title: Understanding frailty.
authors.forename: Walter
authors.initials: W
authors.lastname: Bortz
mesh_terms: D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D035843:Biomedical Research; D016330:Frail Elderly; D005853:Geriatrics / Q000379:methods*; D006801:Humans; D012955:Societies, Medical; D014481:United States