A simple blood test could transform how Alzheimer’s disease is diagnosed across Asia-Pacific — but only if health systems are prepared to deploy it at scale.
There is a moment, somewhere in the middle of the journey to an Alzheimer’s disease diagnosis, when the waiting becomes the hardest part. Not the appointments – though those are exhausting. Not the tests – though those are often invasive, expensive, and inconclusive. It’s the uncertainty between them. The months, sometimes years, of not knowing whether the memory lapses are the beginning of something serious, or simply an ageing mind.
For most people living with early Alzheimer’s disease across the Asia-Pacific region, that uncertainty lasts far longer than it should. Between the first symptom and a confirmed diagnosis, the average wait is one to three years.¹ In many parts of the region, it’s longer. And with a disease where the biological window for effective intervention is finite – and where the treatments most likely to modify the disease course are only effective when they are given early – that delay carries real clinical consequences.
Part 1 of this series established the scale of the Alzheimer’s challenge across the Asia-Pacific region: 26 million people with diagnosed dementia, 130 million more with undetected preclinical disease, and health systems calibrated almost entirely to respond to the visible tip of the iceberg.
This article addresses the question that follows: how do we close the gap between where patients are and where they need to be – and what will it take to build a diagnostic system capable of finding Alzheimer’s disease before it finds them?
The diagnostic bottleneck
To understand the scale of the problem, it helps to trace the diagnostic pathway as it currently exists across most of the Asia-Pacific region.
A patient – typically presenting in their sixties or seventies, often prompted by a family member rather than their own concern – visits a primary care physician with cognitive complaints. The physician, who in many systems has limited training in cognitive assessment and no access to specialist decision-support tools, refers them for further evaluation. That referral joins a queue.
In many economies, the wait for a specialist appointment stretches for months. In rural and underserved communities, the nearest specialist may be hours away, requiring significant travel, time off work, and out-of-pocket expense.
When the specialist appointment eventually arrives, the pathway to biological confirmation itself requires multiple steps. Clinical evaluation, neuropsychological assessment, and structural MRI or CT imaging to exclude other causes of cognitive decline must typically be completed before cerebrospinal fluid (CSF) analysis or positron emission tomography (PET) scanning is considered.
Only if Alzheimer’s disease remains the likely diagnosis after this process will a specialist order confirmatory biomarker testing. CSF testing is invasive; PET scanning is expensive, technically demanding, and heavily concentrated in tertiary centres. In many economies across the region, reimbursement for either is limited or non-existent.²
The result is a bottleneck that compounds at every stage – and a patient who remains in diagnostic limbo throughout, unable to access the emerging class of disease-modifying therapies that require biomarker-confirmed early-stage Alzheimer’s disease as an eligibility criterion.
As a result, up to 90% of dementia cases in some Asia-Pacific settings go undetected.¹ Of those that are detected, the majority are identified at a moderate or advanced stage – when the most promising new treatments are least likely to be effective.
Why the delay matters more than ever
The development of disease-modifying therapies has added a new and urgent dimension to the diagnostic problem. The emerging class of anti-amyloid therapies are early-stage interventions by design. Their clinical benefit is demonstrated in patients with mild cognitive impairment or mild dementia due to Alzheimer’s disease, confirmed by biomarker evidence of amyloid pathology.
In patients who have already progressed beyond this stage, they are unlikely to offer meaningful benefit. In patients who have not been biomarker-confirmed, they cannot be safely or appropriately administered at all.
The value of disease-modifying therapies is inseparable from the quality of the diagnostic pathway that identifies eligible patients. A health system that takes one to three years to reach a diagnosis – and reaches it, in most cases, without biomarker confirmation – will systematically miss the treatment window, even after those treatments are approved and available.¹
Until the diagnostic delay is addressed, the promise of a new era of Alzheimer’s treatment will remain out of reach for the vast majority of patients across the Asia-Pacific region.
The solution is in the blood
The good news is that a scalable solution already exists. It doesn’t require building new hospitals, training thousands of new specialists, or waiting for regulatory approvals that have not yet arrived.
Blood-based biomarkers (BBBMs) represent a fundamental change in Alzheimer’s diagnostics. Proteins associated with Alzheimer’s pathology – most notably phosphorylated tau variants such as pTau181 and pTau217 – can be detected in a standard blood draw with a level of accuracy that is now clinically meaningful.³
The key clinical function that BBBMs perform is triage. A blood test with high negative predictive value – such as pTau, which can reliably identify patients who do not have Alzheimer’s pathology – can be deployed at the primary care level to stratify patients before any specialist referral, PET scan or lumbar puncture.⁴
Patients who test negative can be redirected to appropriate alternative care without consuming specialist capacity. Patients who test positive can be fast-tracked through the confirmatory pathway – CSF analysis or PET – with confidence that the referral is clinically justified.5 6
The shift from PET-first to BBBM-triage-first removes the dependency on specialist-first pathways for initial triage, reduces avoidable referrals to tertiary centres, and dramatically shortens the time from first symptom to confirmed diagnosis.
The fiscal case is as compelling as the clinical one. In China, CSF-based biomarker testing has been shown to reduce diagnostic pathway costs by 33–37% compared with Aβ-PET, while maintaining equivalent diagnostic accuracy – reducing per-patient diagnostic spending by approximately ¥1,900 to ¥2,100.7
For health systems facing both a volume challenge and a budget constraint, that efficiency gain is the difference between a diagnostic pathway that is financially sustainable at scale and one that is not.
