Zeng S, Yusufujiang A, Dang H et al. · Front Neurol
External validation 99%
Abstract
Background And Purpose: Prehospital delay remains a major barrier to timely reperfusion therapy in acute ischemic stroke (AIS). We externally validated eight prediction algorithms and examined whether complex machine-learning models added value beyond logistic regression.
Methods: This retrospective cohort study included consecutive patients with AIS from two hospitals in Kashgar, China (January 2019-December 2024). Hospital 1 (n = 1,377) was the development cohort and Hospital 2 (n = 1,015) the independent validation cohort. Prehospital delay was defined as onset-to-door time >4.5 h. LASSO selection and tuning were restricted to Hospital 1. Sensitivity analyses used all 36 encoded candidate features and repeated all models without SMOTE. Evaluation included discrimination, calibration, post-hoc recalibration, and decision curves.
Results: Delay occurred in 80.9 and 83.2% of the two cohorts. In the prespecified LASSO-plus-SMOTE analysis, XGBoost had the highest validation AUC (0.771; 95% CI, 0.734-0.807), but did not significantly outperform logistic regression (difference, 0.015; 95% CI, -0.003 to 0.034; p = 0.107). Full-feature modeling produced no consistent gain. Omitting SMOTE improved calibration and often discrimination; logistic regression without SMOTE achieved AUC 0.774 and Brier score 0.122, versus 0.756 and 0.180 with SMOTE. The original SMOTE-trained logistic model underestimated absolute risk. Rural residence, non-emergency-channel presentation, referral, and non-ambulance transport were associated with absolute risk differences of 15.8, 21.5, 9.2, and 36.3 percentage points in Hospital 2.
Conclusion: Complex algorithms did not show a clear advantage over logistic regression. Because several predictors are available only after arrival, the framework is intended for retrospective health-system profiling and quality-improvement planning, not individual pre-arrival prediction. Universal interventions remain warranted given the high prevalence of delay.
Background: Early distant recurrence within 18 months reflects aggressive tumor biology in Stage III colon cancer. Current anatomical staging often fails to capture this biological heterogeneity.
Objective: To develop and externally validate a simple, pathology-based model for ruling out early distant recurrence within 18 months in Stage III colon cancer.
Design: Retrospective model development with external validation, following current machine-learning prediction-model reporting guidelines.
Settings: Derivation at a tertiary referral center; validation at an independent tertiary institution.
Patients: Three hundred thirty-one patients in the derivation cohort (62 events) and 142 in the external cohort (19 events) who underwent curative-intent colectomy for Stage III colon adenocarcinoma.
Main Outcome Measures: Early distant recurrence within 18 months. Secondary outcomes included disease-free survival and calibration performance.
Results: A 4-variable XGBoost model (American Joint Committee on Cancer substage, lymph node ratio, perineural invasion, and differentiation) achieved a pooled out-of-fold area under the curve of 0.680 in the derivation cohort, comparable to conventional staging (0.625). Sensitivity (77.4%) and negative predictive value (89.8%) exceeded those of conventional staging. On external validation, the model yielded an area under the curve of 0.633 (vs 0.610 for conventional staging) and a negative predictive value of 90.8%, maintaining rule out performance of approximately 90% across both cohorts despite their differing recurrence rates. High-risk patients in the external cohort had worse disease-free survival (hazard ratio 1.83; 95% confidence interval 1.06-3.16). Exploratory subgroup analyses showed directionally consistent but statistically inconclusive results.
Limitations: Retrospective design, limited molecular data, and small numbers of events in the external cohort.
Conclusions: A simple 4-predictor model using routine pathological variables provides consistent rule out performance for early distant recurrence within 18months across 2 independent cohorts. The model offers a practical risk-assessment tool for early postoperative counseling where molecular testing is unavailable. A web-based calculator was developed to support early postoperative risk assessment. See Video Abstract.
Objective: This study aimed to identify factors associated with adenoma recurrence within three years after endoscopic mucosal resection (EMR) and to develop an individualized predictive model.
