Prediction of outcome after aneurysmal subarachnoid haemorrhage using data from patient admission
The pathogenesis leading to poor functional outcome after aneurysmal subarachnoid haemorrhage (aSAH) is multifactorial and not fully understood. We evaluated a machine learning approach based on easily determinable clinical and CT perfusion (CTP) features in the course of patient admission to predict the functional outcome 6 months after ictus.
Out of 630 consecutive subarachnoid haemorrhage patients (2008–2015), 147 (mean age 54.3, 66.7% women) were retrospectively included (Inclusion: aSAH, admission within 24 h of ictus, CTP within 24 h of admission, documented modified Rankin scale (mRS) grades after 6 months. Exclusion: occlusive therapy before first CTP, previous aSAH, CTP not evaluable). A random forests model with conditional inference trees was optimised and trained on sex, age, World Federation of Neurosurgical Societies (WFNS) and modified Fisher grades, aneurysm in anterior vs. posterior circulation, early external ventricular drainage (EVD), as well as MTT and Tmax maximum, mean, standard deviation (SD), range, 75th quartile and interquartile range to predict dichotomised mRS (≤ 2; > 2). Performance was assessed using the balanced accuracy over the training and validation folds using 20 repeats of 10-fold cross-validation.
In the final model, using 200 trees and the synthetic minority oversampling technique, median balanced accuracy was 84.4% (SD 0.7) over the training folds and 70.9% (SD 1.2) over the validation folds. The five most important features were the modified Fisher grade, age, MTT range, WFNS and early EVD.
A random forests model trained on easily determinable features in the course of patient admission can predict the functional outcome 6 months after aSAH with considerable accuracy.
• Features determinable in the course of admission of a patient with aneurysmal subarachnoid haemorrhage (aSAH) can predict the functional outcome 6 months after the occurrence of aSAH.
• The top five predictive features were the modified Fisher grade, age, the mean transit time (MTT) range from computed tomography perfusion (CTP), the WFNS grade and the early necessity for an external ventricular drainage (EVD).
• The range between the minimum and the maximum MTT may prove to be a valuable biomarker for detrimental functional outcome.
KeywordsSubarachnoid haemorrhage Aneurysm Multidetector computed tomography Critical care outcomes Machine learning
Abbreviations and acronyms
Aneurysmal subarachnoid haemorrhage
Delayed cerebral ischaemia
External ventricular drainage
Glasgow coma scale
Modified Rankin scale
Mean transit time
Synthetic minority oversampling technique
World Federation of Neurosurgical Societies
Editing assistance of an earlier version of the manuscript: Bonnie Hami, M.A. (Cleveland, OH, USA).
The authors state that this work has not received any funding.
Compliance with ethical standards
The scientific guarantor of this publication is Christian Rubbert.
Conflict of interest
The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.
Statistics and biometry
One of the authors has significant statistical expertise.
Written informed consent was waived by the institutional review board.
Institutional review board approval was obtained.
• cross-sectional study
• performed at one institution
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