Fig. 1.

Screening protocol for pre-existing cognitive impairment by surrogate assessment. ^a The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) is a 16-item, informant-based screening tool [31]. IQCODE scores from 3.3 to 3.6 have been shown to be valid for the diagnosis of dementia in a variety of non-ICU settings [4]. ^b The Clinical Dementia Rating Scale (CDR) is a detailed surrogate-based questionnaire designed to detect and stage dementia and commonly used as a gold standard. Because the main aim of the BRAIN-ICU study was to identify potentially modifiable risk factors for long-term cognitive impairment after the ICU, patients with severe dementia (CDR score = 3) were excluded.