The Incidence of Recorded Delirium Episodes Before and After Dementia Diagnosis: Differences Between Dementia With Lewy Bodies and Alzheimer’s Disease.

Abstract:

OBJECTIVES: To describe the incidence of delirium recording before and after a diagnosis of dementia is established in patients with dementia with Lewy bodies (DLB) and compare findings to a matched cohort of patients with Alzheimer's disease (AD). DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: A cohort of patients with dementia from a large mental health and dementia care database in South London, linked to hospitalization and mortality data. We identified 194 patients with DLB and 1:4 matched these with 776 patients diagnosed with AD on age, gender, and cognitive status. MEASURES: We identified delirium episodes recorded in mental health and hospital records from 1 year before to 1 year after dementia diagnosis. Using dementia diagnosis as an index date we additionally followed patients until first episode of delirium, death or a censoring point without restricting the observation period. RESULTS: Patients with DLB had significantly more episodes of delirium recorded in the year before dementia diagnosis than patients with AD (incidence rate 17.6 vs 3.2 per 100 person-years; P