Reliability and Validity of a Japanese Version of the Dementia Behavior Disturbance Scale

Abstract

Since behavioral disturbance among patients with dementia is a great burden for their caregivers, quantification of behavioral disturbance is essential in determining disease severity and assessing the impact of the disease on caregivers. However, the method of its quantification for objective assessment is not established yet. We studied the reliability and validity of a Japanese version of the Dementia Behavior Disturbance Scale (DBD Scale) which was originally developed by Baumgarten et al. We also studied the relationship between DBD scores and the degree of burden felt by caregivers. Our subjects consisted of 27 cases with dementia (mean age 77.7 years), and 17 cases of patients with neurological disorders without dementia (76.8 years), and 10 institutionalized patients with dementia (82.3 years). The test-retest reliability, internal consistency, and inter-rater reliability were very good; the coefficient of correlation between DBD scores at the two interviews was 0.96, the coefficient of internal consistency was 0.95, and the intraclass correlation coefficient was 0.71±0.10. DBD scores correlated significantly with SPMSQ errors and caregivers' burden; r=0.54 and 0.53, respectively. Our results indicate that the DBD Scale is highly reliable, and may be useful for objective assessment of behavioral disturbance and caregivers' burden.