Background: Delirium is a serious and common condition that needs an upgrade of the scientific and clinical attention.

Aim: To assess the delirium prevalence in an Italian university hospital.

Methods: The monocentric 1-day observational study cohort has been conducted on March 15, 2018; the population was composed of adult hospitalized patients. All the eligible patients have been evaluated for the presence of delirium with the 4AT.

Results: We enrolled 596 patients. Twenty-nine Acute and 3 Rehabilitation Units were involved in the study. The median age of the sample was 60 (IQR 48-74) and 52% (n = 313) were male. Patients from medical units were 42% (n = 252), from surgery units 41% (n = 249), and from rehabilitation units 15% (n = 95). Results of 4AT showed that 5.4% (n = 32) had delirium (4AT = 4), 12% (n = 73) had cognitive impairment (4AT = 1-3), and 82% (n = 491) had no delirium or cognitive impairment (4AT = 0). We found association between delirium and age, BMI, mortality at 30 days, and hospital mortality. Delirium was related with Barthel Index, dementia, and anticholinesterase inhibitors. About devices in use, we observed a correlation of delirium with central venous catheter, feeding tube, and urinary catheter. Physical restraints were also correlated to delirium.

Conclusions: We confirmed the presence of delirium across the hospital units, more in medical than in surgical ones. We found associations of delirium with conditions that limit movement, such as dementia, physical restraints, or devices. The development of delirium initiates a cascade of events culminating in the loss of independence and increased morbidity.