“…23 Altered mental status is reported in several studies to occur in as high as »50% of patients 65 y and older. 23,25,28,29 Other studies reported altered mental status in 12-17% in patients aged 65 y and older 17,20,22 and 21-26% in patients 85 y and older. 20,22 The variability, at least in part, can be explained by various definition of "altered mental status" (Table 2).…”