[Psychometric Properties of the Alzheimer's Disease Knowledge Scale--Korean Version]

Purpose: The purpose of this study was to evaluate the psychometric properties of the Korean version of the Alzheimer's Disease Knowledge Scale (ADKS-K) to determine its applicability to Korean adults.

Methods: Cross-cultural validity was performed according to Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). The Kuder-Richardson Formula 20 for internal consistency and Intraclass Correlation Coefficient (ICC) for test-retest reliability were conducted. Content validity, criterion related validity and construct validity were evaluated. The Classical Test Theory (CTT) model and the Item Response Theory (IRT) model were applied in performing the item analysis.

Results: The KR 20 was .71, and the ICC was .90, indicating that the ADKS-K has internal consistency and stability reliability. Thirty items of the ADKS-K had significant Content Validity Ratio (CVR) values, i.e., mean of 0.82 and range of 0.60~1.00. Mean item difficulty and discrimination indices calculated by TestAn program were 0.63 and 0.23, respectively. Mean item difficulty and discrimination indices calculated by BayesiAn program were -0.60 and 0.77, respectively. These tests indicate that ADKS-K has an acceptable level of difficulty and discriminating efficiency.

Conclusion: Results suggest that ADKS-K has the potential to be a proper instrument for assessing AD knowledge in Korean adults.