Validation of the Severe Impairment Battery for patients with Alzheimer's disease in Korea.

OBJECTIVE: To examine the reliability and the validity of the Korean version of the SIB (SIB-K); and to determine its usefulness in patients with severe dementia.

METHODS: Sixty-five patients (56 women, nine men) who lived in a nursing home and met the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edn, for the dementia of the Alzheimer's type were selected. Following clinical examination and evaluation using the Korean version of the Severe Impairment Battery (SIB-K), the Korean versions of the Mini-Mental State Examination (MMSE-K) and the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-K-cog) were applied as comparators.

RESULTS: The mean scores on the SIB-K were 63.9 (SD = 29.1), with a possible maximum of 100 points. Patients with MMSE scores from 0 to 4 points showed wide range of the SIB score from 4 to 62. The internal consistency of the SIB-K obtained by the Cronbach's alpha was 0.98. The inter-rater and test-retest reliabilities of the SIB-K obtained by the Spearman's rho were 0.99 and 0.97, respectively. Correlation between the SIB-K and the MMSE-K was 0.87, while correlation between the SIB-K and the ADAS-K-cog was -0.76.

CONCLUSIONS: This study indicates that the Korean version of the SIB is a reliable, valid and useful test for measuring cognition of severely demented patients at a point where other conventional tests lose their sensitivity and show a floor effect.