Less than 1 in 4 primary care clinicians report using newer blood-based Alzheimer’s disease tests for patients with suspected cognitive impairment, according to research presented at the American Geriatrics Society (AGS) 2026 Annual Scientific Meeting.

The research also found primary care clinicians who were less confident in diagnosing dementia overall were more likely to refer patients to specialists and not to use one of the biomarker tests, whereas those with higher confidence were more likely to order the tests, highlighting a divide in how clinicians navigate new diagnostic aids for neurocognitive conditions.

“Those who use blood biomarkers could be characterized as technology pioneers, often affiliated with academic settings and, potentially, involved in clinical research,” said Ignacia Arteaga, PhD, assistant researcher at the University of California, San Francisco, who led the research.

The FDA approved the first blood test to detect plasma biomarkers for Alzheimer’s disease in 2025. These typically measure amyloid- and tau-related proteins. Early studies show they can be accurate, but most research has been conducted in specialty clinics rather than primary care settings.

The findings come from an analysis of data from the first wave of the National Dementia Workforce Study, a nationally representative survey conducted from late 2024 to early 2025. The analysis included 1992 community clinicians nationwide, with a little more than half practicing primary care and the remaining from neurology, psychiatry, geriatrics, and neuropsychology.

The use of plasma biomarker testing in primary care was overall limited: 16.7% of these clinicians reported sometimes or routinely ordering the tests for suspected cognitive impairment, which was far lower than use of neuropsychological testing (71.1%) or CT imaging (77.4%), and similar to PET scans (18.4%).

Among primary care clinicians, 21.7% reported low confidence in diagnosing dementia in adults aged 65 years or older, and 41.2% reported low confidence in diagnosing Alzheimer’s disease.

Lower confidence in diagnosing dementia and Alzheimer’s disease was associated with a small but statistically significant increase in referrals to neurologists. In contrast, clinicians with higher confidence were somewhat more likely to use plasma biomarker tests, although the relationship was modest (r = 0.20-0.24, P < .001).

Most clinicians also did not view results from plasma biomarkers as central to the ongoing care of dementia. Among all clinicians, 72% rated them a low priority, and 18% were unsure. Many researchers say the tests are not yet ready for population-based screening because of a lack of effective treatment at early stages of the disease.

“They are hesitant to embrace the plasma biomarker testing opportunity because the blood test does not help with management,” Arteaga said. “If nothing changes in terms of actionability after testing, PCPs [primary care providers] may not see the value.”

Many older adults also have more than one potential cause of cognitive symptoms, making interpretation harder with a positive or borderline result.

Clinicians often reserve testing for specific cases or patient-driven requests, she said.

“They would only prescribe it if patients or relatives are pushing for it, or because [clinicians] are seeking access to anti-amyloid therapies,” she said.

Charles Vega, MD, clinical professor of family medicine at the University of California, Irvine, who was not involved in the study, said more primary care clinicians should be utilizing the tests along with a full clinical evaluation.

But Vega said the tests should only be ordered for patients who present with symptoms of dementia, “where you suspect Alzheimer’s disease is in the differential,” he said.

Balancing Diagnosis and Referral

Primary care clinicians are increasingly responsible for conducting early diagnostic workups when symptoms of dementia first emerge.

“Primary care is in a really hard place,” Vega said. While he prefers specialist input “there’s just not nearly enough of those specialists, so the wait time is months. We really have to do the initial inquiry, the screening, the basic workup, and now we should include biomarker” tests, he said.

Use of plasma biomarkers is expected to increase as regulatory approvals expand, insurance coverage improves, and demand grows.

“Primary care clinicians are expected to increasingly discuss, prescribe, and explain blood-based biomarker results,” Arteaga said.

Vega said the tools could eventually reduce reliance on specialists.

But Vega cautioned that rapid adoption without sufficient guidance could create new risks, including overdiagnosis, unnecessary follow-up testing, and misinterpretation of results.

“I don’t think the tests are done being developed yet,” Vega said.

Arteaga and Vega disclosed having no relevant conflicts of interest.

Lara Salahi is a health journalist based in Boston.