Measuring IADLs in Patients With, Without PD and MCI

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Mild cognitive impairment (MCI) affects older adults both with and without Parkinson disease (PD) and can impair the ability to participate in activities of daily living (IADL); a recent study sought to determine how both groups performed, compared with healthy adults, according to 4 measurements.

As a condition that exists beyond a state of normal cognition but is not full-fledged dementia, mild cognitive impairment (MCI) affects older adults both with and without Parkinson disease (PD). In a recent study, researchers were interested in evaluating if the severity or nature of functional difficulties in performing tasks linked to activities of daily living (IADL) were markedly different across both groups, compared with healthy adults.

Using multiple methods of assessment of examining IADL functioning—including direct observation, a performance-based measure, and self- and informant-report questionnaires—both groups with MCI performed worse than healthy adults. However, the types of difficulties exposed on the measurements differed, depending on whether the individual had PD-MCI or MCI alone.

Participants included 18 individuals with PD-MCI, 48 individuals with MCI, and 66 healthy older adults over the age of 50.

Participants came from a larger cross-sectional study evaluating IADLs using a naturalistic environment and smart technologies and completed standardized neuropsychological tasks and ADLs in a campus apartment.

Testing sessions were scheduled 1 week apart and lasted approximately 3 hours.

The assessment measures were a neuropsychological assessment; a functional assessment including a direct observation of the participant completing 6 activities in a campus apartment; a performance-based task evaluating the ability to manage daily medications using a pillbox; and the Instrumental Activities of Daily Living–Compensation Scale (IADL-C) questionnaire, both the self-report version and one completed by someone else.

The 6 activities included sweeping and dusting; washing hands; filling a medication pillbox; watering house plants; washing kitchen countertops; and preparing a cup of soup and pouring a glass of water.


in comparison with healthy adults, both the PD-MCI and MCI groups performed more poorly on all functional measures, including direct observation, self-report and informant report, and performance based, in line with the authors’ hypothesis as well as prior MCI research findings.

However, differences were seen in the direct observation measure in the types of issues illustrated by the assessment. Here, the PD-MCI group took longer and made more inefficient and irrelevant/off-task errors relative to those with MCI alone or in the healthy group. The MCI group made more omission and substitution errors relative to those in the healthy group.

The study had some limitations. The participants were not diverse (most were White and well educated) and there was a small sample size. Information about disease staging was not available. Lastly, participant performance on some of the tests, such as the activities in the campus apartment, may have been affected by being in an unfamiliar setting.


Schmitter-Edgecombe M, McAlister C, Greeley D. A comparison of functional abilities in individuals with mild cognitive impairment and Parkinson’s disease with mild cognitive impairment using multiple assessment methods. J Int Neuropsychol Soc. Published online September 6, 2021. doi:10.1017/S1355617721001077