this effort from developed countries (US, Singapore, and Switzerland) to low/middle income countries (Cambodia, Thailand).