A study in which researchers observe the “natural history” of a patient’s disease according to routine clinical practice (standard of care), including diagnostic procedures and therapeutic interventions. Differently from interventional studies, the standard of treatment provided to the patient is not modified during participation in the study. Data on standard therapy and its outcomes, as well as information on other patients and on the disease, are collected during the study to evaluate the association between outcomes and treatment and patient-related characteristics. This kind of study is also called non-interventional or non-experimental.