Released today on World Alzheimer’s Day, new research has found earlier, more certain Alzheimer’s disease diagnosis could generate $18.21 in wider social value for every $1 invested in a more accessible diagnostic test.

The forecast Social Return on Investment (SROI) analysis model shows an investment of approximately NZ$5.65 million would generate around NZ$102.87 million in social and economic value, with benefits extending across an estimated 9,055 people with likely Alzheimer’s disease, 5,146 partners and 19,015 children.

The findings are published in A Clearer Path Forward: Social Return on Investment of a more accessible diagnostic test to increase certainty of Alzheimer’s disease in Aotearoa New Zealand, prepared independently by health economics consultancy HTANALYSTS and commissioned by Roche Diagnostics. The report will today be formally presented to Todd Stephenson, ACT Party politician and health spokesperson as part of its New Zealand launch.

SROI analysis considers the broader social and economic value created by an investment, including outcomes such as independence, wellbeing, relationships and the ability to plan for the future. It translates the lived experiences of patients, carers, and whānau into measurable social and economic value, capturing the broader human impact that standard economic models overlook.

In Aotearoa New Zealand an estimated 83,000 people are living with dementia mate wareware (dementia), yet around half are without a diagnosis. Alzheimer’s disease accounts for approximately 70% of dementia cases, and with our aging population, the number of New Zealanders living with dementia is projected to almost double to around 170,000 by 2050.1

Up to half of dementia cases may be preventable through early intervention. For people already living with Alzheimer’s disease,1 the report also notes that earlier and more certain diagnosis can enable lifestyle changes that may help delay disease progression – giving people greater opportunity to act while they are able to do so.

In New Zealand there is no single pathway to an Alzheimer’s disease diagnosis, and dementia subtypes are not always consistently differentiated or communicated. This can leave people and whānau uncertain about the cause of symptoms, likely progression and appropriate management.

Clare Hynd, Alzheimers NZ Board member, says there is an urgent and ongoing need for earlier diagnosis of dementia, alongside continued research into prevention, risk reduction, treatments and cures.

“It’s very interesting to see this kind of work being undertaken and we welcome tests that can support earlier diagnosis, provided they are used by expert clinicians and accompanied by appropriate follow-up support for those tested.

“Unfortunately, that support is often unavailable because community dementia services are underfunded.While we are always optimistic, we are also cautiously optimistic. We look forward to the day that optimism is rewarded. In the meantime, anything that meaningfully advances that outcome is good news.”

The research found greater diagnostic certainty could create value through helping people maintain independence, plan earlier for legal, financial and care needs, and stay connected with the relationships and activities that matter to them. The benefits also extend to partners, children and wider whānau.

One partner of a person living with Alzheimer’s disease told researchers: “If you don’t have that diagnosis, you just don’t know what you’re dealing with. And so how do you cope with that?”

Blood-based biomarker testing has the potential to support a more accessible and timely pathway to greater diagnostic certainty. Unlike subjective symptom reporting, blood biomarkers provide objective, measurable data on underlying disease pathology. When considered alongside a person’s signs, symptoms and wider clinical assessment, these simple tests can help rule in or rule out Alzheimer’s pathology at a much earlier stage.

Dr Campbell Le Heron says “It can sometimes be very difficult to determine whether a person’s thinking difficulties are caused by Alzheimer’s disease, another type of neurodegenerative condition, or something else such as depression or anxiety. In these situations, tests that can determine whether the pathological changes of Alzheimer’s are present can be very helpful, but to date access to these highly specialised investigations (which require either a special brain scan or lumbar puncture for spinal fluid analysis), has been limited by both cost and invasiveness. Blood biomarkers show significant promise for improving diagnostic pathways, but they still need to be interpreted within a person’s clinical context.

“Making an accurate and timely diagnosis matters for people. It can reduce uncertainty, refocus management plans, and reduce the need for further investigations. It allows people to plan their lives, making decisions around work, finances or living arrangements. It also allows access to appropriate health and community-based support systems. We are moving towards an era where treatments that modify the course of Alzheimer’s disease become available, but these are likely to be most effective when given early in the disease process, which we know begins many years before people even notice symptoms.

“Our health system needs to prepare for this by establishing streamlined and effective diagnostic pathways for people with cognitive symptoms. An easily accessible blood test that provides information about the presence or absence of underlying Alzheimer’s pathology will be an important part of this process,” says Le Heron.

The report identifies three priorities to maximise the potential value of improved Alzheimer’s disease diagnosis: supporting people to make brain-healthy choices and seek a diagnosis; tailoring testing and information to different populations; and ensuring consistent access to culturally appropriate support wherever people live.

Wing Lam Wong, General Manager at Roche Diagnostics New Zealand says “We commissioned this research because traditional health system metrics only capture part of the picture. Diagnostic certainty is about far more than clinical costs – it delivers objective clarity to patients and whānau, empowering them to make informed decisions early.

“Neurology is a major focus for Roche, and we are deeply committed to pioneering diagnostic solutions that transform how brain health is measured, managed, and supported across New Zealand and the globe.”