Author Identifier (ORCID)
Abstract
Introduction: Recent advances allow blood tests to detect key proteins linked to Alzheimer's disease (AD). Methods: In this before-and-after study across three Australian memory and cognition clinics, we evaluated the impact on clinicians' diagnostic confidence and management following disclosure of routine patients' AD probability, using predefined plasma phosphorylated tau 181 (pTau181) thresholds set at 90% sensitivity and 90% specificity for amyloid-beta (Aβ) positron emission tomography (PET) positivity. Results: One hundred thirteen participants (mean age: 71.2 ± 8.4; mean Mini-Mental State Examination score: 27.7 ± 2.5) with dementia (n = 17, 15.0%), mild cognitive impairment (n = 48, 42.5%), and subjective cognitive decline (n = 48, 42.5%) were enrolled. Blood test results were “probably negative,” n = 81, 71.7%; “indeterminate”, n = 24, 21.2%; and “probably positive,” n = 8, 7.1%. In 12 cases (10.6%), pTau181 changed clinician diagnosis and increased mean diagnostic confidence from low-to-moderate (61%) to moderate-to-high (80%). Aβ PET in 40 participants showed plasma pTau181 improved diagnostic accuracy by 5%. Discussion: This study demonstrates the benefits of plasma pTau181 in real-world clinical practice particularly when diagnostic confidence is only low-to-moderate.
Keywords
Alzheimer's disease, blood-based biomarkers, dementia, diagnostic change, management change
Document Type
Journal Article
Date of Publication
4-1-2026
Article Number
e70386
Volume
18
Issue
2
Publication Title
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring
Publisher
Wiley
School
School of Medical and Health Sciences
Funding Information
This study was supported by NHMRC Boosting Dementia Grant ‘The Australian Dementia Network (ADNeT): Bringing together Australia’s dementia stakeholders' (Grant number: APP1152623).
Funding received from the National Health and Medical Research Council (NHMRC)
APP1152623
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Michaelian, J. C., Feizpour, A., Vickers, J. C., Alty, J. E., Collins, J. M., Doré, V., Ireland, C., King, A. E., Martins, R. N., Woodward, M., Naismith, S. L., & Rowe, C. C. (2026). Impact of plasma pTau181 levels on clinician diagnostic confidence and management in memory and cognition clinics: A multi‐site before‐and‐after study. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 18(2), Article e70386. https://doi.org/10.1002/dad2.70386