Recent advances in Blood Based Biomarkers (BBBMs) have paved the way for the early detection of Alzheimer’s disease (AD) in a more efficient way than the current gold-standard techniques. pTau181 assays have a high Negative Predictive Value (NPV) for ruling out the presence of amyloid pathology in the brain, whilst pTau217 assays have demonstrated acceptable performance in ruling in or out amyloid pathology in the brain. The aim of this study is to understand how these BBBMs impact GPs confidence in managing patients with cognitive impairment and confidence in ordering and interpreting these tests.

The study recruits GPs (working in Scotland) and patients (aged 55-80 years, subjective or objective memory impairment, and have not received advanced secondary diagnostics for AD). GP surgeries are cluster randomised to receive either plasma pTau181 or pTau217 results for their patients. The primary outcome measure is GP confidence in managing this patient group, measured at baseline and end of study. Patients will attend the research site for blood samples and health resource use and quality of life questionnaires. Patients will receive their results from their GP. Focus groups at the end of the study will explore patient and GP experiences.

51 GPs have consented to the study (41 NHS and 7 private providers), across 14 different practices. Baseline confidence data for the group and by provider type is presented here. Patient participant recruitment and data collection has started, with baseline results expected later this year.

This ongoing study will provide critical evidence on whether blood-based biomarkers could be used in a primary care setting in the UK, and if indicated provide guidance on how they can best be embedded. Findings to date suggest GPs have the potential to improve their confidence in their clinical abilities and engagement with this group. This study will determine whether blood-based biomarker results can be a way to increase these confidence levels. Baseline patient data collection will be completed in 2026, with final study results expected in 2027.