ENO2 and delirium: Another study determined that a neuron specific enolase concentration >12.5 μg/L was independently associated with a 23.3% (95% CI 6.7–39.9, P = .006) increased risk of 30-day mortality and a 29.3% (95% CI 8.8–49.8, P = .005) increased risk of delirium [65].