- A blood test for Alzheimer’s disease biomarkers helped improve diagnostic accuracy among specialists and primary care physicians in a real-world study.
- In a head-to-head comparison after reviewing blood test results, primary care physicians and specialists both had a diagnostic accuracy of around 90%.
- For primary care physicians, the test was most helpful in ruling out Alzheimer’s disease.
LONDON, July 14, 2026 /PRNewswire/ — Knowledge of blood test results enables primary care physicians to diagnose Alzheimer’s disease with essentially the same accuracy as specialists, a major step toward expanding access to an accurate diagnosis for millions of patients, suggests new data reported for the first time at the Alzheimer’s Association International Conference® (AAIC®) 2026 in London and online.
In one of the first real-world studies of its kind — including more than 1,300 patients and 165 physicians — researchers found that a blood-based biomarker test significantly improved the accuracy of Alzheimer’s diagnosis in both primary and specialty care settings. The test measures amyloid beta and phosphorylated tau, both of which are abnormal brain proteins linked to Alzheimer’s disease.
In a direct comparison among primary care patients, primary care physicians achieved nearly the same diagnostic accuracy as dementia specialists — around 90% for both. After seeing the blood test results, the physicians changed diagnoses in about one-third of the patients and changed their plans for future care and examinations for more than half of the patients.
“We wanted to find out whether a simple blood test for Alzheimer’s changes how doctors actually diagnose and manage their patients in everyday clinical care,” said Sebastian Palmqvist, M.D., Ph.D., lead author of the study, neurologist and associate professor of neurology at Lund University, Sweden. “Accurate Alzheimer’s diagnosis has largely been limited to specialist settings. Our findings show that this blood test could bring that level of accuracy into primary care, where most patients are first seen, closing the gap between primary care and specialty care.”
The blood test was most useful in primary care for ruling out Alzheimer’s, Dr. Palmqvist said. Primary care clinicians remained cautious about using it to diagnose the disease, preferring to send their patients to a specialist for confirmation, as is appropriate, he noted.
Today, the standard of care for confirming Alzheimer’s disease involves specialized tests such as PET scans (brain imaging) and spinal fluid analysis, tools that are often costly and not widely available outside of memory clinics.
“This is hopeful news for patients, who often face delays, referrals and long wait times before receiving a clear diagnosis and treatment,” said Sheena Aurora, M.D., Alzheimer’s Association vice president of medical affairs. “The results suggest highly accurate blood tests can change — even improve — diagnosis and medical management in primary and secondary care, meaning doctors all along the care continuum may find them useful. This study strongly suggests there is great clinical utility for this test.”
The interim results from the study included 1,310 patients with mild cognitive impairment (MCI) or dementia in Sweden, including 927 evaluated by specialists and 383 evaluated in primary care. The patients seen in primary care were also independently assessed by dementia specialists, enabling a head-to-head comparison of diagnostic accuracy between primary care physicians and specialists. To measure real-world impact on clinical decision-making, researchers compared physicians’ working diagnoses and management plans before and after receiving results from the PrecivityAD2™ blood test.
The researchers used cerebrospinal fluid analysis, amyloid PET and a consensus diagnosis by dementia experts to assess the accuracy of the diagnoses. In the interim analysis, the specialists’ diagnostic accuracy rose from 74% before to 89% after receiving the blood test results. In the primary care group, primary care physicians’ diagnostic accuracy rose from 65% before to 93% after receiving blood test results. In a head-to-head comparison of those patients, specialists achieved 94% accuracy after receiving the blood test results.
Additionally, primary care clinicians changed their diagnoses for 30% of patients, with the greatest impact seen in ruling out Alzheimer’s as the cause of the patients’ cognitive issues. Their willingness to rule out Alzheimer’s increased from 12.9% to 25% after a negative test result. Dementia experts changed their diagnosis in 21.6% of patients and were far more likely to make an immediate Alzheimer’s diagnosis without additional testing when the test was positive (1.9% to 55.4%).
After receiving the blood test results, clinical management was revised in about half of the cases, both in primary and secondary care, including changes to referrals, additional testing and treatment decisions.
“A negative result helped primary care physicians confidently rule out Alzheimer’s and look for other causes of the symptoms,” Dr. Palmqvist said. “It’s important to remember that these blood tests are designed specifically to detect Alzheimer’s, so patients with negative results may still have other neurological conditions and may still be suitable for referral to a specialist for further evaluation.”
To guide primary care clinicians in the appropriate use of blood biomarker tests, the Alzheimer’s Association is preparing a concise decision-making tool to be posted on ALZPro®, its central hub of professional resources. The Association has also published Clinical Practice Guidelines that provide clear, evidence-based, brand-agnostic recommendations to support appropriate use of blood tests in specialty care in people experiencing dementia symptoms.
“Because not all blood-based biomarker tests meet the same standards for accuracy, clear evidence-based guidance is essential,” Dr. Aurora said. “These tools help clinicians make informed decisions about using the right blood-based biomarker test for the right patient at the right time.”
About AAIC
AAIC is the world’s largest gathering of researchers from around the world focused on Alzheimer’s and other diseases that cause dementia. As a part of the Alzheimer’s Association’s research program, AAIC serves as a catalyst for generating new knowledge about dementia and fostering a vital, collegial research community.
- AAIC 2026: alz.org/aaic
- AAIC 2026 newsroom: alz.org/aaic/pressroom.asp
- AAIC 2026 hashtag: #AAIC26
About the Alzheimer’s Association
The Alzheimer’s Association is a worldwide voluntary health organization dedicated to Alzheimer’s care, support and research. Our mission is to lead the way to end Alzheimer’s and all other dementia — by accelerating global research, driving risk reduction and early detection, and maximizing quality care and support. Our vision is a world without Alzheimer’s and all other dementia®. Visit alz.org or call +1 800.272.3900.
View original content to download multimedia:https://www.prnewswire.com/news-releases/alzheimers-blood-test-could-bring-highly-accurate-diagnosis-into-everyday-clinical-care-302824484.html
SOURCE Alzheimer’s Association
