Trajectories of irregular word reading ability as a proxy for premorbid intelligence in Alzheimer's disease, mild cognitive impairment, and healthy aging: A longitudinal study

Authors

Michael Weinborn
Romola Bucks
Hamid R. Sohrabi, Edith Cowan UniversityFollow
Stephanie Rainey-Smith, Edith Cowan UniversityFollow
Belinda M Brown
Samantha L Gardener
Aleksandra Gozt, Edith Cowan UniversityFollow
Daniel Christensen
Greg Savage
Simon Laws, Edith Cowan UniversityFollow
Kevin Taddei, Edith Cowan UniversityFollow
Paul Maruff
Joanne S Robertson
Kathryn A Ellis
David Ames
Colin L Masters
Christopher C Rowe
Ralph Martins, Edith Cowan UniversityFollow

Document Type

Journal Article

Publication Title

Psychological Assessment

ISSN

1939-134X

Volume

30

Issue

10

First Page

1308

Last Page

1316

PubMed ID

29781669

Publisher

American Psychological Association Inc.

School

School of Medical and Health Sciences

RAS ID

27300

Comments

Weinborn, M., Bucks, R. S., Sohrabi, H. R., Rainey-Smith, S. R., Brown, B. M., Gardener, S. L., ... & Taddei, K. (2018). Trajectories of irregular word reading ability as a proxy for premorbid intelligence in Alzheimer’s disease, mild cognitive impairment, and healthy aging: A longitudinal study. Psychological assessment, 30(10), 1308. Available here

Abstract

The ability to read irregularly spelled words is commonly used to estimate premorbid intelligence, as this ability has been thought to be resistant to early effects of neurodegenerative disorders. However, studies evaluating decline of this skill in Alzheimer's disease (AD) have produced conflicting results. Irregular word reading was assessed three times over 36 months in a large (N = 995) sample, including healthy control, AD, and Mild Cognitive Impairment (MCI) groups. At baseline, MCI and AD groups read correctly an average of 3.01 and 7.39 fewer words, respectively, than healthy controls. The MCI group's performance remained stable during the study, but the AD group declined. Importantly, the observed decline was likely an underestimate, as significant numbers of the AD participants (42.6%) could not complete the task at follow-up. Use of alternate (e.g., demographics-based) methods is advised to augment or replace word pronunciation in estimating premorbid intelligence in individuals with even mild AD. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

DOI

10.1037/pas0000565

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