ABSTRACT
Introduction: We aimed to characterize the clinical impact of amyloid PET (APET) in a veteran population with cognitive decline by comparing differences in management between those who did and did not have an APET. Methods: This was a retrospective observational study. Poisson regressions and logistic regression were used for comparisons. Results: Out of 565 veterans, 197 underwent APET; positivity rate was 36.55%. Having an APET was associated with longer follow-up, and increased diagnostic variability; it was not associated with number of additional studies, cholinesterase inhibitors prescription, or referrals to research. A positive APET was associated with less diagnostic variability, fewer additional tests, greater cholinesterase inhibitor prescriptions, and more research referrals. Discussion: In a medically complex, real-world population, APET yielded lower positivity rates and was not associated with classical clinical utility variables when comparing patients with and without an APET. APET may be used more to "rule out" rather than to confirm Alzheimer's disease. Highlights: Amyloid PET was associated with longer follow-up, and higher diagnostic variability.No association was seen with cholinesterase inhibitors prescription, or referrals to research.In complex patients, expected amyloid PET positivity rates are lower than previously described.Amyloid PETs were used to "rule out" AD than to confirm the diagnosis of AD.
