Validation of Korean Version of the Oxford Cognitive Screen (K-OCS), a Post Stroke-Specific Cognitive Screening Tool.

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.