David Lawrence Sackett was a clinical epidemiologist and pioneer of evidence-based medicine. He obtained his medical degree from the University of Illinois College of Medicine and a Master of Science in Epidemiology from Harvard University. Sackett joined the newly established medical school at McMaster University in the 1960s and in 1967 became the founding chair of the world's first department of Clinical Epidemiology and Biostatistics. He held this position while contributing to the development of research methods through education, lectures, and publications. His work at McMaster included leadership in randomized clinical trials demonstrating the benefits of aspirin for patients with threatened stroke or heart attack, the value of carotid endarterectomy, and the effectiveness of nurse practitioners in primary care. Sackett later moved to the University of Oxford, where he served as Professor of Clinical Epidemiology and founded the Centre for Evidence-Based Medicine. He also co-edited the journal Evidence-Based Medicine and contributed to the establishment of the Cochrane Collaboration.
Sackett authored or co-authored more than 300 papers and 10 books, including Clinical Epidemiology: A Basic Science for Clinical Medicine (1985) and Evidence-Based Medicine: How to Practice and Teach EBM. His contributions transformed clinical research and medical practice worldwide. He received numerous honors, including appointment as an Officer of the Order of Canada, induction into the Canadian Medical Hall of Fame, the Gairdner Foundation Wightman Award, and fellowship in the Royal Society of Canada. Sackett also held clinical appointments, including Physician-in-Chief at Chedoke-McMaster Hospitals and Head of the Division of General Internal Medicine. He retired from clinical practice in 1999 and continued research and teaching until his death in 2015.