Patient versus informant perspectives of quality of life in mild cognitive impairment and Alzheimer's disease

Background Prior studies on Quality of Life (QOL) in Alzheimer's disease (AD) have rarely included control participants, or participants with very mild levels of cognitive impairment. Furthermore, there is little data to indicate whether or not mildly impaired patients can provide self-report QOL data or if informant reports are needed. Objectives This study compared QOL ratings from informants and patients with mild AD (n = 26), Mild Cognitive Impairment (MCI, n = 30), and elderly controls (n = 23). Methods Participants (aged 60-91 years) were recruited from an outpatient memory disorder clinic. Elderly controls were recruited from the community. Measures about patients were the Dementia Quality of Life scale, the Neuropsychiatric Inventory-Questionnaire, Instrumental of Activities of Daily Living, and Mini-mental State Exam. Informant depression was assessed with the Geriatric Depression Scale. Results Results indicated that overall patient-informant agreement for MCI (M = 0.24), AD (M = 0.48), and controls (M = 0.49) did not differ significantly. Self-reported QOL did not differ significantly across the 3 groups. For caregiver-reports, QOL in MCI again did not differ from controls but was significantly greater than QOL in AD for 2 of 6 scales, and QOL in controls was greater than AD for 4 of 6 scales. Regression analyses indicated that neuropsychiatric symptoms were the most consistent predictors of QOL. Conclusions In summary, informant- and self-perceptions of QOL differed substantially. Results suggest that future investigators should carefully consider gathering QOL information from both informants and patients because they provide unique information regarding patient QOL and, to date, neither source of information has been established to be superior. Copyright (C) 2004 John Wiley Sons, Ltd.