Abstract: Objective To develop a simple delirium screening scale, and to investigate its reliability and validity. Methods The Diagnostic and Statistical Manual of Mental Disorders-fifth edition(DSM-V) was used as the gold standard for delirium. The item response theory(IRT) method was used to accurately portray and analyze the characteristics of each entry of the survey data, and the opinions of the expert panel were combined to form an ultra-simplified scale, which could be used to rapidly screen delirium for multiple. Finally, 359 patients who were admitted to the Geriatrics Center of West China Hospital from January to December 2023 were enrolled in this study to verify the reliability and validity of the scale. Results The completion rate of this study was 100%. According to DSM-V standard, the sensitivity of the Chinese Delirium Screen-Ultra Brief Scale(CDScreen-UBS) was 95.9%, the specificity was 83.5%, the positive predictive value was 48.0%, the negative predictive value was 99.2%, the positive likelihood ratio was 5.81, the negative likelihood ratio was 0.04, and the area under the receiver operating characteristic (ROC) curve was 0.897. Conclusions CDScreen-UBS is extremely sensitive in rapidly screening delirium in the elderly population.

Key words: delirium, simple screening tool, reliability, validity