The<unk>  or patient zero is the first documented patient in a disease epidemic within a population, or the first documented patient included in an epidemiological study. It can also refer to the first<unk>  of a condition or syndrome (not necessarily contagious) to be described in the medical literature, whether or not the patient is thought to be the first person affected. An<unk>  can achieve the status of a "classic"<unk>  study in the literature, as did Phineas Gage, the first known person to exhibit a definitive personality change as a result of a brain injury.
Index case
Sun Hudson case
Jahi McMath case
Real world data
Exposure hierarchy
Diagnosis-related group
Retrospective diagnosis
History of Modern Biomedicine Research Group