It also creates the population-level screening infrastructure that is currently absent across almost every economy in the region: a way to find patients earlier, when intervention is still meaningful.
Two speeds, one direction
The clinical pathways, reimbursement frameworks, and workforce capacity needed to deploy this technology at scale remain the central challenge. Across the region, health systems broadly fall into two archetypes, each with distinct priorities for reform.
Higher-income economies – Japan, South Korea, Australia, Singapore, Taiwan, Hong Kong, and New Zealand – generally have the imaging infrastructure that advanced Alzheimer’s diagnostics require. The challenge centres on pathway design: integrating BBBMs as a systematic triage layer into existing workflows and standardising referral criteria.
South Korea illustrates this clearly. The country has among the highest density of PET and MRI scanners in the region, yet diagnostic delays persist because the pathway connecting a patient with cognitive complaints to a confirmed Alzheimer’s diagnosis is still fragmented. Without structured BBBM triage at the primary care level, PET capacity is consumed by patients who could have been ruled out earlier and more cheaply, creating bottlenecks for those who genuinely need confirmatory imaging.¹
Mature economies should initiate health technology assessments and pilots within twelve months – a timeline that reflects both the urgency of the diagnostic gap and the feasibility of acting quickly within existing infrastructure.¹
For upper-middle-income economies – China and Thailand – the challenge is more fundamental. The volume of patients is already enormous and growing fast. The PET-first model is not workable at that scale: not enough scanners, not enough trained operators, not enough reimbursement.
For these systems, BBBMs offer a means of building scalable, primary-care-based diagnostic infrastructure that bypasses the bottlenecks of the specialist-and-scanner model entirely. The cost-efficiency data reinforces the case: where CSF biomarker testing already reduces diagnostic costs by a third compared with PET, the financial logic of a BBBM-first pathway is difficult to argue against.7
The direction of travel is the same across both archetypes. The speed and the starting point differ. What matters is that both begin to move – and that policy frameworks and reimbursement mechanisms are developed in parallel with clinical infrastructure.
Funding gaps could derail progress
Even if every health system across the Asia-Pacific region were to adopt blood-based biomarker triage tomorrow, a structural problem would prevent those diagnostics from translating into patient benefit: the way Alzheimer’s disease treatment is currently funded.
In most economies, reimbursement decisions for new treatments are made in isolation from the diagnostic and monitoring costs that surround them. A health system may approve reimbursement for a disease-modifying therapy without simultaneously establishing reimbursement for the biomarker confirmation required to determine eligibility, the monitoring protocols required to ensure safe administration, or the follow-up testing required to track treatment response.
Applying legacy reimbursement models to a new class of precision therapies carries significant fiscal risk. Without biomarker-linked eligibility criteria embedded in reimbursement decisions, disease-modifying therapies risk being administered to patients who are ineligible – too advanced to benefit, or without confirmed amyloid pathology – at substantial cost and with negligible clinical return.²
The solution is a bundled payment model: a reimbursement framework that treats diagnosis, treatment, and monitoring as a single, integrated package. Under this model, any newly approved disease-modifying therapy would be financed as part of a comprehensive pathway – with biomarker confirmation funded, monitoring protocols funded, and eligibility criteria clearly defined.
This protects the fiscal efficiency of therapeutic investment by ensuring treatments reach the right patients at the right stage, and builds the accountability mechanisms that payers and regulators will need to evaluate real-world performance over time.²
Alongside bundled payments, health technology assessment (HTA) fast-tracks for both disease-modifying therapies and their companion diagnostics are essential. Reimbursement frameworks that lag years behind scientific progress actively delay patient access, widen equity gaps, and undermine the return on the research investment that produced the treatments in the first place.¹
From diagnostic gap to diagnostic readiness
The 1–3 year diagnostic delay that currently characterises Alzheimer’s care across the Asia-Pacific region is a design challenge – reflecting the absence of systematic early detection infrastructure, the underinvestment in biomarker-based diagnostics, and the persistence of reimbursement models built for a different era of Alzheimer’s medicine.¹
The tools to close that gap exist. Blood-based biomarkers can move the point of triage from the specialist clinic to the primary care appointment. Bundled payment models can align the financial incentives of health systems with the clinical logic of early intervention.
Task-shifting protocols can extend diagnostic reach without requiring a specialist workforce that does not yet exist at the scale the region needs. Hub-and-spoke diagnostic networks can ensure that the confirmatory layer of the pathway is accessible to patients who do not live near a tertiary centre.¹
What’s missing is the policy architecture to deploy what already exists – at scale, with equity, and with the urgency that the epidemiological trajectory of Alzheimer’s disease in the Asia-Pacific region demands. Without funded diagnostics, the new era of Alzheimer’s treatment will not be a revolution in care across the Asia-Pacific region.
It will be a revolution available only to those wealthy enough, or urban enough, or fortunate enough to access it privately. That outcome would deepen the inequity that already defines too much of the region’s approach to Alzheimer’s disease.
We have the technology to find the disease. The question now is whether health systems across the Asia-Pacific region will lead the way.
Read Part 3: From Policy to Patient: Building a System Ready for the New Era of Alzheimer’s
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