Discriminative power of the advanced activities of daily living (a-ADL) tool in the diagnosis of mild cognitive impairment in an older population

Background: Mild cognitive impairment (MCI) is characterized by subjective and objective memory impairments in the absence of manifest functional decline. Mild changes in activities of daily living (ADL) can be present and probably predict conversion to dementia. A new advanced (a)-ADL tool was developed, evaluating high-level activities and, taking each participant as their own reference, distinguishing a global Disability Index (a-ADL-DI), a Cognitive Disability Index (a-ADL-CDI), and a Physical Disability Index (a-ADL-PDI), based on the number of activities performed and the severity and causes of the functional problem. This study evaluates the discriminative validity of the a-ADL in MCI. Method: Based upon clinical evaluation and a set of global, cognitive, mood, and functional assessments, 150 community-dwelling participants (average age 80.3 years (SD 5; 66-91)) were included and diagnosed as (1) cognitively healthy participants (n = 50); (2) patients with a-MCI (n = 48), or (3) mild to moderate AD (n = 52). The a-ADL tool was not a part of the clinical evaluation. Results: The a-ADL-DI and the a-ADL-CDI showed a sensitivity and specificity ranging from 70% to 94.2%, Positive Predictive Value ranging from 70% till 93.8%, and Negative Predictive Value from 64.4% and 93.8%, an area under the curve (AUC) ranging from 0.791 to 0.960. Functional decline related to physical deficits, as assessed by the a-ADL-PDI, did not discriminate between the different groups. Conclusion: The a-ADL tool has a good ability to distinguish normal and pathological cognitive aging. Its discriminative power for underlying causes of limitations may be an advantage.