Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Oct 9.
doi: 10.1097/HTR.0000000000001125. Online ahead of print.

Concussion Classification in a Multicenter Patient Cohort: The Updated ACRM Diagnostic Criteria and Concordance With Physician Impression of Injury

Affiliations

Concussion Classification in a Multicenter Patient Cohort: The Updated ACRM Diagnostic Criteria and Concordance With Physician Impression of Injury

Andrew B Dodd et al. J Head Trauma Rehabil. .

Abstract

Objective: The American Congress of Rehabilitation Medicine (ACRM) substantially revised its diagnostic criteria for mild traumatic brain injury (mTBI) in 2023, encompassing acute symptoms and positive clinical and laboratory examinations, in addition to immediate signs of injury. This study aimed to apply these criteria to a large, diverse cohort and compare the diagnostic determination to physician impression of injury.

Setting: A network of 3 concussion specialty clinics in Ontario, Canada.

Participants: A total of 1447 patients (61.0% female; median age = 26 years [IQR: 15-42 years, range: 3-87 years]; days post-injury (median: 23 IQR: [13-47, 0-349]) completed initial evaluations between June 28, 2024 and June 18, 2025.

Design: Prospective observational study.

Main measures: Occurrence rates were calculated, and binary/ordinal logistic regressions were applied to determine if individual criterion endorsement or diagnostic outcome ("Definite," "Suspected," and "No mTBI") was associated with age, sex, symptoms at clinical presentation, or days post-injury. Additionally, concordance with physician impression was assessed similarly.

Results: Criteria for signs, symptoms, and clinical examinations were all more likely to be endorsed with increasing symptom severity at presentation, as was an ACRM diagnostic outcome of definite mTBI. Shorter time post-injury was associated with positive clinical/laboratory examinations and the presence of confounding factors, in addition to a definite diagnostic outcome. A total of 18.4% of cases were classified less definitively as mTBI by physician impression than by the updated ACRM diagnosis, with physicians tending toward underdiagnosis, particularly in patients reporting lower current symptom severity.

Conclusion: Use of the ACRM criteria clinically to determine if an injury qualifies as mTBI may be less susceptible to bias from ongoing symptom reporting than the physician impression of the injury.

Keywords: ACRM; concussion; diagnostic criteria; mild traumatic brain injury; physician impression.

PubMed Disclaimer

References

    1. Kay T, Harrington DE, Adams R, et al. Mild Traumatic Brain Injury Committee of the Head Injury Interdisciplinary Special Interest Group of the American Congress of Rehabilitation Medicine. Definition of mild traumatic brain injury. J Head Trauma Rehabil 1993;8(3):86-87.
    1. Patricios JS, Schneider KJ, Dvorak J, et al. Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport–Amsterdam 2022. Br J Sports Med 2023;57(11):695–711.
    1. Management of Concussion/mTBI Working Group. VA/DoD Clinical Practice Guideline for Management of Concussion/Mild Traumatic Brain Injury. J Rehabil Res Dev. 2009;46(6):CP1-68.
    1. West TA, Marion DW. Current recommendations for the diagnosis and treatment of concussion in sport: a comparison of three new guidelines. J Neurotrauma 2014;31(2):159–168.
    1. Borg J, Holm L, Cassidy JD, et al. Diagnostic procedures in mild traumatic brain injury: results of the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury. J Rehabil Med 2004;43(Suppl):61–75.

LinkOut - more resources