Explainable machine learning prediction of ICU mortality

Background: There is a variety of mortality prediction models for patients in intensive care units (ICU) to guide appropriate clinical management. Advances in machine learning methodologies typically employ classifiers such as Neural Network and Random Forest which are often regarded by healthcare p...

Full description

Bibliographic Details
Main Authors: Alvin Har Teck Chia, May Sze Khoo, Andy Zhengyi Lim, Kian Eng Ong, Yixuan Sun, Binh P. Nguyen, Matthew Chin Heng Chua, Junxiong Pang
Format: Article
Language:English
Published: Elsevier 2021-01-01
Series:Informatics in Medicine Unlocked
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2352914821001593
_version_ 1819116575928614912
author Alvin Har Teck Chia
May Sze Khoo
Andy Zhengyi Lim
Kian Eng Ong
Yixuan Sun
Binh P. Nguyen
Matthew Chin Heng Chua
Junxiong Pang
author_facet Alvin Har Teck Chia
May Sze Khoo
Andy Zhengyi Lim
Kian Eng Ong
Yixuan Sun
Binh P. Nguyen
Matthew Chin Heng Chua
Junxiong Pang
author_sort Alvin Har Teck Chia
collection DOAJ
description Background: There is a variety of mortality prediction models for patients in intensive care units (ICU) to guide appropriate clinical management. Advances in machine learning methodologies typically employ classifiers such as Neural Network and Random Forest which are often regarded by healthcare professionals as black boxes. These models often do not provide clear links between the input model features and output clinical event. We investigate whether features identified by Cox-Proportional Hazards (CPH) model can be used for ICU mortality prediction. Methods: We employ the PhysioNet Challenge 2012 dataset, a subset of MIMIC-II Clinical Database data of ICU patients admitted to Boston's Beth Israel Deaconess Medical Center from 2001 to 2008. The dataset is split into train set A, test set B and unseen set C, with 4000 patients each. Python is the programming language used alongside scikit-learn, and lifelines packages. Besides white-box feature selection methods (logistic regression and decision tree), we also explore using Cox-Proportional Hazards model for feature selection. We then trained the machine learning model using classifiers such as logistic regression and variants of decision tree. Extreme gradient boosted trees models performed better than other classifiers. The model is validated using 5-fold cross-validation and evaluated against unseen set C. The model performance is assessed using area under the precision-recall curve (AUC-PR) as the main metric. Findings: The data of about 12,000 patients is used, providing a high degree of generalizability. The number of statistically significant features identified by CPH (n = 16) is significantly smaller than logistic regression (n = 36), decision tree (n = 26) and all features (n = 42). With only 16 features used, the model achieves a performance of AUC-PR 0·438 on test set B, which is close to decision tree (AUC-PR 0·442) and logistic regression (AUC-PR 0·446) and all features (AUC-PR 0·446). Interpretation: The significantly fewer features identified by CPH allows the building of a model that is easily interpretable by clinicians whilst still achieving comparable results to other models. This finding allows clinicians to use CPH as an alternative method to determine and act on features that need to be closely monitored for ICU patients.
first_indexed 2024-12-22T05:19:16Z
format Article
id doaj.art-1ba0b64dabb743b9a7298a3078b5caa3
institution Directory Open Access Journal
issn 2352-9148
language English
last_indexed 2024-12-22T05:19:16Z
publishDate 2021-01-01
publisher Elsevier
record_format Article
series Informatics in Medicine Unlocked
spelling doaj.art-1ba0b64dabb743b9a7298a3078b5caa32022-12-21T18:37:46ZengElsevierInformatics in Medicine Unlocked2352-91482021-01-0125100674Explainable machine learning prediction of ICU mortalityAlvin Har Teck Chia0May Sze Khoo1Andy Zhengyi Lim2Kian Eng Ong3Yixuan Sun4Binh P. Nguyen5Matthew Chin Heng Chua6Junxiong Pang7Institute of Systems Science, National University of Singapore, SingaporeInstitute of Systems Science, National University of Singapore, SingaporeInstitute of Systems Science, National University of Singapore, SingaporeInstitute of Systems Science, National University of Singapore, SingaporeInstitute of Systems Science, National University of Singapore, SingaporeSchool of Mathematics and Statistics, Victoria University of Wellington, New Zealand; Corresponding author.Institute of Systems Science, National University of Singapore, Singapore; Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore; Centre for Infectious Disease Epidemiology and Research, Singapore; Corresponding author. Institute of Systems Science, National University of Singapore, Singapore.Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore; Centre for Infectious Disease Epidemiology and Research, Singapore; Corresponding author. Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.Background: There is a variety of mortality prediction models for patients in intensive care units (ICU) to guide appropriate clinical management. Advances in machine learning methodologies typically employ classifiers such as Neural Network and Random Forest which are often regarded by healthcare professionals as black boxes. These models often do not provide clear links between the input model features and output clinical event. We investigate whether features identified by Cox-Proportional Hazards (CPH) model can be used for ICU mortality prediction. Methods: We employ the PhysioNet Challenge 2012 dataset, a subset of MIMIC-II Clinical Database data of ICU patients admitted to Boston's Beth Israel Deaconess Medical Center from 2001 to 2008. The dataset is split into train set A, test set B and unseen set C, with 4000 patients each. Python is the programming language used alongside scikit-learn, and lifelines packages. Besides white-box feature selection methods (logistic regression and decision tree), we also explore using Cox-Proportional Hazards model for feature selection. We then trained the machine learning model using classifiers such as logistic regression and variants of decision tree. Extreme gradient boosted trees models performed better than other classifiers. The model is validated using 5-fold cross-validation and evaluated against unseen set C. The model performance is assessed using area under the precision-recall curve (AUC-PR) as the main metric. Findings: The data of about 12,000 patients is used, providing a high degree of generalizability. The number of statistically significant features identified by CPH (n = 16) is significantly smaller than logistic regression (n = 36), decision tree (n = 26) and all features (n = 42). With only 16 features used, the model achieves a performance of AUC-PR 0·438 on test set B, which is close to decision tree (AUC-PR 0·442) and logistic regression (AUC-PR 0·446) and all features (AUC-PR 0·446). Interpretation: The significantly fewer features identified by CPH allows the building of a model that is easily interpretable by clinicians whilst still achieving comparable results to other models. This finding allows clinicians to use CPH as an alternative method to determine and act on features that need to be closely monitored for ICU patients.http://www.sciencedirect.com/science/article/pii/S2352914821001593Mortality predictionExplainable machine learningICUCox-proportional hazardsFeature selection
spellingShingle Alvin Har Teck Chia
May Sze Khoo
Andy Zhengyi Lim
Kian Eng Ong
Yixuan Sun
Binh P. Nguyen
Matthew Chin Heng Chua
Junxiong Pang
Explainable machine learning prediction of ICU mortality
Informatics in Medicine Unlocked
Mortality prediction
Explainable machine learning
ICU
Cox-proportional hazards
Feature selection
title Explainable machine learning prediction of ICU mortality
title_full Explainable machine learning prediction of ICU mortality
title_fullStr Explainable machine learning prediction of ICU mortality
title_full_unstemmed Explainable machine learning prediction of ICU mortality
title_short Explainable machine learning prediction of ICU mortality
title_sort explainable machine learning prediction of icu mortality
topic Mortality prediction
Explainable machine learning
ICU
Cox-proportional hazards
Feature selection
url http://www.sciencedirect.com/science/article/pii/S2352914821001593
work_keys_str_mv AT alvinharteckchia explainablemachinelearningpredictionoficumortality
AT mayszekhoo explainablemachinelearningpredictionoficumortality
AT andyzhengyilim explainablemachinelearningpredictionoficumortality
AT kianengong explainablemachinelearningpredictionoficumortality
AT yixuansun explainablemachinelearningpredictionoficumortality
AT binhpnguyen explainablemachinelearningpredictionoficumortality
AT matthewchinhengchua explainablemachinelearningpredictionoficumortality
AT junxiongpang explainablemachinelearningpredictionoficumortality