Delirium is not associated with mortality in elderly hip fracture patients

Abstract

Background: The relationship between delirium and mortality remains obscure. The aims of this study were to investigate the effect of delirium and the interaction between delirium and chronic cognitive impairment on mortality in elderly hip fracture patients.

Methods: This is a prospective observational study, including 331 hip fracture patients. Information on comorbidity, medications and clinical findings was collected at the time of fracture. Information on cause and time of death was obtained from the Norwegian Cause of Death Register. Patients were screened for delirium by the Confusion Assessment Method.

Results: Delirium was not associated with mortality when adjusting for the severity of chronic cognitive impairment, measured by the Infor- mant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Estimated by Kaplan-Meier plots, delirium in patients with dementia was significantly associated with an increased risk of death from stroke (p = 0.004) and dementia (p ≤ 0.001).

Conclusions: No association between delirium and mortality was demonstrated when adjusting for the IQCODE score, but delirium in patients with prefracture dementia was associated with an increased risk of death from stroke and dementia. The effect of delirium on the cause of death might be explained by an aggravation of an ongoing neuro-inflammation.