Predictors of quality of life ratings for persons with dementia simultaneously reported by patients and their caregivers: The Cache County (Utah) Study

Background: Quality of life (QOL) is frequently assessed in persons with dementia (PWD) through self- and/or proxy-report. Determinants of QOL ratings are multidimensional and may differ between patients and caregiver proxies. This study compared self- and proxy-reported QOL ratings in a population-based study of PWD and their caregivers, and examined the extent to which discrepancies in reports were associated with characteristics of the PWD. Methods: The sample consisted of 246 patient/caregiver dyads from the initial visit of the Cache County Dementia Progression Study, with both members of the dyad rating PWD QOL. PWD age, gender, cognitive impairment (Mini-Mental State Examination), neuropsychiatric symptoms (Neuropsychiatric Inventory; NPI), dementia severity (Clinical Dementia Rating), medical comorbidities (General Medical Health Rating), and functional impairment (Dementia Severity Rating Scale) were examined as correlates of self- and proxy-reported QOL ratings and the differences between the QOL reports. Results: Self- and proxy-reported PWD QOL ratings were only modestly correlated. Medical comorbidity was associated with self-report whereas NPI was associated with proxy-report. Dementia severity was associated with discrepancies in self- and proxy-report, with worse patient cognition associated with poorer proxy-reported QOL ratings. Conclusions: PWD self- and proxy-reported QOL ratings are associated with different variables. Discrepancies between PWD and caregiver perceptions of PWD QOL should be recognized, particularly in cases of more severe dementia.