Clinical validity of the Chinese version of Mattis Dementia Rating Scale in differentiating dementia of Alzheimer's type in Hong Kong.

The present study aimed to examine the clinical validity and applicability of the Chinese version of Mattis Dementia Rating Scale (CDRS) for elderly Chinese individuals. The scale was found to have good reliability with internal consistency ranging from 0.7 to 0.9. Its significant correlation with the Chinese version of Mini-Mental State Examination (CMMSE) suggested satisfactory construct validity of the scale. The discriminant validity of the CDRS in differentiating Alzheimer's disease (AD) patients and Normal Control (NC) elderly was also supported by the Receiver Operating Characteristics (ROC) analysis. Several cut-off points were presented for different clinical or research applications, and formulas to adjust for the age and educational level of the CDRS total score were provided. The Initiation/Perseveration and Memory subscales were suggested to be an abbreviated version of the CDRS for a quick screening. The present results also showed the association between the impairment of the CDRS performance and the progress of the AD.