editors-in-chief, Jan Busby-Whitehead, MD, CMD, AGSF, is Mary and Thomas Hudson Distinguished Professor and Chief, Division of Geriatric Medicine, and Director, Center for Aging and Health, University of North Carolina, Chapel Hill, Christine Arenson, MD, is Professor and Interim Chair, Department of Family and Community Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, and Co-Director, Jefferson Center for Interprofessional Education, Thomas Jefferson University ; editors, Samuel C. Durso, MD, MBA, AGSF, is Mason F. Lord Professor of Medicine and Director, Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Daniel Swagerty, MD, MPH, AGSF, is Associate Professor, Department of Family Medicine, and Associate Director, Landon School on Aging, University of Kansas School of Medicine, Laura Mosqueda, MD, AGSF, is Chair, Department of Family Medicine, Professor of Family Medicine and Geriatrics (Clinical Scholar) and Associate Dean of Primary Care, Keck School of Medicine of the University of Southern California, Maria Fiatarone Singh, MD, is John Sutton Chair of Exercise and Sports, and Professor of Medicine, Sydney Medical School, University of Sydney ; editor emeritus, William Reichel, MD, AGSF, is Affiliated Scholar, Pelligrino Center for Clinical Bioethics, Georgetown University Medical Center. -- Cambridge University Press, -- 2016. -- Seventh edition.