@article{16cbe094d5f34b8ba187d8c1e5048c19,
title = "Parallel but not equivalent: Challenges and solutions for repeated assessment of cognition over time",
abstract = "Objective. Analyses of individual differences in change may be unintentionally biased when versions of a neuropsychological test used at different follow-ups are not of equivalent difficulty. This study's objective was to compare mean, linear, and equipercentile equating methods and demonstrate their utility in longitudinal research. Study design and setting: The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE, N=1,401) study is a longitudinal randomized trial of cognitive training. The Alzheimer's Disease Neuroimaging Initiative (ADNI, n=819) is an observational cohort study. Nonequivalent alternate versions of the Auditory Verbal Learning Test (AVLT) were administered in both studies. Results. Using visual displays, raw and mean-equated AVLT scores in both studies showed obvious nonlinear trajectories in reference groups that should show minimal change and poor equivalence over time (ps.001), and raw scores demonstrated poor fits in models of within-person change (root mean square errors of approximation, RMSEAs > 0.12). Linear and equipercentile equating produced more similar means in reference groups (ps.09) and performed better in growth models (RMSEAs < 0.05). Conclusion. Equipercentile equating is the preferred equating method because it accommodates tests more difficult than a reference test at different percentiles of performance and performs well in models of within-person trajectory. The method has broad applications in both clinical and research settings to enhance the ability to use nonequivalent test forms.",
keywords = "Alternate forms, Equating, Equipercentile, Longitudinal analysis, Neuropsychology, Parallel forms",
author = "Gross, {Alden L.} and Inouye, {Sharon K.} and Rebok, {George W.} and Jason Brandt and Crane, {Paul K.} and Parisi, {Jeanine M.} and Doug Tommet and Karen Bandeen-Roche and Carlson, {Michelle C.} and Jones, {Richard N.}",
note = "Funding Information: ∗Data used in preparation of this article were obtained from the Alzheimer{\textquoteright}s Disease Neuroimaging Initiative (ADNI) database (adni.loni.ucla.edu). As such, the investigators within the ADNI contributed to the design and implementation of ADNI and/or provided data but did not participate in analysis or writing of this report. A complete listing of ADNI investigators can be found at: http:// adni.loni.ucla.edu/wpcontent/uploads/how_to_apply/ADNI_Acknowledgement_List.pdf Alden L. Gross was supported by a National Institutes of Health Translational Research in Aging fellowship (T32AG023480-07). Sharon K. Inouye holds the Milton and Shirley F. Levy Family Chair in Alzheimer{\textquoteright}s Disease. This work was supported in part by Grant P01AG031720 (S.K.I.) from the National Institute of Aging. George W. Rebok is an investigator with Compact Disc Incorporated for the development of an electronic version of the ACTIVE memory intervention. He has received no financial support from them for ACTIVE. Jason Brandt receives royalty income from Psychological Assessment Resources, Inc., on sales of the Hopkins Verbal Learning Test–Revised. George W. Rebok{\textquoteright}s and Jason Brandt{\textquoteright}s relationships are managed by the Johns Hopkins University according to its established conflict of interest policies. The ACTIVE intervention trials are supported by grants from the National Institute on Aging and the National Institute of Nursing Research to Hebrew Senior Life (U01NR04507), Indiana University School of Medicine (U01NR04508), Johns Hopkins University (U01AG14260), New England Research Institutes (U01AG14282), Pennsylvania State University (U01AG14263), the University of Alabama at Birmingham (U01 AG14289), and the University of Florida (U01AG14276). Data collection and sharing for this project were funded by the Alzheimer{\textquoteright}s Disease Neuroimaging Initiative (ADNI; National Institutes of Health Grant U01 AG024904). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following: Abbott; Alzheimer{\textquoteright}s Association; Alzheimer{\textquoteright}s Drug Discovery Foundation; Amorfix Life Sciences Ltd.; AstraZeneca; Bayer HealthCare; BioClinica, Inc.; Biogen Idec Inc.; Bristol-Myers Squibb Company; Eisai Inc.; Elan Pharmaceuticals Inc.; Eli Lilly and Company; F. Hoffmann-La Roche Ltd and its affiliated company Genentech, Inc.; GE Healthcare; Innogenetics, N.V.; Janssen Alzheimer Immunotherapy Research & Development, LLC.; Johnson & Johnson Pharmaceutical Research & Development LLC.; Medpace, Inc.; Merck & Co., Inc.; Meso Scale Diagnostics, LLC.; Novartis Pharmaceuticals Corporation; Pfizer Inc.; Servier; Synarc Inc.; and Takeda Pharmaceutical Company. The Canadian Institutes of Health Research is providing funds to support ADNI clinical sites in Canada. Private sector contributions are facilitated by the Foundation for the National Institutes of Health (www.fnih.org). The grantee organization is the Northern California Institute for Research and Education, and the study is coordinated by the Alzheimer{\textquoteright}s Disease Cooperative Study at the University of California, San Diego. ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of California, Los Angeles. This research was also supported by National Institutes of Health (NIH) Grants P30 AG010129 and K01 AG030514, and by the Dana Foundation.",
year = "2012",
month = aug,
day = "1",
doi = "10.1080/13803395.2012.681628",
language = "English (US)",
volume = "34",
pages = "758--772",
journal = "Journal of Clinical and Experimental Neuropsychology",
issn = "1380-3395",
publisher = "Psychology Press Ltd",
number = "7",
}