National Age- and Education-Specific Normative Data for K-MoCA Total Score, Domain Index Scores, and K-MoCA-22.

Background and Purpose: The Korean-Montreal Cognitive Assessment (K-MoCA) is widely used for cognitive screening, but its normative data require updating to reflect current demographic characteristics. Norms are also unavailable for the K-MoCA domain index scores and the K-MoCA-22. This study aimed to update norms for the K-MoCA total score and to establish norms for the six domain index scores and the K-MoCA-22. Methods: A nationwide normative sample of 1,177 cognitively healthy adults aged 19-90 years completed the K-MoCA and the Korean-Mini Mental State Examination, Second Edition: Standard Version (K-MMSE~2:SV). Six domain index scores and K-MoCA-22 scores were derived from the K-MoCA. Demographic effects and score distributions were examined. Ordinary least-squares regression modeled the K-MoCA and K-MoCA-22 scores, while quantile regression modeled the domain index scores. Results: K-MoCA and K-MoCA-22 performance was primarily influenced by age and education, with sex contributing little independent variance. Compared with the K-MMSE~2:SV, the K-MoCA showed a broader score distribution and a smaller ceiling effect. Among domain index scores, the Memory Index Score showed the broadest distribution and the smallest ceiling effect. The K-MoCA-22 showed improved distributional characteristics relative to the K-MoCA, with reduced negative skewness. Age- and education-specific norms were established for all measures. Conclusions: This study provides updated age- and education-adjusted norms for the K-MoCA, along with the first Korean norms for its domain index scores and the K-MoCA-22. These norms extend the K-MoCA's clinical utility by enabling age- and education-adjusted interpretation of global and domain-specific cognitive performance in clinical practice and research.