This is a 10-year observational study. The study will be performed in Occitania Region. Once a year, a complete data collection will be performed in the Gerontopole of Toulouse, in participants' home and health centers by the Gerontopole mobile research team, and in selected Gerontopole's collaborating centers in Occitania.

Between yearly waves of data collection, participants will have their intrinsic capacity domains monitored (with or without the help of a caregiver) each 4-month through the use of either an app developed in collaboration with World Health Organization (WHO) or a web platform; or through a phone call by a clinical/research nurse. For the first self-monitoring of IC at four months, all participants will be contacted by a research/clinical nurse by phone; this call will inform about how participants measured their capacity and/or help them to do it. After this first 4-month phone call, participants capable of correctly self-monitoring their IC through the app will no longer be systematically contacted by phone. Once IC declines are confirmed, participants will have a thorough clinical assessment and blood sampling; such information will allow us to investigate the response of markers of aging at the time declines are detected. Those needing usual care, will be followed according to WHO framework recommendations proposed for Integrated Care for Older Adults (ICOPE).