Contrasting results between caregiver's report and direct assessment of activities of daily living in patients affected by mild and very mild dementia: the contribution of the caregiver's personal characteristics.

OBJECTIVE: To determine the level of agreement between the primary caregiver's report on patient activities of daily living (ADLs) and ADLs assessed directly in a sample of patients affected by very mild and mild dementia and to assess whether this agreement is influenced by the caregiver's depressive symptoms and burden. PATIENTS AND METHODS: Data were obtained from the baseline sample of the Mild Dementia Longitudinal Study, consisting of 111 consecutive patients affected by dementia with very mild to mild functional impairment (grades .5 and 1 on the Clinical Dementia Rating Scale). As is usual for patients referred to our Alzheimer's Unit, anamnestic, cognitive, functional and behavioral information are collected from the primary caregiver. Along with sociodemographic characteristics, caregivers' depressive symptoms (Beck Depression Inventory Scale) and burden (Nowak and Guest's Caregiver Burden Inventory Scale) were also evaluated. Patients underwent a performance-based assessment of the activities of daily living (DAFS) and direct assessment of physical function with the Physical Performance Test (PPT). Caregiver's report and direct observation have been compared for the following ADLs: dressing, toileting, walking, telephone use, shopping, and money use. Discriminant analyses were conducted to examine the degree of agreement between caregiver-report functional status and performance-based measures and whether additional agreement is attributable to caregiver's burden and depressive symptoms.
RESULTS: The strength of the association between the caregiver's report and performance-based measures of ADLs is high for motor performance (walking), moderate to good for dressing, but only moderate for telephone, money use, and shopping. No association was found for toileting. The discrepancies between caregiver report and performance-based assessment were influenced substantially by the burden caused by demands and restrictions on a caregiver's time.
CONCLUSIONS: With the exception of motor performance (walking), the caregiver's report and the performance-based assessment of functional status measure different aspects of a patient's functional status. Contrasts between the caregiver's report and observed ADL performance in mildly and very mildly demented patients are influenced by the caregiver's burden.