2327 Delirium predicts poor outcomes in Parkinson's disease

Abstract Introduction Reported delirium prevalence in inpatients with Parkinson’s disease (PD) varies widely across the literature and is often underreported. Delirium is associated with an increased risk of institutionalisation, dementia, and mortality, but to date there are no comprehensive prospective studies in PD. We aimed to determine delirium prevalence in PD compared to older adults and its associated risk with adverse outcomes. Method Participants from the ‘Defining Delirium and its Impact in Parkinson’s Disease’ (DELIRIUM-PD) and the ‘Delirium and Cognitive Impact in Dementia’ (DECIDE) studies were included. People with PD (DELIRIUM-PD) or older adults from the Cognitive Function and Ageing Study II – Newcastle cohort (DECIDE) admitted to hospitals in Newcastle were approached to take part. Delirium was assessed prospectively using the Diagnostic and Statistical Manual of Mental Disorders – 5th Edition criteria. Outcomes were determined by medical note reviews and home visits 12 months post discharge. Cox regression or binary logistic regression were used to evaluate the effect of delirium on institutionalisation, dementia, and mortality, independent of covariates. Results Delirium developed in 66.9% (n = 81/121) of PD participants compared to 38.7% (n = 77/199) of controls (p < 0.001). Delirium was associated with a significant increased risk of developing dementia in one year in PD (OR = 6.1 (1.3–29.5), p = 0.024) and in controls (OR = 13.4 (2.5–72.6), p = 0.003). However, in only PD participants, delirium was associated with a significantly higher risk of institutionalisation (OR = 10.7 (2.1–54.6), 0.004) and mortality (HR = 3.3 [95% CI 1.3–8.6], p = 0.014). Conclusion This is the first comprehensive prospective study of delirium in PD, showing that over two-thirds develop delirium during hospitalisation compared to a third of older adults. Delirium in PD is associated with a significant risk of dementia, institutionalisation, and death in one year. Furthermore, this is the first study to show that PD increases the risk of mortality and institutionalisation over and above a delirium in older adults.