Age, gender, education, marital status, chronic obstructive pulmonary disease, pneumonia, stroke, hypertension, diabetes mellitus, cancer, angiotensin-converting enzyme inhibitor, losartan, atenolol, digoxin, hydrochlorothiazide, simvastatin, metoclopramide, ranitidine, omeprazole, tramadol, dipyrone, paracetamol, acetylsalicylic acid, prednisone, hydrocortisone, insulin, heparin, marevan, ciprofloxacin, levofloxacin, amoxicillin with clavulanate, spirolactone, furosemide, hydralazine and benzodiazepine had no association with the presence of delirium. The gene discussed is ACE; the disease is delirium.