Using quantile regression (table 2), we found no difference in CSF Ng concentrations between hip fracture patients with and without delirium with median (IQR) 176 (134–235) versus 164 (130–219), with an estimated difference in medians of 12 (95% CI −5.8 to 29.8), p=0.185. Here, NRGN is linked to delirium.