The Validity of the Korean Version of Global Deterioration Scale

ABSTRACT

BACKGROUND: Clinicians broadly accept the Global Deterioration Scale (GDS) as a staging measure for dementia. The aim of this study is to test the inter-rater reliability and concurrent validity of the Korean version of GDS. METHODS: Participants included 34 subjects without dementia and 41 patients with Alzheimer's disease, in addition to 37 patients with vascular dementia. A rater, using a semi-structured clinical interview, interviewed the participants and their informed collateral sources. To obtain the concurrent validity, all participants received the Korean Mini-Mental State Examination (K-MMSE), the Korean version of Syndrome Kurz Test (K-SKT) and a 15-items abbreviated Korean-Boston Naming Test (K-BNT) on the same day. We also tested the inter-rater reliability among the four raters using a videotape design. RESULTS: The agreements of the overall GDS ratings by the four raters were high (kappa, 0.93-1.0). GDS correlated significantly with K-MMSE, K-SKT, and the abbreviated K-BNT and Clinical Dementia Rating scale. CONCLUSION: The Korean version of GDS may be a reliable and valid tool to be used as a staging measure for Korean patients with Alzheimer's disease as well as vascular dementia.