A Standardization Study on the Korean Version of the Addenbrook's Cognitive Examination Revised (K-ACE) as a Cognitive Impairment Screening Instrument: Reliability, Validity and Normative Data

ABSTRACT

BACKGROUND: Addenbrooke's Cognitive Examination-Revised (ACE-R) is a brief but sensitive and specific test for screening cognitive impairment. The clinical need for brief, inexpensive, and sensitive cognitive screening tools is well acknowledged. The aims of this study were to develop a Korean version of the ACE-R (K-ACE) and to obtain normative data for community-dwelling, apparently healthy adults. METHODS: The ACE-R was translated and modified to produce the K-ACE. Some items that were considered less familiar to Koreans were replaced with "Korean-friendly" items. Back-translation was performed. The K-ACE was administered to 422 of 480 subjects who were recruited from stroke- and dementia-free adults living in Ansan-si, Gyeonggi-do, by systematic random sampling. The Korean version of the Short Blessed Test (SBT-K) was also completed by 85 of the subjects. We examined the internal consistency, reliability, and validity of the K-ACE. The influences of age, sex, and education level on K-ACE score were also evaluated. RESULTS: The internal consistency of the K-ACE was high (Cronbach's alpha=0.854), and the test.retest and interrater reliability were also very good (coefficient=0.929 and 0.984, respectively). The validity of the K-ACE was high through correlations between K-ACE and K-MMSE (r=0.939, p<0.01) and SBT-K (r=-0.871, p<0.01). Male, younger, and highly educated subjects had higher K-ACE scores on univariate analysis. Age and education level, but not sex, were significantly correlated with the score on stepwise multiple regression analysis. Therefore, normative data relative to age and education level were obtained. CONCLUSIONS: The K-ACE was found to be a brief, reliable, and valid screening test battery for cognitive dysfunction. We were able to determine the norms for the K-ACE for community-dwelling, middle-aged and elderly people.