Aim: The SKT (Syndrom Kurztest) is a short cognitive performance test that consists of nine subtests and assesses deficits of memory and attention. It was aimed at exploring the SKT target population in China and to evalute the reliability and validity of the Chinese version of SKT.
Method: A total of 1624 patients (599 cognitively normal controls, 359 subjectively cognitively impairment, 666 individuals with mild cognitive impairment) aged over 60 years old were recruited in the Sixth People’s Hospital in Shanghai. Cognitive screening tests (Chinese version of SKT, MMSE, MoCA-BC, ACE-III, AVLT, BVMT-R) and global functional tests (ECOG, ADL) were carried out. The SKT raw scores were recorded. Cronbach’s alpha coefficient was determined to assess the internal consistency reliability of the SKT. Principal factor analysis was performed to evaluate the factor structure of the SKT subtests. Correlation analyses were carried out to confirm the relationship between the modified SKT and standardized neuropsychological tests. The influence of age and educational years on SKT raw scores were detected using multiple regression analyses. Validations of the SKT subtests for detecting MCI from NC were determined by Receiver operating characteristic (ROC) curves.
Result: The internal consistency among the subtests’ scores was high: Cronbach’s α=0.827. The dimension reduction analysis showed the good factor structure of SKT subtests. Correlation analysis indicated the SKT raw scores of each subtest was negatively correlated with the corresponding MMSE and MoCA-B score. Correlation analysis revealed that age and education years were correlated to SKT raw scores (all p <0.001). We separated the participants into four subgroups according to educational years and age. Among the four groups, The old-old with higher educational level (group 4) had the largest area under the ROC curve (AUC) for SKT memory test, 0.821(95%CI: 0.747,0.876), with sensitivity 84.3% and specificity 62.1%. SKT memory test provided a high predictive validity in detecting aMCI with sensitivity 90.1% and specificity 79.3%.
Conclusion: Based on our experience with 1624 old patients in Shanghai, the Chinese version of SKT has good stability which might be a reliable and valid screening tool for detecting MCI. However, test results must be interpreted with caution considered individuals’ age and educational level.