Plasma-biomarker rollout is concentrated at academic centers

Plasma p-tau217 was meant to compress diagnostic friction - pulling biomarker confirmation out of the PET scanner and into the phlebotomy chair. The clinical performance has supported that. The geography of adoption has not yet followed.

Published utilization data and health-system reports describe a pattern in which:

• Academic medical centers and large specialty memory clinics have integrated plasma testing into structured workup pathways.
• Mid-sized community neurology and primary-care groups have meaningful but inconsistent adoption - often dependent on a single champion clinician or a specific lab partnership.
• Smaller practices, particularly in rural areas, have minimal adoption.

The risk is straightforward: a test that should have democratized diagnosis ends up reproducing the same access geography that amyloid PET created - concentrated where cognitive specialists and supporting infrastructure already exist. The downstream effect on treatment-eligible identification is uneven.

Two operational levers are worth tracking: payer coverage of plasma assays in primary care, and structured education programs that bring diagnostic workflow guidance to community clinicians. Both are early; neither is at scale.

The broader question is whether the widening of diagnostic access keeps pace with the widening of treatment access - or whether the gap simply moves upstream.