Earlier Blood Biomarker Disclosure Increases Diagnostic Certainty in Memory Clinic Trial

A prospective randomized trial published in JAMA Neurology evaluated whether earlier disclosure of blood biomarkers changed diagnostic certainty, management, and emotional outcomes in patients with cognitive symptoms. At a single Spanish memory clinic, 220 patients with subjective cognitive decline, mild cognitive impairment, or mild dementia received plasma p-tau217 and neurofilament light chain results at either 3 or 9 months, alongside standard evaluation. Median age was 73 years; follow-up lasted 9 months.

At 3 months, an etiologic diagnosis with at least 90% confidence was achieved in 56 of 112 patients receiving earlier disclosure (50.0%), compared with 5 of 108 receiving delayed disclosure (4.6%; P<.001). Symptomatic Alzheimer disease treatment was initiated more frequently with earlier disclosure (14.3% vs 4.6%). Planned neuropsychological reassessments for diagnostic clarification were less frequent (30.4% vs 52.8%), while planned discharge to primary care was more frequent (31.3% vs 12.0%).

Diagnostic certainty converged after both groups received results, except among patients with mild cognitive impairment, for whom higher certainty persisted in the earlier-disclosure group. Earlier disclosure was not associated with worse anxiety, depression, perceived stress, or quality-of-life outcomes. The findings support a potential role for these biomarkers in memory clinic pathways, but increased confidence does not establish diagnostic accuracy or improved long-term clinical outcomes. The single-center setting limits generalizability; only the abstract was available for this report.