Objectives: This study aimed to describe the baseline characteristics of informal carers of community-living Alzheimer's disease (AD) patients by AD severity group and to identify factors associated with two measures of caregiver burden.
Design and setting: GERAS is a prospective observational study in France, Germany, and the UK, designed to assess costs and resource use associated with AD, for patients and their caregivers, stratified by disease severity.
Participants: 1497 community-dwelling AD patients and their primary caregivers.
Measurements: Subjective caregiver burden assessed using the Zarit Burden Interview [ZBI] and time spent supervising patients (an objective measure of burden recorded using the Resource Utilization in Dementia instrument) during the month before the baseline visit were recorded. Separate multiple linear regression analyses using ZBI total score and caregiver supervision time as dependent variables were performed to identify patient and caregiver factors independently associated with caregiver burden.
Results: Increasing AD severity was associated with both subjective caregiver burden (ZBI total score) and overall caregiver time, which includes supervision time (both p<0.001, ANOVA). Better patient functioning (on instrumental activities of daily living) was independently associated with both a lower ZBI total score and less supervision time, whereas higher levels of caregiver distress due to patient behavior were associated with greater caregiver burden. Other factors independently associated with an increased ZBI total score included younger caregiver age, caregiver self-reported depression, caring for a male patient, and longer time since AD diagnosis. Caregivers living with the patient, being a male caregiver, patient living in a rural location, higher patient behavioral problem subdomain scores for apathy and psychosis, more patient emergency room visits, not receiving food delivery and receiving financial support for caregiving were all associated with greater caregiver supervision time.
Conclusion: Our results show that subjective caregiver burden and caregiver time are influenced by different factors, reinforcing the need to consider both aspects of caregiving when trying to minimize the burden of AD. However, interventions that minimize caregiver distress and improve patient functioning may impact on both subjective and objective burden.