Constructing a Composite Score for the Seoul Neuropsychological Screening Battery-Core

ABSTRACT

BACKGROUND AND PURPOSE: The brief version of the Seoul Neuropsychological Screening Battery (SNSB), the SNSB-Core (SNSB-C), has been developed. Although each subtest score of the SNSB-C provides information on different features of broad cognitive functioning or impairment, a composite score is needed to identify the severity of global cognitive impairment. We aimed to develop and validate a composite score of the SNSB-C that would provide a normative-based summary score of global cognitive functioning, especially for differentiating patients with cognitive impairment from normal elderly. METHODS: A normative sample of 1067 elderly was used to develop a composite score of SNSB-C. The composite score was corrected for the effects of age, years of education, and sex by the regression method. Patients with Alzheimer's disease (n=41), vascular dementia (n=40), amnestic mild cognitive impairment (MCI) (n=73), vascular MCI (n=41), and Parkinson's disease with MCI (n=41) were differentiated from a normal sample (n=70) by the uncorrected and corrected composite scores using receiver operating characteristic (ROC) curve analysis. RESULTS: Confirmatory factor analysis showed that the composite score equal weight to each standardized cognitive domain of SNSB-C is appropriate for indexing overall cognitive functioning. The corrected and uncorrected composite scores yielded a satisfactory size of the area under the ROC curve comparable to the Mini Mental State Examination (MMSE). CONCLUSIONS: The composite scores of SNSB-C, especially the corrected score, provide an index of overall cognitive functioning, and they can be used as an alternative to MMSE for screening patients with cognitive impairment.