Expanding Access to Cognitive Health Biomarker Testing at Home

Alzheimer's disease (AD) and related dementias are among the most urgent public health challenges, with more than six million Americans currently affected. Early detection is critical to improving outcomes, yet diagnosis is often delayed until symptoms interfere with daily functioning and specialty evaluation is obtained. Blood-based biomarkers, particularly phosphorylated tau-217 (p-tau217), represent a transformative advancement, offering accurate, scalable, and minimally invasive alternatives to cerebrospinal fluid assays and PET imaging. However, their feasibility in remote, population-based workflows remains largely untested.

This study will enroll a prospective, remotely recruited cohort of older adults with subjective cognitive concerns or possible mild cognitive impairment to evaluate the clinical and operational feasibility and acceptability of at-home p-tau217 testing. This project targets individuals at elevated risk for dementia progression but without a formal diagnosis.

After consent, participants will complete brief baseline online surveys and receive an at-home blood collection kit. The kit contains a single-use Tasso capillary blood sampling kit, illustrated written and video instructions, prepaid return packaging, and a customer support contact. Participants self-collect capillary blood from the upper arm and return the sample to a CLIA-certified laboratory (Neurogen Biomarking/AccessDx Laboratory) for p-tau217 immunoassay analysis. All results are reviewed by a board-certified neurologist independent of the study team and classified as positive, negative, or intermediate. Negative results are shared via email, and intermediate or positive results include neurologist disclosure of results to the participant via secure videoconference or telephone, explanation of the meaning and limitations of the result, and, when applicable, recommendation and facilitation of referral for confirmatory testing or specialty evaluation.

Participants complete a post-disclosure acceptability survey within 2 weeks of results disclosure, and a follow-up survey at 6 months post-disclosure, to capture downstream specialty evaluation, confirmatory testing, and treatment initiation. The total per-participant duration is \~6-7 months. By operationalizing a fully remote biomarker workflow, the study aims to inform scalable, patient-centered pathways for early AD diagnosis, especially among rural and underserved populations facing geographic, workforce, and cost barriers to specialty dementia care.