Predicting Delirium Risk in Older Adults Requiring Emergency Hospitalization: Clinical Utility of the Noise Pareidolia Test

AIM: Delirium is a serious complication in older patients requiring emergency hospitalization. The noise pareidolia test (NPT), originally developed to evaluate visual hallucinations, may serve as a novel screening tool for visual-perceptual vulnerability associated with delirium risk. This study aimed to clarify whether the NPT score is a clinically useful independent predictor of delirium in older adults requiring emergency hospitalization. METHODS: This secondary analysis used data from a prospective cohort study conducted at an acute-care hospital in Japan. A total of 57 older adults (≥ 65 years) who were urgently admitted and met the inclusion criteria were analyzed. The relationships between NPT scores, Mini-Mental State Examination (MMSE) scores, use of benzodiazepine receptor agonists (BZD), and delirium onset were examined using multivariate logistic regression analysis. The predictive performance of the NPT was evaluated using receiver operating characteristic (ROC) curve analysis. Delirium was assessed using the delirium screening tool (DST). RESULTS: The median NPT score was significantly higher in the DST-positive group than in the DST-negative group. Logistic regression analysis revealed that the NPT score was the only independent predictor of delirium. ROC analysis showed moderate discriminatory ability, with an optimal cutoff value of 2.5, sensitivity of 60.9%, and specificity of 67.6%. CONCLUSION: The NPT score was significantly associated with delirium onset and was identified as an independent predictor among older patients requiring emergency hospitalization. The NPT may serve as a simple, non-invasive bedside screening tool for the early identification of high-risk patients in clinical nursing practice.