In a retrospective cohort of 12,866 hospitalizations of adults ≥65, delirium was independently associated with higher odds and counts of in-hospital falls (OR 1.51, IRR 1.47), with Parkinson's disease, male sex, and antipsychotic exposure also linked to falls and baseline functional status…

Low direct value for Parkinson's therapeutic discovery, but clinically relevant for PD care because preventing or managing delirium in hospitalized PD patients may reduce fall risk and related morbidity, suggesting targets for care-pathway interventions rather than molecular therapeutics.

PURPOSE: To examine the association between delirium and in-hospital falls in older adults, including fall occurrence and number of falls, and to assess whether fall-related factors differ according to delirium status. METHODS: We conducted a retrospective cohort study of patients aged ≥ 65 years hospitalized in acute geriatric units between 2022 and 2024. Delirium was identified using ICD-10 codes, Confusion Assessment Method (CAM) documentation, and physician-entered diagnoses. Fall occurrence (≥ 1 fall) was analysed using multivariable logistic regression and number of falls using negative binomial regression. Analyses were stratified according to delirium status. RESULTS: Among 12,866 hospitalizations, 1751 patients (13.6%) experienced at least one in-hospital fall. Delirium occurred in 2889 patients (22.5%) and was independently associated with fall occurrence (OR 1.51, 95% CI 1.32-1.72). Male sex (OR 1.56, 95% CI 1.39-1.74), Parkinson's disease (OR 1.52, 95% CI 1.23-1.89), and antipsychotic exposure were also associated with falls. Baseline functional status showed a significant interaction with delirium status (p = 0.0002): higher functional independence was associated with lower fall risk in patients without delirium (OR per 10-point FIM increase 0.91, 95% CI 0.89-0.94), but not in those with delirium (OR 0.99, 95% CI 0.95-1.03). Delirium was also independently associated with a higher fall count (IRR 1.47, 95% CI 1.31-1.66). CONCLUSION: Delirium is independently associated with both the occurrence and number of in-hospital falls. Once delirium develops, fall risk appears to reflect a state of acute neurocognitive instability in which baseline functional status loses much of its discriminative value for risk stratification.