The goal of this observational study is to evaluate the association between complexity and multiple illnesses of adult hospitalized internal medicine patient and mortality. The observational study will also evaluate the association between pre-existing factors at hospitalization and clinical outcomes such as mortality, length of hospital stay, intensity of care (transfer to units with higher clinical intensity), complications and rehospitalization.

For data collection, four index weeks will be identified during the year in which the participating Centers will have to sequentially enroll all the participants who will be admitted to the Internal Medicine units, until reaching, for each index week, 10 participants for each of the Participating Centers.

Each enrolled participant will undergo a 12-month follow-up. The study foresees the enrollment of 2326 participants.

Inclusion Criteria:

1. Patients of legal age (age >= 18 years).
2. Informed consent according to Italian law.

Exclusion Criteria:

• No specific exclusion criteria were identified.

adult hospitalized internal medicine patient