Our systematic review identified 12 studies that investigated S100β serum concentration as a predictor for delirium during hospitalization, eight of which controlled for illness, and six out of these eight controlled for cognitive impairment before hospitalization (8, 21, 25, 28, 31, 34, 36, 59, 61, 63, 64, 66). Here, S100B is linked to Cognitive impairment.