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O4–08–01: Association between the Alzheimer's disease–related hypometabolic convergence index and clinical ratings in cognitively normal older adults with and without significant fibrillar amyloid burden: Findings from the Alzheimer's Disease Neuroimaging Initiative
Author(s) -
Roontiva Auttawut,
Chen Kewei,
Ayutyat Napatkamon,
Protas Hillary,
Liu Xiaofen,
Thiyyagura Pradeep,
Lee Wendy,
Reschke Cole,
Parks Stephanie,
Bauer Robert,
Koeppe Robert,
Jagust William,
Foster Norman,
Weiner Michael,
Fleisher Adam,
Reiman Eric
Publication year - 2013
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2013.04.377
Subject(s) - dementia , amyloid (mycology) , medicine , neuroimaging , positron emission tomography , pittsburgh compound b , beta (programming language) , senile plaques , amyloid beta , alzheimer's disease , disease , standardized uptake value , psychology , pathology , audiology , neuroscience , nuclear medicine , computer science , programming language
Coordinating Center (NACC; N1⁄4869), Religious Orders Study (ROS; N1⁄4174), Rush Memory and Aging Project (MAP; N1⁄4149), clinical trial of the drug Tarenflurbil (N1⁄42,524), AddNeuroMed study (N1⁄4303), and Adult Changes in Thought (ACT; N1⁄4746). First, we performed pre-statistical harmonization to identify tests in common across studies. Second, we used a two parameter graded-response item response theory model to estimate cognitive ability scores for each observation at all time points in all studies. Results: The cognitive composite was normally distributed and scaled to have mean1⁄450 and standard deviation1⁄410. The median followup time in the pooled sample was 3.1 years (range: 0-18 years). The cognitive composite had interval-level properties, was highly internally consistent (Cronbach’s alpha1⁄40.88), had minimal floor or ceiling effects, and demonstrated reliable measurement precision over a broad range of ability levels (See Figure.).Conclusions:Our methods can be used to calibrate neuropsychological test results across diverse settings and studies into a summary measure of global cognitive functioning. Psychometric properties of the measure holds substantial promise for advancing work to evaluate cognitive decline over time in persons with AD, making it an optimal phenotype for a GWAS of cognitive decline.