A preliminary investigation conducted by a collective of scientists from Lund University demonstrates that their concise, self-administered digital cognitive assessment instrument, designated BioCog, possesses the capability to identify cognitive impairment and, when integrated with a blood analysis, accurately ascertain clinical Alzheimer’s disease within the primary healthcare setting.
Within the domain of primary care, the BioCog assessment achieved an 85% accuracy rate when a singular threshold was employed to classify cognitive impairment, a performance notably superior to that of primary care physicians’ evaluations (which yielded a 73% accuracy). Image attribution: Miroslaw Miras.
Alzheimer’s disease stands as the predominant etiology of dementia, characterized by the accumulation of amyloid-beta plaques, the aggregation of tau proteins, and a progressive decline in neural function.
The clinical manifestation of Alzheimer’s disease typically commences with a phase of subjective cognitive decline, wherein individuals report experiencing memory deficits and/or other intellectual challenges, yet exhibit normal performance during cognitive evaluations.
This initial stage is succeeded by mild cognitive impairment, distinguished by objectively observable cognitive symptoms, followed ultimately by dementia, which is recognized by pronounced functional limitations affecting daily living activities.
The process of diagnosing Alzheimer’s disease presents considerable challenges, particularly during the incipient stages of the condition and within the context of general medical practice.
There is a substantial incidence of both underdiagnosis and incorrect diagnosis, with an estimated 20-30% of individuals receiving an inaccurate diagnosis in specialized care settings and approximately 40% in primary care where the Alzheimer’s diagnosis is not substantiated by specific biomarkers.
“The BioCog digital assessment, which patients undertake independently with minimal intervention from medical personnel, enhances the capacity of primary care physicians to determine which individuals warrant further scrutiny through blood tests for Alzheimer’s pathology at an early juncture in the investigative sequence,” remarked Professor Oskar Hansson of Lund University.
“Primary healthcare facilities lack the requisite resources, allotted time, or specialized expertise to thoroughly investigate potential cases of Alzheimer’s disease in a manner comparable to specialized memory assessment centers.”
“It is precisely in this area that a digital cognitive assessment can exert the most significant positive influence.”
In contrast to conventional paper-and-pencil assessments, which are commonly utilized to gauge cognitive impairment, digital evaluations offer a more granular and comprehensive perspective.
Additional facets and novel variables, previously difficult to quantify with ease, are now incorporated into the assessment process.
“The overwhelming majority of individuals experiencing memory disturbances will initially seek medical attention at their local health center,” stated Pontus Tideman, a doctoral candidate at Lund University and a psychologist affiliated with the Memory Clinic at Skåne University Hospital.
“Our novel digital assessment provides an initial objective representation – at an earlier stage and with enhanced precision – of which patients exhibit cognitive impairment suggestive of Alzheimer’s disease.”
“This insight identifies individuals who should proceed with blood testing to measure phosphorylated tau levels, a test that can accurately detect Alzheimer’s pathology within the brain.”
Currently, these specialized blood analyses are exclusively accessible within dedicated hospital clinics or memory assessment centers.
While the long-term objective includes their availability in primary care settings, the intention is not to administer blood tests to all patients presenting with cognitive concerns.
The research team posits that this digital instrument could offer substantial advantages, given the current considerable difficulty in diagnosing Alzheimer’s disease during a brief patient consultation lasting 15 to 20 minutes.
This is precisely where digital tools, capable of objectively quantifying cognitive abilities, can effect a substantial difference.
“The distinctive characteristic of our BioCog test lies in its evaluation within a primary care demographic, meaning patients seeking medical intervention at a health center due to cognitive complaints, such as memory difficulties,” explained Linda Karlsson, a doctoral candidate at Lund University.
“The amalgamation of results derived from the digital assessment and the blood test serves to augment the diagnostic accuracy for Alzheimer’s disease.”
“The fundamental objective of this assessment is to simplify procedures for general practitioners.”
The BioCog test is detailed in a publication featured in the esteemed journal Nature Medicine.
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P. Tideman et al. Primary care detection of Alzheimer’s disease using a self-administered digital cognitive test and blood biomarkers. Nat Med, published online September 15, 2025; doi: 10.1038/s41591-025-03965-4
