Reliability and validity of the quality of life-Alzheimer disease Chinese version

To evaluate the psychometric properties of the quality of life-Alzheimer disease (QOL-AD) Chinese version in patients with dementia in mainland, China and to compare patient and caregiver reports of patient QOL.

The QOL-AD Chinese version was established following standard guidelines for cross-cultural adaptation of measures. The reliability was assessed by internal consistency and test-retest reliability. The validity included construct and convergent validity. A paired Student t test was performed to determine differences between patient reports and caregiver reports.

The reliability for both patient and caregiver reports on the QOL-AD was good (Cronbach α values of 0.66 and 0.87; intraclass correlation coefficients of 0.84 and 0.90 for patient and caregiver reports, respectively). The validity of patient and caregiver reports was supported by correlation with domain measures. All of the multitrait-multimethod correlations demonstrated a high relationship between patient reports and caregiver reports, ranging from 0.26 to 0.55. The caregivers rated patient QOL significantly higher than did the patients.

The findings support the use of the Chinese version of the QOL-AD as a generic instrument to measure QOL of AD in mainland China. Further research is needed to clarify the relationship between patient and caregiver reports of patient QOL.