CHI3L1 and delirium: Among the patients <i>without</i> dementia, those with delirium had higher median concentration of CSF YKL-40 compared with those without delirium (first cohort: 175 versus 132 ng/mL, <i>P</i> = 0.01, second cohort: 243 versus 174 ng/mL, <i>P</i> < 0.001).