LAUSR

To investigate aetiology-specific associations with mortality among older patients with delirium. Delirium predicted mortality, as did inflammatory and metabolic disorders. However, there was no evidence for any interactions between these factors. Mortality from delirium is consistent regardless of underlying aetiology, suggesting that no aetiology carries better or worse prognosis than another. To describe aetiology-specific associations with mortality among older hospital patients with delirium. Over 21 months, a cohort of 1702 patients with 2471 acute hospital admissions (median age 85, IQR 80–90, 56% women) were assessed for delirium, categorised with inflammatory and metabolic aetiologies based on available laboratory results, and followed up for all-cause mortality. Interactions between aetiology and delirium were tested. The total mortality for the cohort was 35.2%. While inflammation, metabolic disturbance, and delirium at time of admission all demonstrated independent associations with mortality, there was no evidence for any interactions between delirium and these laboratory-measured aetiologies. Delirium remains an important predictor of death in older hospital patients, irrespective of underlying aetiology.