Noralou Roos is a trailblazer in using big data systems analysis to understand social determinants of health promoting effective universal health care policies. The Manitoba Centre for Health Policy, founded by Dr. Roos and her husband Leslie Roos, tracks the health and health systems use of a million Manitobans for more than 50 years, leading to the development of a data repository making it possible to relate a population’s health care system use to its health care needs. Dr. Roos’ model for assemblage and analysis of administrative health care data serves as a global model supporting after-market safety and effectiveness tracking of new pharmaceuticals, actionable policies for optimal allocation of health care resources, notably children’s health care, and the diagnosis and treatment of poverty. Honoured and imitated by institutions and governments worldwide, Dr. Roos’ work, decades ahead of its time, helped to establish comprehensive large-scale data analysis as the pathway to effective population health care management, providing fundamentally new opportunities for understanding key health and health care research and policy issues. Dr. Roos’ EvidenceNetwork.ca broadly disseminated authoritative population health care information to the public, using media to promote informed public understanding of health care issues.