The article offers the reflection-provocation of a working group with various roles and competences on a wide range of experiences (observational studies in general medicine, epidemiological analyses or large administrative databases, control and evaluation of the effectiveness and safety of treatments) on populations of ever-more-aged-old-people in home and/or residential contexts. Starring from the ambiguity of the relation between medicine and an ageing society the authors offer some concrete interpretations of health data relating to expenditure on drugs, hospital costs and care services. The distribution-fragmentation of the apparently compact world of the old, in populations or cohorts that were extraordinarily different in clinical gravity, care burden, life contexts and complexity, seems to be a necessary condition for researchers able to attend to the multiple paths or the lives of the elderly.