Validation of the Chinese version of the NUCOG cognitive screening tool in patients with epilepsy, dementia and other neurological disorders

We aimed to develop and validate a Chinese version of the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG) for use in Chinese-speaking subjects internationally. Patients and healthy controls were recruited from two hospitals between July and October 2012. Receiver operating characteristic (ROC) curves were utilized to test criterion validity. Convergent validity was assessed via correlations between NUCOG and the Mini-Mental State Examination (MMSE). Reliability was measured by internal consistency (Cronbach's α). Patients with epilepsy (n=144), neurological diseases (n=81), dementia (n=44), and controls (n=260) completed the NUCOG and the MMSE. Overall, both NUCOG and MMSE scores differed significantly across the four groups with the highest scores in the control group and the lowest in the dementia group (p<0.0001). The NUCOG scores could differentiate between patients with certain seizure types, stroke and transient ischemic attack. Compared to the MMSE, the NUCOG exhibited a higher area under the ROC curve. The convergent validity was substantially correlated, and internal consistency was very high (0.922). The Chinese version of NUCOG was demonstrated to be a sensitive and reliable screening tool for cognitive impairment in a Chinese-speaking population not only in China, but also in countries where there is a sizeable population of ethnic Chinese. Additionally, our study also showed the NUCOG could better differentiate cognitive function in patients with certain seizure types, stroke and transient ischemic attack than the MMSE. This potentially expands the clinical usefulness of NUCOG, enabling clinicians to measure the cognitive profile of patients with epilepsy and ischemic cerebrovascular diseases.