Methods: Patients undergoing their first EMR for colorectal polyps at the Affiliated Hospital of Xuzhou Medical University (September 2018-May 2025) were retrospectively included and randomly divided into training and testing cohorts (7:3). Patients from the Third Affiliated Hospital of Xuzhou Medical University served as the external validation cohort. Least absolute shrinkage and selection operator (LASSO) regression was used to select predictors. Logistic regression (LR), random forest (RF), support vector machine (SVM), gradient boosting machine (GBM), and extreme gradient boosting (XGBoost) models were constructed. Model performance was assessed using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). SHapley additive explanations (SHAP) values were applied to interpret variable contributions, and an online prediction tool was developed.
Results: A total of 1,454 patients were enrolled, of whom 731 developed adenoma recurrence within three years. LASSO identified ten predictors: infection of Helicobacter pylori (H. pylori), the number of adenomas, age, triglyceride level, body mass index (BMI), diarrhea, smoking history, family history, adenoma size, and fecal occult blood positivity. GBM achieved the highest mean AUC in repeated cross-validation (0.813) and maintained robust discrimination in the testing (AUC = 0.818) and external validation cohorts (AUC = 0.775), with good calibration and clinical utility. SHAP analysis identified H. pylori infection, adenoma number, and age as the leading contributors to model predictions.
Conclusion: GBM demonstrated favorable discrimination, calibration, and clinical utility across validation cohorts, supporting its use for individualized risk stratification. The resulting online calculator may further facilitate risk assessment and inform follow-up strategies in clinical practice.
Zhou X, Chen Y, Qian K et al. · Front Public Health
Prospective 98%
Abstract
Objective: To develop and temporally prospectively validate an interpretable model for identifying concurrent depressive symptoms in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).
Methods: This study was conducted in two stages: retrospective development and prospective validation. In the development stage, 304 AECOPD patients admitted to the Fourth Affiliated Hospital of Anhui Medical University from September 2023 to February 2025 were retrospectively enrolled and randomly divided into a training set (n = 214) and an internal validation set (n = 90) at a 7:3 ratio. Candidate predictors were screened using least absolute shrinkage and selection operator (LASSO) regression, and the selected variables were subsequently incorporated into an unpenalized multivariable logistic regression model as the primary clinical model. A nomogram was developed based on the logistic regression coefficients for individual risk estimation. Additionally, 10 machine learning algorithms were compared, and a stacked ensemble strategy was explored as a supplementary analysis to evaluate potential incremental predictive value. Model discrimination, calibration, and clinical utility were assessed using multiple metrics. In the validation stage, 120 AECOPD patients admitted to the same center from October to December 2025 were prospectively enrolled for single-center temporal validation. Model interpretability was provided by the final logistic regression coefficients and the nomogram.
Results: LASSO regression screened four candidate predictors: physical function (PHYS), mental health (PSYCH), environmental support (ENVIR), and quality of life. The selected variables were entered into an unpenalized multivariable logistic regression model as the final clinical tool. The final logistic regression model achieved an AUC of 0.866 (95% CI: 0.819-0.912) in the training set, 0.862 in the internal validation set, and 0.866 (95% CI: 0.772-0.960) in the prospective validation set. In exploratory comparisons, the SVM + LR stacked ensemble demonstrated comparable discrimination to the logistic regression model (AUCs: 0.863, 0.868, and 0.864 in the training, internal validation, and prospective validation cohorts, respectively), but no statistically significant improvement was observed (DeLong test, p = 0.312). Calibration analysis showed good agreement in the training and internal validation sets, whereas miscalibration was observed in the prospective cohort. Decision curve analysis suggested potential clinical utility for risk stratification. Model interpretability was provided by the final logistic regression coefficients and the nomogram.
Conclusion: A four-feature interpretable model was developed to identify AECOPD patients with concurrent depressive symptoms during hospitalization. The model demonstrated satisfactory discriminative performance and may assist early risk stratification; however, multicenter external validation, local recalibration, and decision-impact analysis are required before routine clinical implementation.
Yang T, Thastrup M, Masmas TN et al. · Clin Pharmacokinet
External validation 98%
Abstract
Background And Objectives: Busulfan, used in conditioning regimens prior to haematopoietic stem cell transplantation, has a narrow therapeutic index; therefore, due to pharmacokinetic variability, therapeutic drug monitoring (TDM) is employed to ensure drug exposure levels associated with optimal clinical outcomes. This study aimed to facilitate dose adjustment and potentially reduce the number of samples required for TDM in clinical practice.
