Around 55 million people worldwide live with dementia, and an estimated 60% to 80% of those individuals suffer from Alzheimer’s Disease (AD), according to the World Health Organization (WHO). That number is expected to increase to around 139 million within 25 years.

Projections from the National Center for Health Workforce Analysis indicate that by 2025, the demand for neurologists will surpass the available supply across all regions of the United States. Access to specialist services is already restricted or nonexistent in some low- and middle-income countries. Consequently, many individuals with cognitive impairments do not and will not receive proper evaluations, and it is anticipated that access to dementia specialists will become increasingly constrained in the future.

Already, data suggests that 31- 74% of patients with symptomatic AD are not identified, which can lead to delays in care, administration of inappropriate therapies and incorrect prognostic guidance.

Last week, a peer-reviewed article was published in Nature Reviews Neurology by the Global CEO Initiative on Alzheimer’s Disease BBM (blood biomarker) Workgroup, highlighting why “blood tests for Alzheimer’s disease promise to provide an earlier and more accurate diagnosis for many patients with cognitive impairment.”

“Some currently available blood tests are extremely accurate while others are little better than flipping a coin,” explained Workgroup lead Suzanne Schindler. “We worked with many stakeholders to develop minimum standards for the accuracy of these blood tests because we know that a timely and accurate diagnosis of Alzheimer’s disease has a major impact on a patient’s life.”

Since 2021, new treatments for AD that modify the disease’s progression have started to be used in clinical practice. The FDA has approved two amyloid-β antibody treatments, aducanumab and lecanemab, and is currently reviewing a third, donanemab. These therapies are designed for early stages of AD, including mild cognitive impairment or mild dementia, and require confirmation of amyloid plaques in the brain before starting treatment.

Anti-amyloid treatments help by targeting and removing beta-amyloid, a protein that forms plaques in the brain. Each therapy works uniquely, targeting different stages of plaque formation.

The team wrote in its paper that because Amyloid PET and CSF tests have limitations and aren’t easy to scale up, BBM tests are likely to become the primary method for diagnosing Alzheimer’s. They said that BBM tests are more convenient and accessible and can quickly increase in number to meet the rising demand. They can also be used in primary care (like your regular doctor’s office) and secondary care (specialist clinics), making them a practical option for more widespread testing and treatment.

“The backdrop that’s important to understand here is that the current state of the Alzheimer’s disease diagnostic pathway has at least two primary bottlenecks, including long wait times to see brain health specialists, made worse by overwhelmed primary care providers who lack the practical tools, operational support and standardized assessment process to triage patients effectively,” Tim MacLeod, director of the Healthcare System Preparedness Program of the Davos Alzheimer’s Collaborative (DAC), told Health Policy Watch.

“Traditional diagnostic inputs to inform an Alzheimer’s diagnosis are typically expensive and not readily accessible. Current methods may include lumbar puncture to collect cerebral spinal fluid and imaging such as positron emission tomography or magnetic resonance imaging.

“Blood biomarkers are a promising tool that could help make the diagnostic pathway more time and resource-efficient,” he continued, commenting in general and not on the new Nature report specifically.

The BBM Workgroup recommended that a BBM test have a sensitivity of ≥90 percent, with a specificity of ≥85 percent in primary care and ≥75–85% in secondary care, depending on the availability of follow-up testing.

The CEOi BBM Workgroup, which includes 90 stakeholders from healthcare, academia, non-profit, government, venture capital, industry, and patient advocacy, said its performance standards can be used for any test and does not endorse any specific BBM test. Its standards reflect an expert consensus, marking the first time stakeholders have united to establish a common framework.

The group said that “by adhering to these performance standards, high-quality BBM tests have the potential to revolutionize Alzheimer’s diagnosis, enabling more patients to receive the timely and accurate assessment of whether they may wish to consider using newly approved disease-modifying treatments.”

“A delayed diagnosis to a later stage of the disease will effectively deny access to current and promising disease-modifying treatments,” commented George Vradenburg, founding chairman of the DAC. “Diagnosis delayed will mean treatment denied.”

‘Significant Challenges’

However, MacLeod said, “Unsurprisingly, as we watch health systems plan, we’re observing that while specialty sites of care may have a diagnostic pathway, there are significant challenges in making those pathways scalable through the addition of primary care.”

He said, for example, that figuring out how primary care teams can identify patients who need a blood test is a widespread challenge. This process demands significant operational changes and better cooperation across different practice areas. Additionally, there are practical issues like limited access to specialists and long referral wait times. In some cases, providers within their system are skeptical about the availability and effectiveness of treatment and support options, further complicating the efforts of primary care providers to address cognitive complaints.

To address these challenges, the DAC has launched a new initiative across health systems in five countries. This initiative uses BBMs and confirmatory diagnostic testing to improve the timely and accurate diagnosis of Alzheimer’s disease and related dementias (ADRD). Managed by the DAC Healthcare System Preparedness (DAC-SP) team, the Accurate Diagnosis project is the first global research program to explore the integration of blood biomarkers in the ADRD diagnostic process.

“This program – implemented in both primary and specialty care centers – will help us understand the barriers to implementing blood biomarkers and the ways in which blood may help drive efficiencies in the diagnostic process,” MacLeod told Health Policy Watch.

Healthcare systems in Germany, Japan, the Netherlands, the United Kingdom and the United States will implement, evaluate, and share insights on using BBMs and confirmatory Alzheimer’s pathology testing. This project aims to integrate these tests, typically used in research, into routine clinical practice, speeding up the adoption of validated tools for timely patient care.

Sites were chosen based on their scientific and clinical expertise and their ability to reach diverse patient populations in terms of age, race, ethnicity, education, socioeconomic status, and geographic location, DAC said. The initial sites include:

• University of Kansas Alzheimer’s Disease Research Center
• Icahn School of Medicine at Mount Sinai
• Wake Forest University School of Medicine
• Alzheimer Center Amsterdam at Amsterdam UMC
• Imperial College London and Imperial College Healthcare NHS Trust
• Ludwig-Maximilians University (LMU) Hospital Munich – Alzheimer’s Therapy and Research Center
• Tokyo Metropolitan Institute for Geriatrics and Gerontology

“The project sites are just beginning … to get patients enrolled this summer and hope to have results to share in 2026,” MacLeod shared. “One of the primary aims of this program is to make implementation easier for other health systems that want to implement this type of program.

To that end, we will co-design a blueprint with site leaders informed by our research learning that will help translate lessons learned and effective implementation strategies into pragmatic, actionable tools that can be harnessed by health system leaders.

“Additionally, by using implementation science methods, we are uniquely positioned to learn as we go,” MacLeod continued. “We are already seeing learnings emerge in the start-up phase that we expect will be of great benefit to future health systems wanting to use blood biomarkers in their practice. And by bringing the site leaders together for a monthly community of practice, they have the unique benefit of being able to share their learnings with one another and get creative as they navigate common challenges in their project planning.”

MacLeod stressed that “the stakes are really important here” as an accurate diagnosis is a necessary first step toward receiving interventions such as lifestyle modifications, pharmacological treatments, education, support, practical care and legal planning.

“As new treatments become available, pinpointing the patients who can benefit most from them will be essential since current treatments and interventions are effective when administered at earlier stages of the disease,” MacLeod said. “This is the first time [an implementation study of BBMs] has been done. Our goal is to speed up research and get directly to the patient faster.

“This is a very optimistic time for the field.”

Image Credits: Photo by Steven HWG on Unsplash, John Heilprin.