{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T03:18:48Z","timestamp":1783567128854,"version":"3.55.0"},"reference-count":39,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T00:00:00Z","timestamp":1753833600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Barri Casanovas Private Foundation Scholarship","award":["FBC02\/2023"],"award-info":[{"award-number":["FBC02\/2023"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: The SARS-CoV-2 and influenza A (H1N1)pdm09 pandemics have resulted in high numbers of ICU admissions, with high mortality. Identifying risk factors for ICU mortality at the time of admission can help optimize clinical decision making. However, the risk factors identified may differ, depending on the type of analysis used. Our aim is to compare the risk factors and performance of a linear model (multivariable logistic regression, GLM) with a non-linear model (random forest, RF) in a large national cohort. Methods: A retrospective analysis was performed on a multicenter database including 8902 critically ill patients with influenza A (H1N1)pdm09 or COVID-19 admitted to 184 Spanish ICUs. Demographic, clinical, laboratory, and microbiological data from the first 24 h were used. Prediction models were built using GLM and RF. The performance of the GLM was evaluated by area under the ROC curve (AUC), precision, sensitivity, and specificity, while the RF by out-of-bag (OOB) error and accuracy. In addition, in the RF, the im-portance of the variables in terms of accuracy reduction (AR) and Gini index reduction (GI) was determined. Results: Overall mortality in the ICU was 25.8%. Model performance was similar, with AUC = 76% for GLM, and AUC = 75.6% for RF. GLM identified 17 independent risk factors, while RF identified 19 for AR and 23 for GI. Thirteen variables were found to be important in both models. Laboratory variables such as procalcitonin, white blood cells, lactate, or D-dimer levels were not significant in GLM but were significant in RF. On the contrary, acute kidney injury and the presence of Acinetobacter spp. were important variables in the GLM but not in the RF. Conclusions: Although the performance of linear and non-linear models was similar, different risk factors were determined, depending on the model used. This alerts clinicians to the limitations and usefulness of studies limited to a single type of model.<\/jats:p>","DOI":"10.3390\/jcm14155383","type":"journal-article","created":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T14:29:02Z","timestamp":1753885742000},"page":"5383","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Machine Learning-Based Identification of Risk Factors for ICU Mortality in 8902 Critically Ill Patients with Pandemic Viral Infection"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7361-7835","authenticated-orcid":false,"given":"Elisabeth","family":"Papiol","sequence":"first","affiliation":[{"name":"Intensive Care Department, Vall d\u2019Hebron University Hospital, 08035 Barcelona, Spain"},{"name":"Shock, Organ Dysfunction and Resuscitation Research Group, Vall d\u2019Hebron Research Institute (VHIR), 08035 Barcelona, Spain"},{"name":"Medicine Department, Universitat Aut\u00f2noma de Barcelona, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ricard","family":"Ferrer","sequence":"additional","affiliation":[{"name":"Intensive Care Department, Vall d\u2019Hebron University Hospital, 08035 Barcelona, Spain"},{"name":"Shock, Organ Dysfunction and Resuscitation Research Group, Vall d\u2019Hebron Research Institute (VHIR), 08035 Barcelona, Spain"},{"name":"Medicine Department, Universitat Aut\u00f2noma de Barcelona, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7392-8617","authenticated-orcid":false,"given":"Juan C.","family":"Ruiz-Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"Intensive Care Department, Vall d\u2019Hebron University Hospital, 08035 Barcelona, Spain"},{"name":"Shock, Organ Dysfunction and Resuscitation Research Group, Vall d\u2019Hebron Research Institute (VHIR), 08035 Barcelona, Spain"},{"name":"Medicine Department, Universitat Aut\u00f2noma de Barcelona, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3637-3821","authenticated-orcid":false,"given":"Emili","family":"D\u00edaz","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Parc Tauli, 08208 Sabadell, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6593-5486","authenticated-orcid":false,"given":"Rafael","family":"Zaragoza","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Dr. Peset, 46017 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcio","family":"Borges-Sa","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Son Llatzer, 07198 Palma de Mallorca, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julen","family":"Berrueta","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Universitari Joan XXIII, 43005 Tarragona, Spain"},{"name":"Tarragona Health Data Research Working Group (TheDaR), 43005 Tarragona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0573-7621","authenticated-orcid":false,"given":"Josep","family":"G\u00f3mez","sequence":"additional","affiliation":[{"name":"Technical Secretary Department, Hospital Universitari Joan XXIII, 43005 Tarragona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7652-8379","authenticated-orcid":false,"given":"Mar\u00eda","family":"Bod\u00ed","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Universitari Joan XXIII, 43005 Tarragona, Spain"},{"name":"Medicine Department, Rovira i Virgili University, 43002 Tarragona, Spain"},{"name":"Pere Virgili Health Research Institute, 43005 Tarragona, Spain"},{"name":"Centre for Biomedical Research Network Respiratory Diseases (CIBERES), 43005 Tarragona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susana","family":"Sancho","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Universitario y Polit\u00e9cnico La Fe, 46026 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Borja","family":"Suberviola","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Marques de Valdecilla, 39008 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Trefler","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Universitari Joan XXIII, 43005 Tarragona, Spain"},{"name":"Pere Virgili Health Research Institute, 43005 Tarragona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8828-5984","authenticated-orcid":false,"given":"Alejandro","family":"Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"Critical Care Department, Hospital Universitari Joan XXIII, 43005 Tarragona, Spain"},{"name":"Pere Virgili Health Research Institute, 43005 Tarragona, Spain"},{"name":"Centre for Biomedical Research Network Respiratory Diseases (CIBERES), 43005 Tarragona, Spain"},{"name":"Basic Sciences Department, Rovira I Virgili University, 43201 Tarragona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,30]]},"reference":[{"key":"ref_1","unstructured":"Centers for Disease Control and Prevention (CDC) (2025, April 24). 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