“…The incidence of delirium has been reported to range 20-30% in patients hospitalized in general wards (Juliebo et al, 2009;Mariz et al, 2013;McPherson et al, 2013;Sharma et al, 2012;Van Rompaey et al, 2009), 36-44% in elderly post-surgery patients (Juliebo et al, 2009;Robinson et al, 2009), and 32-87% in patients hospitalized in the intensive care unit (ICU) (Ouimet et al, 2007;Vasilevskis et al, 2012;Wells, 2012). Although the incidence of delirium in Korea has been reported as 22% in ICU patients and 10-32% in post-surgery elderly patients (Kang et al, 2011;Kim et al, 2008), an incidence of 26% in ICU patients was reported in a recent large-scale study reported (Moon et al, 2013). The higher incidence in ICU patients has been attributed to the nature of the ICU environment and the severity of the diseases for which ICU patients are treated (Inouye, 2006).…”