Study System. Healthcare Although the ancient hospitals intended for the reception and treatment of the sick and travelers arose in the city at least from the 8th century, the first Pavia hospitals serving the entire city of which documented traces remain are the hospital of Santa Maria in Betlem (attested from 1130) and that of San Lazzaro (1157), which were operational for centuries. After 1449, they ceded their primary role to the San Matteo Hospital which became one of the most important Pavia institutions. The ancient dedication to San Matteo is still carried by the San Matteo Polyclinic, whose full name is the Fondazione IRCCS Policlinico San Matteo Hospital. In addition to Policlinico San Matteoo Hosital, Pavia has five hospitals, including public and affiliated, specialist or general hospitals that cover the pathologies provided for by national protocols. Patients from other regions often resort to them. Among the hospitals, there are several that belong to the category of scientific hospitalization and treatment institutes, the so-called IRCCS. We recall, among the specialized ones, the Casimiro Mondino National Neurological Institute and the Maugeri Scientific Clinical Institute, while among the general hospitals the most important are the Institute of Care of the City of Pavia and the Santa Margherita Institute of Rehabilitation and Care. In addition, Pavia hosts the National Center for Androtherapy Oncology (CNAO Foundation), the first hospital and clinical and radiobiological research in the center in Italy (the fourth country in the world to set up one). It was set up in 2010 by the Ministry of Health and specializes in the treatment of radioresistant tumors through the use of particle therapy. The Center also carries out scientific research to identify effective tools in the fight against cancer. The CNAO uses a synchrotron where particles are produced in two sources, these are pre-accelerated by a linear accelerator and sent to an injection line for transfer into the synchrotron ring, where they are further accelerated and extracted. Demographics Starting from the 80s of the twentieth century Pavia has undergone a notable demographic involution due to the transfer of many families within the municipalities immediately bordering the capital. Within the urban agglomeration of the city of Pavia, according to calculations made by applying the international criterion of Functional Urban Areas, approximately 121,000 inhabitants would reside. Ethnic groups According to the latest statistics conducted by ISTAT, approximately 14.54% of the population consists of non-Italians. About