RELIABILITY AND VALIDITY OF THE QUALITY OF LIFE-ALZHEIMER’S DISEASE QUESTIONNAIRE IN MALAY LANGUAGE FOR MALAYSIAN OLDER ADULT WITH DEMENTIA
The Quality of Life-Alzheimer’s Disease (QOL-AD) questionnaire is a reliable, valid and popular outcome measure in dementia related studies. However, to date there is no published report on adopted version of QOL-AD in Malay language. Thus this preliminary study aimed to evaluate the reliability and validity of the QOL-AD in Malay language for patients with dementia and to examine the level of agreement between patient-caregiver as a proxy reports on patient’s quality of life. A total of 65 patients with mild to moderate dementia and their caregivers were recruited from the psycho-geriatric clinic, Universiti Kebangsaan Malaysia Medical Centre using a cross sectional study design. The QOL-AD was translated into Malay language using the standard guidelines for cross-cultural adaptation of measure. The patient-caregiver dyads completed the QOL-AD in Malay language separately. Test-retest and internal consistency was evaluated for reliability and construct validity was tested with principal component factor analysis. The reliability of QOL-AD in Malay language was good with Cronbach alpha coefficients of 0.82 and 0.79 and intraclass correlation coefficients of 0.77 and 0.89 for patients and caregivers report respectively. Meanwhile a positive moderate agreement was achieved between patient and caregiver rating (r=0.60, p<0.01). The principal component factor analysis extracted 4 factors for both patient and caregiver reports which explained 66.02% (patients’ report) and 64.24% (caregivers’ report) of the total variance of the scale. As a conclusion, the QOL-AD in Malay language is a reliable and valid tool to measure the quality of life of people with mild to moderate dementia.
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