Optimizing baseline and post-concussion assessments through identification, confirmation, and equivalence of latent factor structures: Findings from the NCAA-DoD CARE Consortium

Abstract

Objective: Concussion evaluations use a multidimensional assessment to evaluate unique patient function dimensions (e.g., subjective symptoms differ from balance assessments), but the overarching latent factor structure has not been empirically substantiated. Our objective was to determine the cumulative latent factor structure of pre-injury baseline and acute (<48-h) post-concussion assessment battery outcomes, and determine measurement equivalence among common factors in collegiate student-athletes. Methods: Collegiate student-athletes at baseline (n = 21,865) and post-concussion (n = 1,537) across 25-institutions completed standardized assessments. Individual items were used from the baseline and post-concussion assessments and consisted of: Sport Concussion Assessment Tool, Brief Symptom Inventory-18, Standardized Assessment of Concussion, Balance Error Scoring System, Immediate Post-Concussion Assessment and Cognitive Test, and vestibular-ocular motor screening. Exploratory factor analysis was used on half the baseline data, and confirmatory factor analysis on the remaining baseline data and post-concussion data separately. Measurement equivalence was assessed between sex, sport contact classification, concussion history, and time. Results: A 10-factor exploratory model was established and comprised of: depression, somatic, vestibulo-ocular, headache, postural stability, neurocognition, emotional, fatigue, cognitive, consciousness clouding. The 10-factor model was confirmed at baseline and post-concussion with strong measurement equivalence between timepoints. Strong to strict measurement equivalence was observed for sex, sport contact classification, and concussion history at both timepoints separately. Conclusion: Our findings established a robust 10-factor latent factor model equivalent across timepoints and common factors among healthy and concussed collegiate athletes. Clinicians can use these findings to target specific factors while reducing redundant elements to provide efficient, comprehensive post-concussion assessments.

Keywords:

• Factor analysis
• neurocognitive testing
• symptoms
• postural stability
• oculomotor

Acknowledgements

The authors would also like to thank Jody Harland, Janetta Matesan, Michael Menser (Indiana University School of Medicine); Ashley Rettmann, Nicole L’Heureux, (University of Michigan); Melissa McEachern (Medical College of Wisconsin); Michael Jarrett, Vibeke Brinck, and Bianca Byrne, (Quesgen); Melissa Baker, Christy Collins, Will Felix, Bethany Morath, (Datalys Center for Sports Injury Research and Prevention); and the research and medical staff at each of the CARE participation sites. We are grateful for the participation of the student athletes without whom this research would not be possible.

Contributing CARE Consortium Investigators include: April Reed Hoy, MS, ATC (Azusa Pacific University), Christina L. Master, MD (Children’s Hospital of Philadelphia), Christopher D’Lauro, PhD (United States Air Force Academy), Kenneth L. Cameron, PhD, MPH, ATC (United States Military Academy), Adam Susmarski, DO (United States Naval Academy), Joshua T. Goldman, MD, MBA (University of California Los Angeles), Thomas A. Buckley, EdD, ATC and Thomas. W. Kaminski, PhD, ATC (University of Delaware), Justus Ortega, PhD (Humboldt State University), Nicholas Port, PhD (Indiana University), Luis A. Feigenbaum, DPT, ATC (University of Miami), James T. Eckner, MD (University of Michigan), Jason P. Mihalik, PhD, ATC (University of North Carolina at Chapel Hill), Jane McDevitt, PhD, ATC (Temple University), Stefan M. Duma, PhD (Virginia Tech University), Christopher M. Miles, MD (Wake Forest University).

Author contributions

All authors contributed to the study conception, study design, critical review, and interpretation of findings, and drafting and/or critique of the manuscript. All authors read and approved the final manuscript. Specifically, Landon B. Lempke contributed to conceptualization, methodology, data analysis and interpretation, and original and revised manuscript drafts. Gian-Gabriel P. Garcia contributed to conceptualization, data interpretation, and original and revised manuscript drafts. Adrian J. Boltz, Reid Syrydiuk, and Himadri Pandey contributed to data interpretation, and original and revised manuscript drafts. Steven Broglio, Michael A. McCrea and Thomas W. McAllister contributed to conceptualization, methodology, data interpretation, original and revised manuscript drafts, and funding acquisition. The CARE Consortium Investigators contributed to critical review of the original manuscript.

Availability of data and material

The CARE Consortium datasets generated and analyzed during the current study are available in the FITBIR repository (https://fitbir.nih.gov/).

Disclosure statement

All disclosures below are not directly related to the current project, but are reported for full transparency to readers. Dr. Landon Lempke has current or prior funding unrelated to the current project from the National Athletic Trainers’ Association (NATA), American College of Sports Medicine (ACSM), both the Southeast and Eastern Athletic Trainers’ Associations, VALD, internally from university affiliations, has received various speaker honorarium and travel reimbursement for talks given, and works on projects funded by the Department of Defense (DoD), National Collegiate Athletic Association (NCAA), and National Football League (NFL). Mr. Adrian Boltz has worked on projects that been funded by the DoD, National Operating Committee on Standards from Athletic Equipment, NATA, and NCAA. Dr. Michael McCrea has received research funding from the NIH, CDC, DoD, NCAA, NFL, and Abbott Laboratories. Dr. Thomas McAllister reports current or prior grant support from NIH, DoD, and NCAA, as well as textbook royalties from the “Textbook of Traumatic Brain Injury” from the American Psychiatric Association Publishing, Inc., and is an unpaid member for the concussion Scientific Advisory Committee for the Australian-Rules Football Conference. Dr. Steven Broglio has current or past research funding from the NIH, CDC, DoD, NCAA, NATA, NFL/Under Armour/GE; Simbex; and ElmindA. Dr. Broglio has consulted for US Soccer (paid), US Cycling (unpaid), University of Calgary SHRed Concussions external advisory board (unpaid), medico-legal litigation, and received speaker honorarium and travel reimbursements for talks given. Dr. Broglio is also a co-author of “Biomechanics of Injury (3rd edition)” and has a patent pending on “Brain Metabolism Monitoring Through CCO Measurements Using All-Fiber-Integrated Super-Continuum Source” (U.S. Application No. 17/164,490). Lastly, Dr. Broglio is on the and is/was on the editorial boards (all unpaid) for Journal of Athletic Training (2015 to present), Concussion (2014 to present), Athletic Training & Sports Health Care (2008 to present), and British Journal of Sports Medicine (2008 to 2019).

Informed consent

All study procedures were reviewed and approved by the University of Michigan IRB, the US Army Medical Research and Materiel Command Human Research Protection Office (HRPO), as well the local IRB at each of the performance sites. Participants provided written informed consent prior to participation.

Research involving human participants

The study was performed in accordance with the standards of ethics outlined in the Declaration of Helsinki.

Additional information

Funding

This study was made possible, in part, with support from the Grand Alliance Concussion Assessment, Research, and Education Consortium, funded by the National Collegiate Athletic Association and the Department of Defense. The US Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014, USA is the awarding and administering acquisition office. This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs through the Psychological Health and Traumatic Brain Injury Program under Award no. W81XWH-14-2-0151. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense (Defense Health Program funds).