Del-IT study: delirium incidence and treatment in an acute palliative care unit – a prospective cohort study

Objectives To estimate the cumulative incidence of new-onset delirium in an acute palliative care unit (APCU) and to describe its clinical characteristics, management and outcomes. Methods The Del-IT study is a prospective observational cohort study, conducted in a 10-bed APCU, between January 2024 and March 2025. Consecutive admissions were prospectively screened for delirium three times per day using the Nursing Delirium Screening Scale, with diagnostic confirmation according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria and severity assessed using the Memorial Delirium Assessment Scale. Results Among 392 patients screened, delirium was confirmed in 168 (42.9%), and the cumulative incidence of new-onset delirium was 27.2%. Median age was 71 years, and most patients had advanced cancer (79.8%) and poor functional status (median Palliative Performance Scale 40). Mixed subtype predominated, and median severity was moderate. Treatment directed at delirium aetiology was implemented in 74 patients (44.0%); delirium reversed in 27 of those who received directed treatment (36.5%). Reversibility was associated with higher Palliative Performance Scale (p<0.05), better level of consciousness (p<0.001) and less severe delirium (p<0.001). Median survival from study inclusion was 7 days. Higher delirium severity independently predicted shorter survival (p<0.001). Conclusion Delirium is highly prevalent in the APCU setting and often persists despite treatment. These findings highlight the importance of systematic delirium. Delirium severity and trajectory may provide clinically useful prognostic information and support goal-concordant decision-making. Further prospective studies are required to determine the effectiveness of specific treatment strategies.