title: A blood screening test for Alzheimer's disease.
abstract: BACKGROUND
  This study combined data across four independent cohorts to examine the positive and negative predictive values of an Alzheimer's disease (AD) blood test if implemented in primary care.
  
  
  METHODS
  Blood samples from 1329 subjects from multiple independent, multiethnic, community-based, and clinic-based cohorts were analyzed. A "locked-down" referent group of 1128 samples was generated with 201 samples randomly selected for validation purposes. Random forest analyses were used to create the AD blood screen. Positive (PPV) and negative (NPV) predictive values were calculated.
  
  
  RESULTS
  In detecting AD, PPV was 0.81, and NPV was 0.95 while using the full AD blood test. When detecting mild cognitive impairment, PPV and NPV were 0.74 and 0.93, respectively. Preliminary analyses were conducted to detect any "neurodegenerative disease". The full 21-protein AD blood test yielded a PPV of 0.85 and NPV of 0.94.
  
  
  CONCLUSIONS
  The present study creates the first-ever multiethnic referent sample that spans community-based and clinic-based populations for implementation of an AD blood screen.
authors.affiliation: Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: Sid E
authors.initials: SE
authors.lastname: O'Bryant
authors.affiliation: Department of Psychology, University of North Texas, Denton, TX, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Edwards
authors.affiliation: Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: Leigh
authors.initials: L
authors.lastname: Johnson
authors.affiliation: Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: James
authors.initials: J
authors.lastname: Hall
authors.affiliation: Centro de Neurociencias y Unidad de Investigación Clínica, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Ciudad del Saber, Panamá, Panamá; Department of Biotechnology, Acharya Nagarjuna University, Guntur, India.
authors.forename: Alcibiades E
authors.initials: AE
authors.lastname: Villarreal
authors.affiliation: Centro de Neurociencias y Unidad de Investigación Clínica, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Ciudad del Saber, Panamá, Panamá
authors.forename: Gabrielle B
authors.initials: GB
authors.lastname: Britton
authors.affiliation: Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Quiceno
authors.affiliation: Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: C Munro
authors.initials: CM
authors.lastname: Cullum
authors.affiliation: Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Neill R
authors.initials: NR
authors.lastname: Graff-Radford
keywords: Alzheimer's disease; Blood test; Diagnosis; Predictive power; Primary care; Screening