Methods: Population pharmacokinetic (popPK) and machine learning (ML) models (Random Forest and XGBoost) were developed using a local, retrospective, extensive-sampling dataset of 67 children (637 observations, Denmark) and externally evaluated using prediction error (PE) on a TDM dataset from another centre with 171 children (1871 observations, Netherlands). Limited sampling schedules were evaluated for both methods.
Results: A one-compartment model was the best data fit, showing time-varying clearance decreases of 10.4% and 13% on Days 2 and 3, respectively, compared to Day 1. The popPK, Random Forest, and XGBoost models performed well on the external dataset for concentration prediction, with median PE ranging from -4.82 to -7.44%, median absolute PE of approximately 15%, and approximately 80% of data predicted within ±30% of the PE. Sampling strategies at 0, 0.5, 1, 4 h or 0, 1, 2, 4 h post-infusion adequately predicted busulfan plasma concentration and exposure using the popPK model.
Conclusions: A new popPK model was developed to support individualised dose adjustments in children using fewer blood samples. Both Random Forest and XGBoost could predict busulfan's plasma concentration with performance like that of the popPK model (population prediction). However, a larger dataset is needed for ML methods to describe a complete pharmacokinetic profile.
The absence of accurate, noninvasive, scalable screening tools keeps early esophageal cancer (EC) detection a global health challenge. Although noncontrast computed tomography (NC CT) is widely accessible, the esophagus is a hollow tubular structure prone to collapse and motion artifacts, making small early malignant lesions difficult to distinguish from normal tissue. Here we developed the Esophageal AI-Guided malignant Lesion Evaluation (EAGLE) model to detect precancerous lesions and cancer from chest NC CT, a task historically considered impossible. EAGLE was trained on 6,813 patients from two centers and validated across 12 centers in three countries involving 80,612 patients in opportunistic and population-based screening settings. For opportunistic screening on existing CT scans, multicenter external test cohorts (eight centers, n = 11,466) achieved 98.5% specificity, with 90.0% sensitivity for cancer and 52.5% for precancerous lesions; low-dose CT (LDCT) validation (two centers, n = 1,607) showed comparable performance, supporting EC screening through lung-cancer screening programs. Calibration in a real-world cohort (three centers, n = 35,402) reduced false positives by 72.7% while preserving sensitivity; prospective hospital validation (n = 17,446) achieved a 42.2% PPV, and real-world low-dose screening (n = 10,959) reached 99.94% specificity. EAGLE also detected precancerous lesions-in paired CT-endoscopy cohorts (two centers, n = 702), sensitivities were 65.0% for precancerous lesions and 78.4% for stage I EC at a higher-sensitivity operating point. Exploratory analyses of a prospectively enrolled cohort suggest that referring high-risk individuals for endoscopy could improve screening efficiency. In conclusion, EAGLE has the potential to serve as a scalable tool for early EC screening. Chictr.org.cn identifier: ChiCTR2300074806 .
Fu ZY, Yu XR, Yang YL et al. · Front Med (Lausanne)
External validation 97%
Abstract
Background: Early identification of high-risk sepsis patients remains challenging. The C-reactive protein-Albumin-Lymphocyte (CALLY) index, which integrates inflammation, nutritional status, and immune function, may hold prognostic value in this setting.
Methods: We retrospectively analyzed sepsis patients from two Chinese hospitals (discovery cohort: n = 695; validation cohort: n = 515). Three machine learning algorithms were applied to identify key predictors. A logistic regression model was constructed, internally validated, and externally tested. Model performance was compared with APACHE II and SOFA scores using DeLong's test.
Results: The non-survivors had markedly lower CALLY values (median 0.2 vs. 0.8, P < 0.001). CALLY, lactate dehydrogenase (LDH), total proteins (TP), and platelet count (PLT) were consistently selected as top predictors across all three machine learning methods. The final model demonstrated good discrimination in the development cohort (AUC = 0.877; 95% CI: 0.847-0.908), with a significantly higher AUC than APACHE II (P < 0.001) and SOFA (P = 0.001). Calibration was satisfactory (Hosmer-Lemeshow P = 0.638), and decision curve analysis indicated clinical net benefit. In external validation, the model retained predictive ability (AUC = 0.920), and CALLY remained significantly lower in non-survivors (P < 0.001).
