Date of Award

4-2018

Degree Name

Doctor of Philosophy

Department

Interdisciplinary Health Sciences

First Advisor

Dr. Linda Shuster

Second Advisor

Dr. Carla Chase

Third Advisor

Dr. Nichola Wolf Nelson

Keywords

Mild cognitive impairment, aging, assessment

Abstract

This dissertation is a series of three studies aimed at determining the best assessment practices for mild cognitive impairment (MCI) that can employed by speech-language pathologists (SLPs). The first study was non-experimental and descriptive examining whether three commonly used assessment instruments yielded similar categorical results. The data were analyzed to determine whether the Eight-Item Interview to Differentiate Aging and Dementia (AD8), the Mini-Mental State Examination (MMSE), and the Cognitive-Linguistic Quick Test (CLQT) identified the same participants from a neurotypical sample as having cognitive deficits. Very little agreement was found amongst the three tools.

Study two was modified to include two participant groups – one with self-reported MCI or mild dementia, and one neurotypical group. The addition of the disordered group allowed statistical analyses to include measures of sensitivity and specificity using the diagnosed condition as the “gold standard” for analyses. In addition, the MMSE was replaced with the Montreal Cognitive Assessment (MoCA) because it had been show to be more sensitive to mild impairments as compared to the MMSE. The AD8 was also given to close family caregivers of each participant to compare self-report to the report from a different informant. Finally, the Large Allen Cognitive Levels Screen, 5th edition (LACLS-5) was added to this study to collect data on participants’ abilities to complete activities of daily living (ADLs). The MoCA and the LACLS-5 identified the most participants across both groups as having cognitive deficits, however the AD8 as completed by another informant was found to have the greatest sensitivity and specificity.

Finally, the third study was qualitative with the purpose of learning more about the experience of being tested, as well as what the experience of being diagnosed with MCI or AD/dementia may be like. Overall the test that was the most preferred was the CLQT, which identified the least number of participants in study two. In contrast, the LACLS-5 was the least preferred tool but identified the greatest number of individuals as having cognitive deficits. Participants in the neurotypical group were further asked questions about whether they would want to be tested if they were referred for a cognitive examination, and whether they would want to learn of a cognitive diagnosis. All participants stated they would want to be informed, however they also voluntarily participated in this study, so they likely had an innate interest in the topic. Reasons for wanting to be informed related to the need for financial planning for the future and advanced care planning for their healthcare wishes.

In conclusion, this series of three separate studies cannot guide practicing SLPs toward or away from any single assessment instrument, either quantitatively or qualitatively. Rather, it may be more clinically appropriate to determine if a combination of tools may provide the most comprehensive look at cognitive function that falls in line with the diagnostic criteria created by the National Institute on Aging and the Alzheimer’s Association (NIA/AA taskforce).

Access Setting

Dissertation-Open Access

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