Prevalence and risk factors of delirium and subsyndromal delirium in Chinese older adults.

Aim: To study the prevalence and risk factors of delirium and subsyndromal delirium (SSD) in Chinese older adults with acute medical illnesses.

Methods: A prospective cohort study was carried out in acute general medical wards in a university-affiliated hospital in Hong Kong. Patients were assessed by the confusion assessment method by geriatricians within 6 h after admission and classified into three mutually exclusive groups, namely delirium, SSD and those without both conditions.