eprintid: 10203130 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/20/31/30 datestamp: 2025-01-10 09:04:16 lastmod: 2025-01-10 09:04:16 status_changed: 2025-01-10 09:04:16 type: article metadata_visibility: show sword_depositor: 699 creators_name: Arina, Pietro creators_name: Ferrari, Davide creators_name: Tetlow, Nicholas creators_name: Dewar, Amy creators_name: Stephens, Robert creators_name: Martin, Daniel creators_name: Moonesinghe, Ramani creators_name: Curcin, Vasa creators_name: Singer, Mervyn creators_name: Whittle, John creators_name: Mazomenos, Evangelos B title: Mortality prediction after major surgery in a mixed population through machine learning: a multi-objective symbolic regression approach ispublished: inpress divisions: UCL divisions: B02 divisions: C10 divisions: D17 keywords: cardiopulmonary exercise testing, machine learning, mortality, multi‐objective symbolic regression note: © 2025 The Author(s). Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. abstract: INTRODUCTION: Understanding 1-year mortality following major surgery offers valuable insights into patient outcomes and the quality of peri-operative care. Few models exist that predict 1-year mortality accurately. This study aimed to develop a predictive model for 1-year mortality in patients undergoing complex non-cardiac surgery using a novel machine-learning technique called multi-objective symbolic regression. METHODS: A single-institution database of patients undergoing major elective surgery with previous cardiopulmonary exercise testing was divided into three datasets: pre-operative clinical data; cardiorespiratory and physiological data; and combined. A multi-objective symbolic regression model was developed and compared against existing models. Model performance was evaluated using the F1 score. Shapley additive explanations analysis was used to identify the major contributors to model performance. RESULTS: From 2145 patients in the database, 1190 were included, with 952 in the training dataset and 238 in the test dataset. Median (IQR [range]) age was 71 (61-79 [45-89]) years and 825 (69%) were male. The multi-objective symbolic regression model demonstrated robust consistency with an F1 score of 0.712. Shapley additive explanations analysis indicated that ventilatory equivalents for carbon dioxide, oxygen at peak exercise and BMI influenced model performance most significantly, surpassing surgery type and named comorbidities. DISCUSSION: This study confirms the feasibility of developing a multi-objective symbolic regression-based model for predicting 1-year postoperative mortality in a mixed non-cardiac surgical population. The model's strong performance underscores the critical role of physiological data, particularly cardiorespiratory fitness, in surgical risk assessment and emphasises the importance of pre-operative optimisation to identify and manage high-risk patients. The multi-objective symbolic regression model demonstrated high sensitivity and a good F1 score, highlighting its potential as an effective tool for peri-operative risk prediction. date: 2025-01-08 date_type: published publisher: Wiley official_url: https://doi.org/10.1111/anae.16538 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2351720 doi: 10.1111/anae.16538 lyricists_name: Arina, Pietro lyricists_id: PARIN35 actors_name: Arina, Pietro actors_id: PARIN35 actors_role: owner funding_acknowledgements: 203145Z/16/Z [Wellcome Trust]; NS/A000050/1 [Wellcome Trust]; [Cleveland Clinic London Hospital]; [Cleveland Clinic Philanthropy]; [King's College London]; [University College London Hospitals National Institute of Health Research Biomedical Research Centre]; [International Anaesthesia Research Society Mentored Research Grant] full_text_status: public publication: Anaesthesia event_location: England issn: 0003-2409 citation: Arina, Pietro; Ferrari, Davide; Tetlow, Nicholas; Dewar, Amy; Stephens, Robert; Martin, Daniel; Moonesinghe, Ramani; ... Mazomenos, Evangelos B; + view all <#> Arina, Pietro; Ferrari, Davide; Tetlow, Nicholas; Dewar, Amy; Stephens, Robert; Martin, Daniel; Moonesinghe, Ramani; Curcin, Vasa; Singer, Mervyn; Whittle, John; Mazomenos, Evangelos B; - view fewer <#> (2025) Mortality prediction after major surgery in a mixed population through machine learning: a multi-objective symbolic regression approach. Anaesthesia 10.1111/anae.16538 <https://doi.org/10.1111/anae.16538>. (In press). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10203130/1/Anaesthesia%20-%202025%20-%20Arina%20-%20Mortality%20prediction%20after%20major%20surgery%20in%20a%20mixed%20population%20through%20machine%20learning%20%20a.pdf