Dr. Eunice Chang is a mathematician and statistician with more than 20 years’ experience in the application of statistical analysis and design in a range of data types, including longitudinal surveys; commercial, Medicare, and Medicaid claims; electronic health records; and many others. At PHAR, she leads many secondary data analyses, and provides methodological and statistical support on a variety of other project types. Before joining PHAR, she was Chief Statistician and Manager of Health Informatics and Health Outcomes Research at Prescription Solutions in Costa Mesa, California, where she was responsible for the methodology of retrospective and prospective clinical outcomes research and the evaluation of quality initiatives and disease-state management programs. This required the development of predictive models for pharmacy and medical costs and other healthcare utilization with data-mining techniques, such as regression models, decision trees, and neural networks. Dr. Chang also served as Senior Statistician at PacifiCare Health Systems, where she led a team focused on quality initiatives and health improvement projects, including the development of a systematic sampling program for HEDIS 1999 measures. Earlier in her career, she provided statistical support for research grant proposals and study design at the David Geffen School of Medicine at UCLA.