Cardiac surgery risk prediction using ensemble machine learning to incorporate legacy risk scores: A benchmarking study

Bibliographic Details
Title: Cardiac surgery risk prediction using ensemble machine learning to incorporate legacy risk scores: A benchmarking study
Authors: Tim Dong, Shubhra Sinha, Ben Zhai, Daniel P Fudulu, Jeremy Chan, Pradeep Narayan, Andy Judge, Massimo Caputo, Arnaldo Dimagli, Umberto Benedetto, Gianni D Angelini
Source: Digital Health, Vol 9 (2023)
Publisher Information: SAGE Publishing, 2023.
Publication Year: 2023
Collection: LCC:Computer applications to medicine. Medical informatics
Subject Terms: Computer applications to medicine. Medical informatics, R858-859.7
More Details: Objective The introduction of new clinical risk scores (e.g. European System for Cardiac Operative Risk Evaluation (EuroSCORE) II) superseding original scores (e.g. EuroSCORE I) with different variable sets typically result in disparate datasets due to high levels of missingness for new score variables prior to time of adoption. Little is known about the use of ensemble learning to incorporate disparate data from legacy scores. We tested the hypothesised that Homogenenous and Heterogeneous Machine Learning (ML) ensembles will have better performance than ensembles of Dynamic Model Averaging (DMA) for combining knowledge from EuroSCORE I legacy data with EuroSCORE II data to predict cardiac surgery risk. Methods Using the National Adult Cardiac Surgery Audit dataset, we trained 12 different base learner models, based on two different variable sets from either EuroSCORE I (LogES) or EuroScore II (ES II), partitioned by the time of score adoption (1996–2016 or 2012–2016) and evaluated on holdout set (2017–2019). These base learner models were ensembled using nine different combinations of six ML algorithms to produce homogeneous or heterogeneous ensembles. Performance was assessed using a consensus metric. Results Xgboost homogenous ensemble (HE) was the highest performing model (clinical effectiveness metric (CEM) 0.725) with area under the curve (AUC) (0.8327; 95% confidence interval (CI) 0.8323–0.8329) followed by Random Forest HE (CEM 0.723; AUC 0.8325; 95%CI 0.8320–0.8326). Across different heterogenous ensembles, significantly better performance was obtained by combining siloed datasets across time (CEM 0.720) than building ensembles of either 1996–2011 ( t -test adjusted, p = 1.67×10 −6 ) or 2012–2019 ( t -test adjusted, p = 1.35×10 −193 ) datasets alone. Conclusions Both homogenous and heterogenous ML ensembles performed significantly better than DMA ensemble of Bayesian Update models. Time-dependent ensemble combination of variables, having differing qualities according to time of score adoption, enabled previously siloed data to be combined, leading to increased power, clinical interpretability of variables and usage of data.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2055-2076
20552076
Relation: https://doaj.org/toc/2055-2076
DOI: 10.1177/20552076231187605
Access URL: https://doaj.org/article/f669890babf046c78389400978acba6b
Accession Number: edsdoj.f669890babf046c78389400978acba6b
Database: Directory of Open Access Journals
More Details
ISSN:20552076
DOI:10.1177/20552076231187605
Published in:Digital Health
Language:English