Conclusion: The CALLY index is an acceptable, readily available biomarker strongly associated with 28-day mortality in sepsis. A prediction model incorporating CALLY, LDH, TP, and PLT offers performance comparable or superior to conventional severity scores and may support early risk stratification in clinical practice, provided that calibration-in-the-large is updated when the model is applied to settings with substantially different baseline mortality.
Christensen ME, Sachs MC, Dunn WG et al. · Br J Haematol
External validation 97%
Abstract
Haematological malignancies are rare in primary care and are hard to predict. Existing prediction models often require a specific working diagnosis and are based on extensive clinical information, access to which may be limited at initial work-up in primary care. We aimed to develop a tool for estimating overall risk of haematological malignancy in primary care patients using simple data inputs. Including all full blood cell counts (FBCs) measured from 2000 to 2016 in 856 403 adult primary care patients in Eastern Denmark, we used machine learning to develop CBC-HEMA, a risk assessment tool using FBCs, age, sex and C-reactive protein measures to stratify 'any haematological malignancy' risk within 6 months, 1 year and 3 years with area under the curve (AUC) of 0.81, 0.78 and 0.71 respectively. Predictions of chronic lymphoid leukaemia and myeloproliferative disease were excellent, while CBC-HEMA was unable to accurately predict non-Hodgkin lymphoma and plasma cell dyscrasia. External validation was conducted in 123 015 primary care patients from Western Denmark with similar results and in 418 410 individuals from the background population cohort UK Biobank with inferior performance showing unfitness in screening healthy populations. The CBC-HEMA https://shiny.sund.ku.dk/CopLab/blood-cancer-risk-prediction/ may support risk assessment in primary care but cannot replace a clinical evaluation.
Objectives: To develop and externally validate machine learning models for predicting disease flares in axial spondyloarthritis (axSpA) using real-world registry data.
Methods: Patients with axSpA receiving biological disease-modifying antirheumatic drugs in the METEOR-SpA registry were analysed at visit level. Flare was defined as an Axial Spondyloarthritis Disease Activity Score (ASDAS) increase ≥0.9 (or Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) increase ≥2) at the next 6-month assessment. Candidate models utilising routine clinical predictors and minimum-redundancy maximum-relevance variable selection were optimised for average precision (AP) to account for class imbalance, evaluated using patient-grouped cross-validation (CV) and externally validated in the Groningen Leeuwarden AxSpA cohort (GLAS) using discrimination, calibration and decision curve analysis (DCA).
Results: After eligibility criteria, 1167 patients and 3865 visits were included from the METEOR-SpA cohort; 618 (52.9%) patients had at least one visit with known flare status. Among them, 170 (27.5%) experienced at least one flare. A ridge logistic regression was selected as the final model with an internal CV receiver operating characteristic plot and area under the curve (ROC-AUC) of 0.72 (95% CI 0.70 to 0.75) and an AP of 0.291 (0.245 to 0.337), retaining eight predictors associated with flare. These were ASDAS (current and previous), female sex, flare history, enthesitis, infliximab exposure, physician global assessment and C reactive protein. In external validation in GLAS, ROC-AUC was 0.63 (95% CI 0.59 to 0.68) and AP 0.142 (0.116 to 0.171). DCA showed a modest positive net clinical benefit at low threshold probabilities.
Conclusions: A reduced logistic-regression model showed moderate internal and modest external discrimination for short-term flare risk in axSpA. While not intended to guide individual pre-emptive therapy modification, the model may support low-risk interventions such as group-level risk stratification or tighter follow-up after further validation.
Jeong J, Heo KN, Kim AJ et al. · J Med Internet Res
External validation 97%
Abstract
Background: Anticoagulants are high-alert medications with substantial risk of serious bleeding, yet dosing and prescribing errors remain common. Although clinical decision support systems (CDSSs) can mitigate these errors, their impact is constrained by alert fatigue and limited interpretability.
