====== Corticosteroid Randomization After Signification Head injury (CRASH) ======

http://www.crash.lshtm.ac.uk/Risk%20calculator/index.html

see also [[IMPACT prognostic calculator]].

[[Prognostic model]]s that were developed by the International Mission on Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury ([[IMPACT]]) study group and the [[Corticosteroid]] Randomization After Signification Head injury ([[CRASH]]) collaborators are the most commonly used prognostic models for [[outcome]] after [[traumatic brain injury]] (TBI). Although they have been considered to be useful tools in clinical practice
((Roozenbeek B, Lingsma HF, Lecky FE, Lu J, Weir J, Butcher I, McHugh GS, Murray
GD, Perel P, Maas AI, Steyerberg EW; 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
May;40(5):1609-17. doi: 10.1097/CCM.0b013e31824519ce. PubMed PMID: 22511138;
PubMed Central PMCID: PMC3335746.
))
, a continuous process of [[external validity]] in recent cohorts of different populations is necessary. 
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The objective of a study was to determine the [[external validity]] and compare the IMPACT and CRASH-refitted models for prediction of outcomes after moderate or [[severe traumatic brain injury]] in a non-selected 1301-patient Spanish cohort. They studied discrimination, calibration, and overall fit as external validation measures. Excellent discrimination was indicated (area under the curve [AUC] 0.78-0.87) by the higher values in the validation than in the development sample for both models and outcomes. Calibration revealed that IMPACT models, in general, predict lower probabilities of both outcomes (mortality and disability). In contrast, CRASH-refitted models provided higher predicted probabilities than those observed. Castaño-Leon et al., can conclude that both models demonstrate an adequate performance in the representative traumatic brain Mediterranean population. Therefore, these models can be sensibly applied in the clinical practice so long as their limitations are observed during individual outcome prediction
((Castaño-Leon AM, Lora D, Munarriz PM, Cepeda S, Paredes I, de la Cruz J, Gómez
Lopez PA, Lagares A. Predicting Outcomes after Severe and Moderate Traumatic
Brain Injury: An External Validation of Impact and Crash Prognostic Models in a
Large Spanish Cohort. J Neurotrauma. 2016 Sep 1;33(17):1598-606. doi:
10.1089/neu.2015.4182. Epub 2016 Mar 16. PubMed PMID: 26982260.
)).
----
Han et al., used a cohort of 300 patients with severe TBI (Glasgow Coma Score [GCS] ≤8) consecutively admitted to the National Neuroscience Institute (NNI), Singapore, between February 2006 and December 2009. The CRASH models (base and CT) predict 14 day mortality and 6 month unfavorable outcome. The IMPACT models (core, extended, and laboratory) estimate 6 month mortality and unfavorable outcome. Validation was based on measures of discrimination and calibration. Discrimination was assessed using the area under the receiving operating characteristic curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (H-L) goodness-of-fit test and Cox calibration regression analysis. In the NNI database, the overall observed 14 day mortality was 47.7%, and the observed 6 month unfavorable outcome was 71.0%. The CRASH base model and all three IMPACT models gave an underestimate of the observed values in this cohort when used to predict outcome. Using the CRASH CT model, the predicted 14 day mortality of 46.6% approximated the observed outcome, whereas the predicted 6 month unfavorable outcome was an overestimate at 74.8%. Overall, both the CRASH and IMPACT models showed good discrimination, with AUCs ranging from 0.80 to 0.89, and good overall calibration. They conclude that both the CRASH and IMPACT models satisfactorily predicted outcome in the patients with severe TBI
((Han J, King NK, Neilson SJ, Gandhi MP, Ng I. External validation of the CRASH 
and IMPACT prognostic models in severe traumatic brain injury. J Neurotrauma.
2014 Jul 1;31(13):1146-52. doi: 10.1089/neu.2013.3003. Epub 2014 May 12. PubMed
PMID: 24568201.
)).