A Normative Study of the Disability Assessment for Dementia in Community-Dwelling Elderly Koreans

ABSTRACT

OBJECTIVE: We investigated demographic influences on Korean version of Disability Assessment for Dementia (DAD-K) performance and developed normative data for DAD-K. METHODS: The DAD-K was administered to 2362 normal controls (NCs), 296 patients with mild cognitive impairment (MCI) and 293 patients with Alzheimer's disease (AD). MANOVA and ROC curve analysis were used to compare DAD-K performance and the diagnostic accuracy of DAD-K, respectively. The demographic influence on DAD-K scores was analyzed by multiple linear regression and ANOVA. Normative DAD-K data were calculated using natural logarithmic transformation. RESULTS: All DAD-K scores were significantly different among groups (p<0.001). Post hoc analysis showed that instrumental activities of daily living (IADL), executive function and DAD-K total scores began to decline significantly in the very mild stage of AD, whereas the basic activities of daily living (BADL) scores began to decline in the mild stage of AD. The area under the ROC curve differentiating MCI or AD from NC was 0.737 and that differentiating AD from MCI or NC was 0.911. IADL and planning and organization scores were influenced by age and education and performance and DAD-K total scores were influenced by education. CONCLUSION: The demographic influences on DAD-K scores are not conspicuous and are mainly limited to the IADL and planning and organization scores. Unitary or minimally stratified norms for a specific population were developed for DAD-K application. Our results suggest that the DAD-K is useful for differentiating NC or MCI from AD but not as powerful for differentiating NC from MCI.