<?xml version="1.0" encoding="UTF-8"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-10-18T23:15:20Z</responseDate><request verb="GetRecord" identifier="oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/10083" metadataPrefix="oai_dc">https://ebyu-rdlopen.rawdatalibrary.net/oai/request</request><GetRecord><record><header><identifier>oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/10083</identifier><datestamp>2026-10-18T20:41:14Z</datestamp><setSpec>openaire</setSpec><setSpec>driver</setSpec><setSpec>com_ebyu_10000</setSpec><setSpec>col_ebyu_10001</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"><dc:title>A Novel Biomarker-Based Decision Support System for Pediatric Appendicitis Diagnosis: A Comparative Study of Ensemble Models Algorithms</dc:title><dc:creator>Avci, Veli</dc:creator><dc:creator>Huyut, Mehmet Tahir</dc:creator><dc:creator>Velichko, Andrei</dc:creator><dc:creator>Belyaev, Maksim</dc:creator><dc:subject>Appendicitis</dc:subject><dc:subject>Biomarkers</dc:subject><dc:subject>Boosting and bagging based ensemble models</dc:subject><dc:subject>Clinical decision support system (CDDS)</dc:subject><dc:subject>SHAP</dc:subject><dc:subject>SMOTE</dc:subject><dc:subject>biological marker</dc:subject><dc:subject>C reactive protein</dc:subject><dc:subject>abdominal pain</dc:subject><dc:subject>adolescent</dc:subject><dc:subject>adult</dc:subject><dc:subject>arithmetic</dc:subject><dc:subject>Article</dc:subject><dc:subject>child</dc:subject><dc:subject>clinical decision support system</dc:subject><dc:subject>cohort analysis</dc:subject><dc:subject>comparative study</dc:subject><dc:subject>correlation coefficient</dc:subject><dc:subject>cross validation</dc:subject><dc:subject>decision tree</dc:subject><dc:subject>diagnostic accuracy</dc:subject><dc:subject>diagnostic test accuracy study</dc:subject><dc:subject>electronic health record</dc:subject><dc:subject>emergency ward</dc:subject><dc:subject>ensemble learning</dc:subject><dc:subject>false negative result</dc:subject><dc:subject>female</dc:subject><dc:subject>histopathology</dc:subject><dc:subject>human</dc:subject><dc:subject>infant</dc:subject><dc:description>Introduction: Acute appendicitis is the commonest cause of surgical abdominal pain, yet diagnosis in children remains challenging; delays increase the risk of perforation, peritonitis and sepsis. We sought to develop a rapid, inexpensive and interpretable clinical-decision support system (CDSS) that leverages routine blood tests (RBT) to assist early paediatric triage. Materials and Methods: In this retrospective single-centre study (January 2020–December 2024) we analysed 275 emergency-department encounters for abdominal pain (75 histology-confirmed appendicitis, 200 controls). The six-stage pipeline comprised (1) cohort selection; (2) exploratory logistic-regression screening of RBT variables; (3) training of Random Forest, Gradient Boosting and LightGBM ensembles (with/without SMOTE) under 10 × 10 stratified cross-validation; (4) SHAP-based feature interpretation; (5) exhaustive generation of every two- and three-parameter arithmetic biomarker from seven RBT features; and (6) derivation of probability-threshold curves and a three-zone rule tree for the top biomarker. Performance was reported with accuracy (ACC), Matthews correlation coefficient (MCC), AUC-ROC, sensitivity, specificity, F1-Score PPV and NPV. Results: Logistic regression and SHAP confirmed CRP, WBC and neutrophil count as strong positive predictors, whereas MPV and PDW were protective; PLT remained non-informative. All three ensemble classifiers surpassed 97% accuracy, 98% AUC-ROC and 0.93 MCC, with no gain from SMOTE. An extensive formula search, the best two-parameter marker was Neutrophil ÷ PDW (MCC = 0.73, specificity 95%). Its ensemble curve crosses P = 0.5 five times; practical cut-offs of &lt; 0.633 (strongly indicate healthy) and &gt; 0.794 (strongly indicate appendicitis) retain high NPV (∼91%) and PPV (∼86%). Among triple formulas that do not rely on PLT, the leading biomarker was CRP+WBC+Neutrophil (MCC = 0.85, PPV 92%, NPV 95%). The ensemble curve intersects at P = 0.5 at three points; values &gt;27 strongly predict appendicitis, &lt;23 indicates a healthy state, and values 23–27 leave a small uncertain band. A rule-based CDSS built on these two biomarkers correctly classified all controls (specificity 100%), sensitivity 95%, achieved 91% overall accuracy, and offers interpretable, electronic health records (EHRs)-ready cut-offs for paediatric appendicitis triage. Conclusion: Routine haematology-biochemistry data, interpreted through ensemble learning and engineered biomarkers, can deliver fast, transparent and highly accurate support for paediatric appendicitis triage. Given its zero false-positive rate, the proposed CDSS is best suited to in-hospital monitoring, where minimising false negatives is critical. Prospective multi-centre validation is warranted. © 2025 AGBM</dc:description><dc:publisher>Elsevier Masson s.r.l.</dc:publisher><dc:date>2026</dc:date><dc:type>Article</dc:type><dc:identifier>https://rdlopen.rawdatalibrary.net/r/ebyu/10083</dc:identifier><dc:identifier>https://doi.org/10.1016/j.irbm.2025.100921</dc:identifier><dc:identifier>1959-0318</dc:identifier><dc:language>en</dc:language><dc:relation>IRBM</dc:relation><dc:rights>info:eu-repo/semantics/openAccess</dc:rights><dc:type>info:eu-repo/semantics/article</dc:type><dc:identifier>https://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/10083</dc:identifier></oai_dc:dc></metadata></record></GetRecord></OAI-PMH>