Clinical utility and validation of the Japanese version of Memorial Delirium Assessment Scale in a psychogeriatric inpatient setting.

Delirium is a common mental disorder in the elderly. The Memorial Delirium Assessment Scale (MDAS) was developed in 1997 to assess delirium severity over time. The purpose of the current prospective study is to assess the clinical utility, diagnostic potential, reliability and validity of the Japanese version of MDAS in a psychogeriatric unit setting. Reliability was examined by testing 37 elderly patients; validity was examined concurrently by 16 patients with delirium. Two psychiatrists evaluated each patient simultaneously. Mean MDAS ratings differed among groups of patients with delirium, dementia, or no cognitive impairment. High levels of consistency within raters (Cronbach's alpha=0.92) and reliability between raters (0.98) were indicated. The correlation between MDAS scores and rating on the Delirium Rating Scale (r=.74, P=.0011), the Clinician's Global Rating of delirium severity (r=.67, P=.0047), and the Mini Mental State Examination (r=-.54, P=.029) was fair. The MDAS seems to be a reliable measuring instrument for assessing delirium in elderly patients.