Data collection
delirium, agitation, cognitive impairment
Clinical data were collected retrospectively by reviewing medical records. The presence of delirium was estimated based on the following three criteria: a medical report of delirium, the presence of an episode of agitation, and/or prescription of antipsychotic/neuroleptic treatment during admission. To assess pre-existing cognitive impairment, the relatives of patients ≥ 65 years old completed the Spanish Version of the Short Form of the Informant Questionnaire on Cognitive Decline in the Elderly (Short-IQCODE) [