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. 2023 Mar 1;4(1):118-123.
doi: 10.1089/neur.2022.0082. eCollection 2023.

Performance of CRASH and IMPACT Prognostic Models for Traumatic Brain Injury at 12 and 24 Months Post-Injury

Shawn R Eagle  1 , Enyinna Nwachuku  2 , Jonathan Elmer  3 , Hansen Deng  1 , David O Okonkwo  1 , Matthew Pease  4
Affiliations

Performance of CRASH and IMPACT Prognostic Models for Traumatic Brain Injury at 12 and 24 Months Post-Injury

Shawn R Eagle et al. Neurotrauma Rep. .

Abstract

The Corticoid Randomization after Significant Head Injury (CRASH) and International Mission for Prognosis and Analysis of Clinical Trials (IMPACT) prognostic models are the most reported prognostic models for traumatic brain injury (TBI) in the scientific literature. However, these models were developed and validated to predict 6-month unfavorable outcome and mortality, and growing evidence supports continuous improvements in functional outcome after severe TBI up to 2 years post-injury. The purpose of this study was to evaluate CRASH and IMPACT model performance beyond 6 months post-injury to include 12 and 24 months post-injury. Discriminative validity remained consistent over time and comparable to earlier recovery time points (area under the curve = 0.77-0.83). Both models had poor fit for unfavorable outcomes, explaining less than one quarter of the variation in outcomes for severe TBI patients. The CRASH model had significant values for the Hosmer-Lemeshow test at 12 and 24 months, indicating poor model fit past the previous validation point. There is concern in the scientific literature that TBI prognostic models are being used by neurotrauma clinicians to support clinical decision making despite the goal of the models' development being to support research study design. The results of this study indicate that the CRASH and IMPACT models should not be used in routine clinical practice because of poor model fit that worsens over time and the large, unexplained variance in outcomes.

Keywords: adult brain injury; models of injury; traumatic brain injury.

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Conflict of interest statement

No competing financial interests exist.

Figures

FIG. 1.
FIG. 1.
Receiver operating characteristic area under the curve outputs for CRASH and IMPACT models to predict unfavorable outcomes (GOSE = 1–4) at 12 months (A) and 24 months (B). Receiver operating characteristic area under the curve outputs for CRASH and IMPACT models to predict mortality in severe TBI patients at 12 months (C) and 24 months (D). GOSE, Glasgow Outcome Score-Extended; TBI, traumatic brain injury.
See this image and copyright information in PMC

References

    1. Nelson LD, Temkin NR, Dikmen S, et al. Recovery after mild traumatic brain injury in patients presenting to US Level I trauma centers: a Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Study. JAMA Neurol 2019;76(9):1049–1059; doi: 10.1001/jamaneurol.2019.1313 - DOI - PMC - PubMed
    1. MRC CRASH Trial Collaborators. Predicting outcome after traumatic brain injury: practical prognostic models based on large cohort of international patients. BMJ 2008;336(7641):425–429; doi: 10.1136/bmj.39461.643438.25 - DOI - PMC - PubMed
    1. Roozenbeek B, Lingsma HF, Lecky FE, et al. ; International Mission on Prognosis Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) Study Group; Corticosteroid Randomisation After Significant Head Injury (CRASH) Trial Collaborators; Trauma Audit and Research Network (TARN). Prediction of outcome after moderate and severe traumatic brain injury: external validation of the International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) and Corticoid Randomisation After Significant Head injury (CRASH) prognostic models. Crit Care Med 2012;40(5):1609–1617; doi: 10.1097/CCM.0b013e31824519ce - DOI - PMC - PubMed
    1. Dijkland SA, Foks KA, Polinder S, et al. Prognosis in moderate and severe traumatic brain injury: a systematic review of contemporary models and validation studies. J Neurotrauma 2020;37(1):1–13; doi: 10.1089/neu.2019.6401 - DOI - PubMed
    1. Panczykowski DM, Puccio AM, Scruggs BJ, et al. Prospective independent validation of IMPACT modeling as a prognostic tool in severe traumatic brain injury. J Neurotrauma 2012;29(1):47–52; doi: 10.1089/neu.2010.1482 - DOI - PubMed

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