Objective
To establish and evaluate the validity of the recently developed Korean version of the Oxford Cognitive Screen (K-OCS), this study verified its reliability, validity, and diagnostic accuracy.
Methods
Between November 2021 and December 2023, we recruited 72 patients with stroke from our hospital who agreed to participate in the study. The patients were repeatedly tested using K-OCS by the same or different assessors to estimate inter- and intra-rater reliability. To demonstrate the validity and usability of K-OCS, the test results of screening tools currently used in clinical practice, including the Korean-Mini Mental State Examination and the Korean version of the Montreal Cognitive Assessment, were used in comparison analyses.
Results
The subtests of K-OCS demonstrated excellent inter-rater reliability (intra-class correlation coefficient [ICC]=0.914–0.998) and test–retest reliability (ICC=0.913–0.994). We found moderate-to-strong correlations for convergent validity for the subsets (r=0.378– 0.979, p<0.01), and low-to-moderate discriminant validity correlations. The optimal cut-offs estimated for the subtests of the K-OCS showed a good-to-high range of specificity (94.8%– 100%). The positive predictive value was 58.2%–100% and negative predictive value was 65.6%–98.4%. Sensitivity was estimated at 25.6%–86.9%.
Conclusion
The results of this study indicate that K-OCS is a reliable and valid tool for screening cognitive impairment in patients post-stroke.