REPORT-BASED VERSUS OBSERVATION-BASED ASSESSMENT OF DAILY LIVING TO SUPPORT DIAGNOSIS OF MILD COGNITIVE IMPAIRMENT IN A GERIATRIC POPULATION: WHAT TO CHOOSE?

Background: Amnestic-Mild Cognitive Impairment (a-MCI) is seen as a transitional state between normal ageing and Alzheimer Dementia (AD). Identifying a-MCI is crucial for early management of AD. Functional decline, measured... [ view full abstract ]

Background:
Amnestic-Mild Cognitive Impairment (a-MCI) is seen as a transitional state between normal ageing and Alzheimer Dementia (AD). Identifying a-MCI is crucial for early management of AD. Functional decline, measured with the report-based advanced-(a-)-Activities-of-Daily-Living-Cognitive-Disability-Index (a-ADL-CDI) (De Vriendt ea) and the observation-based Natural-Action-Test (NAT) (Giovanetti ea) showed good discriminative validity between normal ageing, a-MCI and AD in separate studies. This study aimed to establish the discriminative and convergent validity of both tools in one sample.

Method:
Thirty community dwelling 65+ were, based on cognitive, functional and mood assessment, diagnosed as cognitively healthy (CH) (n=10), a-MCI (n=10) or mild AD (n=10). The a-ADL-CDI and NAT were administered separately from diagnostic procedure.

Results:
Both a-ADL-CDI and NAT showed significant differences between 3 groups with CH < a-MCI < AD (all p<0.00). They were significantly (all p<0.01) correlated with each other (r 0.806) and with the cognitive measures (r between 0.754 and 0.832). The accuracy of the NAT and the a-ADL-CDI to distinguish CH from a-MCI, a-MCI from AD and CH from AD, was respectively an AUC of 0.855, 0.900 and 1.000 versus 0.780, 0.850 and 1.000).

Conclusion:
The NAT and the a-ADL-CDI have a strong convergent validity and more or less the same discriminative validity. A report-based instrument has, however, the advantage to be less time and money consuming, more feasible and more acceptable for both patient as professional compared with a performance-based tool.

Application to Practice:
Depending on the possibilities in the own practice, one has to choose the most appropriate tool.