A study of the reliability and validity of the Chinese version of the Dementia Rating Scale

Background: The present study aims to develop and validate a Chinese version of the Dementia Rating Scale (DRS) for use with Chinese populations in psychogeriatric settings. Methods: The DRS was translated into Chinese and its content validity was evaluated by an 11-member expert panel. To assess reliability and concurrent validity, 52 subjects with dementia were recruited from medical and psychogeriatric settings using purposive sampling. Results: With percentage of agreement as an indicator, 28 out of 36 items (78%) had satisfactory content validity. Items with a percentage of agreement below 70% were reviewed and modified, based on the comments of the experts. The CDRS had excellent test-retest and inter-rater reliability, with intraclass correlation coefficient (ICC) at 0.94 and 0.93 respectively. Intraclass correlation coefficients ranged between 0.75 and 0.89 for the subscales. The internal consistency of the CDRS subscale, as measured by Cronbach's alpha, ranged from 0.57 to 0.82. The CDRS had high correlations with the Chinese Mini-mental State Examination (r = 0.80 for total score, r = 0.58 to 0.84 for subscales. Conclusions: The CDRS is a valid instrument for the assessment of dementia in Chinese-speaking subjects.