INTRODUCTION List-learning tasks are important for characterizing memory in ADRD research, but the Uniform Data Set neuropsychological battery (UDS-NB) lacks a list-learning paradigm; thus, sites administer a range of tests. We developed a harmonized memory composite that incorporates UDS memory tests and multiple list-learning tasks.

METHODS Item-banking confirmatory factor analysis was applied to develop a memory composite in a diagnostically heterogenous sample (n=5943) who completed the UDS-NB and one of five list-learning tasks. Construct validity was evaluated through associations with demographics, disease severity, cognitive tasks, brain volume, and plasma phosphorylated tau (p-tau181 and p-tau217). Test-retest reliability was assessed. Analyses were replicated in a racially/ethnically diverse cohort (n=1058).

RESULTS Fit indices, loadings, distributions, and test-retest reliability were adequate. Expected associations with demographics and clinical measures within development and validation cohorts supported validity.

DISCUSSION This composite enables researchers to incorporate multiple list-learning tasks with other UDS measures to create a single metric.

B.F.B. has served as an investigator for clinical trials sponsored by Alector, Biogen, Transposon and Cognition Therapeutics. He serves on the Scientific Advisory Board of the Tau Consortium, which is funded by the Rainwater Charitable Foundation. He receives research support from NIH. A.L.B. receives research support from the NIH, the Tau Research Consortium, the Association for Frontotemporal Degeneration, Bluefield Project to Cure Frontotemporal Dementia, Corticobasal Degeneration Solutions, the Alzheimers Drug Discovery Foundation and the Alzheimers Association. He has served as a consultant for Aeovian, AGTC, Alector, Arkuda, Arvinas, Boehringer Ingelheim, Denali, GSK, Life Edit, Humana, Oligomerix, Oscotec, Roche, TrueBinding and Wave and received research support from Biogen, Eisai and Regeneron. M.M.G. reports personal stock in Abbvie. R.C.P. reports personal fees from Roche, no personal fees from Eisai, and personal fees from Genentech, personal fees from Eli Lilly and personal fees from Nestle, outside the submitted work. B.L.M reported serving on the scientific advisory board of the Bluefield Project to Cure Frontotemporal Dementia; the John Douglas French Alzheimers Foundation; Fundación Centro de Investigación Enfermedades Neurológicas, Madrid, Spain; Genworth; the Kissick Family Foundation; the Larry L. Hillblom Foundation; and the Tau Consortium of the Rainwater Charitable Foundation; serving as a scientific advisor for the Arizona Alzheimers Consortium; Massachusetts General Hospital Alzheimers Disease Research Center; and the Stanford University Alzheimers Disease Research Center; receiving royalties from Cambridge University Press, Elsevier, Guilford Publications, Johns Hopkins Press, Oxford University Press, and the Taylor & Francis Group; serving as editor for Neurocase and section editor for Frontiers in Neurology; and receiving grants for the University of California San Francisco Frontotemporal Dementia Core, from the Bluefield Project to Cure Frontotemporal Dementia, and from the National Institute on Aging for the US South American Initiative for Genetic-Neural-Behavioral Interactions in Human Neurodegenerative Diseases. G.D.R. reported grants from National Institutes of Health during the conduct of the study; consulting fees from C2N, Eli Lilly, Alector, Merck, Roche, and Novo Nordisk; data safety monitoring board fees from Johnson & Johnson; and grants from Avid Radiopharmaceuticals, GE Healthcare, Life Molecular Imaging, and Genentech outside the submitted work; and served as Associate Editor at JAMA Neurology. A.M.S. reported grants from the National Institutes of Health, the Bluefield Project to Cure Frontotemporal Dementia, and the Association for Frontotemporal Degeneration; personal fees from Alector, Prevail Therapuetics/Eli Lilly, Passage Bio, Takeda, and the Alzheimers Drug Discovery Foundation; and other from Datacubed Health (licensing fees) outside the submitted work. H. J. R. reported consulting fees from Genentech and Eisai outside the submitted work. Dr Staffaroni reported grants from the National Institutes of Health, the Bluefield Project to Cure Frontotemporal Dementia, and the Association for Frontotemporal Degeneration; personal fees from Alector, Prevail Therapuetics/Eli Lilly, Passage Bio, Takeda, and the Alzheimers Drug Discovery Foundation; and other from Datacubed Health (licensing fees) outside the submitted work. C.D. serves as a consultant to Norvo Nordisk and Eisai Pharmaceuticals. D.K.J. has stock holdings in Sage Cerebrovascular Diagnostics, serves as President for Sage Cerebrovascular Diagnostics, and has a patent pending for Serologic assay for silent brain ischemia licensed to Sage Cerebrovascular Diagnostics

Data collection and dissemination of the data presented in this manuscript was supported by the LEADS Consortium (R56/U01 AG057195, funded by the National Institute on Aging); ALLFTD Consortium (U19: AG063911, funded by the National Institute on Aging and the National Institute of Neurological Diseases and Stroke) and the former ARTFL & LEFFTDS Consortia (ARTFL: U54 NS092089, funded by the National Institute of Neurological Disorders and Stroke and National Center for Advancing Translational Sciences; LEFFTDS: U01 AG045390, funded by the National Institute on Aging and the National Institute of Neurological Diseases and Stroke); and the DVCID study (U19NS120384; jointly supported by the National Institute of Neurological Disorders and Stroke and the National Institute on Aging). This project was also generously funded by the National Institute of Health (P30AG053760, R35AG072262).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Study procedures for the LEADS consortium were approved by the Indiana University IRB. Study procedures for the ALLFTD consortium were approved by Johns Hopkins Central IRB. Procedures for other consortia (MarkVCID, Diverse VCID) were approved by site IRB and ethics review boards. Consortia sites include: Johns Hopkins University, Rush Medical Center/Illinois Institute of Technology, Universities of California San Francisco, Davis, and Los Angeles, University of Kentucky, University of Southern California, University of New Mexico Health Sciences Center, Cohorts for Heart and Aging Research in Genomic Epidemiology [CHARGE] consortium, Cedars Sinai Goldrich Center for Alzheimer's & Memory Disorders, University of Alabama at Birmingham, University of Miami, Wake Forest University, Columbia University, New York University, University of Texas, The University of Texas Rio Grande Valley, University of Wisconsin, University of Colorado Denver, Mayo Clinic (Florida, Minnesota), Emory University, Northwestern University, Massachusetts General Hospital, Washington University in St. Louis, Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, Mount Sinai, University of North Carolina Chapel Hill, Case Western Reserve Medical Center, Brown University, Vanderbilt University, Nantz National Alzheimer Center, National institute of health/national institute of neurological disorders and stroke, University of Washington, University of British Columbia, and the University of Toronto.

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