Delirium prevalence, risk factors and outcomes among patients with acute stroke: A multi-centre observational study

•A third of patients admitted to a stroke unit develop delirium, lasting an average of three days.•The episodes occur mainly on the first day of admission, when several risk factors may play a role.•At admission, higher scores in the National Institute of Health Stroke Scale evaluation might suggest which patients are at increased risk of delirium.•Patients with delirium report negative short-term outcomes such as higher mortality, higher functional dependency at discharge and a potential delay in being admitted to rehabilitation units. Delirium is a frequent and serious acute neuropsychiatric syndrome leading to worse prognosis including mortality. Patients with ischaemic and/or haemorrhagic stroke are vulnerable to delirium. However, predisposing and precipitating factors have not been fully discovered to date, leaving this area of practice under-represented in available guidelines. To describe the prevalence, associated factors and main in-hospital outcomes of post-stroke delirium. A multi-centre observational study was conducted from 2019 to 2020 and reported according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Data were collected in stroke units located in two large hospitals in the North-East region of Italy. Consecutive adult patients with ischaemic and/or haemorrhagic stroke with a Glasgow Coma Scale > 5, who were willing to participate, were included. Data at admission, during the in-hospital stay and at discharge were collected by trained nurses, not involved in the care of patients, with (a) validated tools, (b) direct observation, and (c) access of patients’ records. A total of 78 patients were enrolled (mean 73.1 years; 59% male), and 70.5% of them had suffered an ischaemic stroke. The mean National Institutes of Health Stroke Scale (NIHSS) at admission was 8.2 ± 7.0. A total of 34.6% of patients developed post-stroke delirium; the onset was mainly on the first day of admission (70.4%) and the condition lasted for an average of 3.7 days (SD 2.6). In the multivariate logistic regression, 64.1% of the delirium variance was explained by the NIHSS scores (RR 1.259, 95%CI 1.035–1.533; p = 0.022). Patients with post-stroke delirium reported higher functional dependence at discharge and the need for more delaying of hospital care to be admitted in rehabilitation units. At admission, higher scores in the NIHSS evaluation might suggest which patients are at an increased risk of delirium. Avoiding interventio