This is the second edition of a well received book that reviews classical epidemiological and clinical research designs, with a specific focus on aging. Chapters cover basic topics like the scientific method, ethics, and the consequences of certain exclusion criteria. The work also includes a look at clinical concepts like multimorbidity, frailty and functionality. New material includes chapters such as geroscience, health systems research, big data and data mining, financing and future of aging research. The authors reveal the issues and challenges for researchers of age and aging, and...