Defining Aging Phenotypes and Related Outcomes: Clues to Recognize Frailty in Hospitalized Older Patients. - Marcucci, Maura; Franchi, Carlotta; Nobili, Alessandro; Mannucci, Pier Mannuccio; Ardoino, Ilaria; REPOSI Investigators (Journals of Gerontology Series A: Biological Sciences & Medical Sciences, 2017)