Developing a Chinese quality of life in dementia instrument for patients with early-to-moderate dementia: An exploratory test of validity

Aims: The purpose of this study was to examine the psychometric properties of the Chinese Dementia Quality of Life instrument, which included testing the different pathways through theoretical quality of life domains (self-esteem, feelings of belonging and sense of aesthetics) to reach outcomes of positive and negative affect. Background: Perceived quality of life in dementia has been conceptualised based on dementia stages. However, the relationships among quality of life domains are unclear in patients with dementia with a Mini-Mental State Examination >10. Design: Cross-sectional study. Methods: Older people (n = 110) were consecutively recruited from memory disorder clinics and community wellness centres (controls). Of these participants, 27 were controls, 39 were diagnosed with questionable dementia and 44 with mild-to-moderate Alzheimer's disease. The instrument was back translated and validated. Results: The instrument has good overall internal consistency (Cronbach's alpha = 0·84-0·94). Item-total correlation coefficients, indicating construct validity, were all significant, except for one item. anova showed that controls, patients with questionable dementia and those with mild-to-moderate Alzheimer's disease differed significantly in scores on Sense of Aesthetics subscale. Instrument total score and scores on three of five subscales (not Feelings of Belonging) differed significantly between control and dementia groups, but not between patients with questionable dementia and those with mild-to-moderate Alzheimer's disease. Factor analyses showed two inconsistencies with the instrument's prior conceptualisation, namely the Self-Esteem and Negative Affect subscales. The Positive Affect path model was supported but not the Negative Affect path model. Conclusions: This patient-reported Dementia Quality of Life instrument has acceptable psychometric properties in Taiwanese patients with dementia with a Mini-Mental State Examination score >10. Relevance to clinical practice: The Chinese Dementia Quality of Life instrument can be used to assess subjective quality of life in Taiwanese patients with dementia with a Mini-Mental State Examination score >10.