Suzanne E. Schindler, MD, PhD - AAIC 2026: Advancing Alzheimer’s Disease Detection, Diagnosis, and Treatment Through New Evidence

So let's go to our first challenge question.

According to data presented at AAIC twenty twenty-six from the BioFINDER Primary Care Study, when a blood-based biomarker test was integrated into the primary care workflow, what was its impact on the diagnosis of Alzheimer's disease? Number one, did blood-based biomarker testing have a minimal impact on primary care providers' diagnoses, less than a ten percent change, but improved diagnostic certainty? Or did primary care providers change their diagnosis in approximately twenty percent of patients after blood-based biomarker testing, but their overall level of diagnostic certainty decreased because of the high reads of intermediate or likely positive test results? Or did blood-based biomarker testing improve primary care providers' diagnostic accuracy by over twenty-five percent, and their negative predictive value for ruling out Alzheimer's disease became similar to that of dementia experts? Or did primary care providers change their diagnoses in more than sixty percent of patients but didn't meaningfully change their clinical management decisions? Or finally, I'm not sure.

So what do you think was found? So, uh, the answer is that blood-based biomarker testing improved primary care providers' diagnostic accuracy by over twenty-five percent, and their negative predictive value for ruling out Alzheimer's disease became similar to that of dementia experts.

We'll now take a look at some of the data that addresses that issue.

Sebastian Palmqvist presented data from the BioFINDER primary care cohort, and they evaluated how blood-based biomarkers affect the diagnosis and clinical management of patients seen in primary care.

They started by assessing patients who were presenting with, uh, cognitive impairment to primary care providers.

The primary care provider did a clinical assessment, a brief global cognitive test, and then structural imaging, then, uh, wrote down what they thought the diagnosis was.

The patient then underwent a blood test, and based on the results of the blood test, the primary care provider again considered what the likely diagnosis was.

Uh, the patient later was assessed by a dementia specialist and underwent either CSF or PET testing and a expert consensus diagnosis that was used as the, the gold standard.

So they found, uh, some interesting results.

One is that after the blood test, primary care providers and dementia specialists frequently changed the patient's diagnosis, about thirty percent of the time in primary care, about twenty-seven percent of the time, uh, when the patient was seen by a dementia specialist.

Uh, what this underscores is that it's really difficult to assess whether a patient has Alzheimer disease or not until you do some kind of biomarker testing.

Um, another key point is that they found that while primary care providers were only accurate about sixty-two percent of the time before they did the blood test, after they did the blood test, their accuracy rose to about eighty-eight percent.

Uh, so it really improved the accuracy of, of diagnosing whether patients had Alzheimer disease or not, and it was close to the level seen by a dementia specialist, so only about five percentage points difference.

So, so really this is, is showing that by using a blood test, the primary care providers can get pretty close to a dementia specialist just by integrating their clinical assessment and the results of that blood test.

The study also assessed, uh, how certain the clinician felt in the diagnosis [clears throat] and they- See that patients who had either a clear-cut negative or a positive result, uh, this result really increased the clinician's certainty.

Um, the, uh, one exception was patients who had a likely positive or intermediate result.

For dementia specialists, that, that didn't increase diagnostic certainty, which, which makes sense because that's really a, a borderline result.

One additional point is that primary care providers really felt that the use of these blood tests improved their diagnoses.

On a scale of one to ten, uh, they felt that the test was a nine in terms of helping them reach an accurate diagnosis.

Probably the most important finding of the study is that these blood tests had a major impact on clinical management.

So not just understanding whether Alzheimer's disease was the cause of cognitive impairment, but, but what the clinician did with that information.

So it impacted what other tests were performed, whether medications were started or stopped.

So this is, uh, really important information.