Quality Improvement and Clinical Utility PrecivityAD2(TM) Clinician Survey

There is a major unmet need for timely, non-invasive, and low-burden evaluation of patients presenting with mild cognitive impairment (MCI) and dementia. MCI impacts 12-18% of people in the United States over age 60 years (Alzheimer's Association. Mild Cognitive Impairment (MCI) available at https://www.alz.org/alzheimers-dementia/what-is-dementia/related\_conditions/mild-cognitive-impairment. Accessed August 16, 2022). MCI does not substantially interfere with daily activities, although complex functional tasks may be performed less efficiently (Knopman DS, Petersen RC. Mild cognitive impairment and mild dementia: a clinical perspective. Mayo Clin Proc. 2014;89(10):1452-1459. doi:10.1016/j.mayocp.2014.06.019). Approximately 30% of MCI patients have Alzheimer's disease (AD) as a cause of their symptoms (Lopez,OL, Kuller LH, Becker JT, et al. Incidence of dementia in mild cognitive impairment in the cardiovascular health study cognition study. Arch Neurol. 2007;64(3):416-420.doi:10.1001/archneur.64.3.416)). In contrast, dementia is defined by chronic, acquired loss of two or more cognitive abilities caused by brain disease or injury, often associated with significant interference with the ability to function at work or at usual activities. (Knopman DS, Petersen RC. Mild cognitive impairment and mild dementia: a clinical perspective. Mayo Clin Proc. 2014;89(10):1452-1459. doi:10.1016/j.mayocp.2014.06.019). Approximately 60-80% of dementia patients have AD as a cause of their symptoms (Alzheimer's Association. Mild Cognitive Impairment (MCI) available at https://www.alz.org/alzheimers-dementia/what-is-dementia/related\_conditions/mild-cognitive-impairment. Accessed August 16, 2022).

The Quality Improvement PrecivityAD2(TM) Clinician Survey and Clinical Utility Study (QUIP II) represents a large-scale initiative for the PrecivityAD2 blood test for use by neurologists, geriatricians, and geropsychiatrists (memory care specialists) who see patients aged 55 years and older with signs or symptoms of MCI or dementia. C₂N Diagnostics, LLC is a CLIA-certified, CAP-accredited diagnostic testing laboratory based in St. Louis, MO. Its new test, the PrecivityAD2 blood test, measures plasma amyloid beta (Aβ) peptides 42 and 40 (Aβ42/40) Ratio and phosphorylated tau (p-tau) compared to non-phosphorylated tau (np-tau) at amino acid 217 of the tau peptide (p-tau217/np-tau217) ratio to determine whether a patient with signs or symptoms of cognitive impairment is likely to have brain amyloid plaques, a pathological hallmark of AD.