“…The predominance of functional indicators in early studies was counterbalanced thereafter by the use of health indicators (physical and mental illnesses) (Collerton et al, 2009;Marengoni, Winblad, Karp, & Fratiglioni, 2008). Some tried to classify the oldest old in homogeneous groups according to their health and/or functional status (Cevenini et al, 2013;Gondo et al, 2006;Motta et al, 2005) and others to investigate the predictors of longevity (Dupre, Liu, & Gu, 2008;Edjolo et al, 2013;Ferrer et al, 2008;Robine et al, 2012;Tiainen, Luukkaala, Hervonen, & Jylha, 2013). In order to better understand the heterogeneity of situations in old age, Rowe and Kahn suggested to distinguish and value "successful ageing" from ageing with disability or in poor health (Rowe & Kahn, 1987).…”