Recovery and outcome of delirium in elderly medical inpatients.

This study investigates the relationships between delirium, cognitive impairment and acute illness severity with adverse clinical outcomes; in-hospital mortality, hospital length of stay, or new entry to a care home. It is a prospective observational study of medical inpatients 70 years or older, with repeated measurements of cognition, delirium status, delirium severity, and severity of physical illness every 3 days until the 18th day and then the 28th day of hospitalization. Of 94 participants, 33 had delirium and 14 recovered during their hospitalization. Predictor variables for recovery were initial Mini Mental State Examination (MMSE) (p=0.003) and severity of delirium at second assessment (p=0.02), for mortality initial MMSE (p=0.002) and for discharge to care home were initial delirium status (p=0.008) and age (p=0.004). Delirious people newly discharged to care homes stayed longer in hospital than those discharged to their previous address (p=0.016). We conclude that delirium is not a transient disorder. The presence of delirium was not related to measures of the severity of physical illness or disability. High mortality was associated with delirium but was specifically associated with cognitive impairment. Prolonged length of stay of delirious people may depend on discharge destination.