Dr. Tierney is a general internist, Associate Professor of Medicine at the Indiana University School of Medicine, and a research scientist at the Regenstrief Institute. He received an undergraduate degree in biological sciences at Indiana University where he also received his MD degree in 1976. He served as intern and resident at the Indiana University Medical Center in Indianapolis and was Chief Resident in Medicine at Wishard Memorial Hospital, Indiana’s only tax-supported public teaching hospital. In 1980, he joined Dr. Clem McDonald in the Regenstrief Institute’s Computer Science Research Section, for which he currently serves as Associate Director. His research focuses on the implementation and assessment of health information systems in Wishard Hospital. Specifically, he helped implement one of the first outpatient computer-based physician order-entry programs and showed that one could lower the costs of outpatient diagnostic testing by providing prior test results, probabilities of abnormal results, and costs of tests. He is currently assisting Dr. McDonald in developing and implementing this CPOE system on the inpatient medicine service of Wishard Hospital and designing and conducting a randomized, controlled trial of its effects on inpatient ordering, length of stay, costs of care, and errors. He has also performed clinical epidemiologic studies of clinical data stored in the Regenstrief Medical Record System, mainly to identify risk factors for abnormal test results. He also uses these data to identify patients in primary care who are eligible for studies. In addition to his research, Dr. Tierney also practices general internal medicine in inpatient, emergency room, and outpatient primary care venues. He was also the Director of Medical Manpower for the 1987 Pan American Games in Indianapolis, for which he also served as Sports Medicine Officer for Track and Field. He was been elected to Fellowship in the American College of Physicians in 1987.