Objective: We developed and validated a hybrid CDSS that integrates rule-based logic with machine learning to improve the safe use of anticoagulants.
Methods: This multicenter study used electronic health record data on anticoagulant prescriptions from 3 tertiary hospitals (1 for system development and internal validation and 2 for external validation). The hybrid CDSS combined a knowledge-based rule engine with a machine learning model trained to predict whether an anticoagulant prescription would require pharmacist intervention. The system was iteratively refined through pilot testing, internal validation, and external validation.
Results: A total of 75,200 anticoagulant prescriptions were used for model development. The final hybrid CDSS comprised 44 patient-specific rules and 1129 drug-drug interaction rules, combined with a CatBoost classifier (version 1.2.5; Yandex) for alert prioritization. During internal validation, 88 (18.9%) alerts were generated; all were technically correct; 88.6% (n=78) were deemed clinically relevant; 86.4% (n=76) were considered clinically useful; and 13.6% (n=12) required pharmacist intervention. In external validation across 2 hospitals, alert rates ranged from 22.6% (7/31) to 32.1% (310/966), with 18.8% (22/117) to 57.1% (4/7) of alerts requiring pharmacist intervention. The hybrid CDSS showed strong discrimination (area under the receiver operating characteristic curve 0.871-0.963). No false negatives were identified, but the estimates should be interpreted cautiously given the short validation periods and limited number of intervention-requiring prescriptions.
Conclusions: A hybrid CDSS integrating rule-based logic with machine learning demonstrated high technical accuracy and clinical relevance across multiple institutions, suggesting its potential as a practical tool for supporting pharmacist-led anticoagulant prescription review.
Mairot K, Meunier I, Bocquet B et al. · Ophthalmol Sci
External validation 97%
Abstract
Objective: To develop and validate deep learning models to differentiate choroideremia (CHM), USH2A-associated rod-cone dystrophy, and healthy controls using macular OCT volumes.
Design: Retrospective diagnostic study with external validation.
Subjects: Two hundred sixty-two participants contributed 535 macular OCT volumes acquired on a Heidelberg Spectralis (10 165 B-scans): 99 participants had CHM, 96 had USH2A-associated disease, and 67 were healthy controls.
Methods: Volumes acquired between 2012 and 2021 were standardized to 19 B-scans and split at the patient level into training (76%), validation (12%), and test (12%) sets. Three strategies were compared: (1) a slice-based convolutional neural network (CNN) (ResNet-50) with majority-vote aggregation; (2) a Mixture-of-Experts (MoE) model with learned slice weighting; and (3) a hybrid CNN-Transformer integrating per-slice features across the volume. Two ophthalmologists masked to clinical and genetic data graded the 80 test volumes.
Main Outcome Measures: Volume-level accuracy and weighted F1-score.
Results: On the independent test set (80 volumes: 33 CHM, 29 USH2A, 18 controls), all models achieved high performance (accuracy ≥0.963). The MoE achieved the highest accuracy on the internal test set (accuracy 0.988; 79/80; weighted F1-score 0.988), followed by CNN + vote (accuracy 0.975; 78/80; weighted F1-score 0.975) and the hybrid CNN-Transformer (accuracy 0.963; 77/80; weighted F1-score 0.962). Ophthalmologists achieved lower accuracy (0.875 and 0.863). External validation on an independent Rennes University Hospital data set (n = 28 volumes; CHM = 6, controls = 10, USH2A = 12), processed identically without retraining, yielded accuracy 28/28 for CNN + vote, whereas the MoE and hybrid CNN-Transformer each achieved 26/28.
Conclusions: Deep learning applied to macular OCT volumes accurately distinguished CHM, USH2A-associated rod-cone dystrophy, and healthy controls, and achieved higher observed accuracy than masked human readers in this OCT-only setting. Both learned slice weighting and simple aggregation achieved strong performance, suggesting that increased architectural complexity may not be necessary for this 3-class classification task. Further validation in larger, more diverse, and clinically representative cohorts is required to determine the potential role of such models as complementary diagnostic support.
Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Shuai WL, Fang LX, Qiu JJ et al. · Diabetes Res Clin Pract
External validation 96%
Abstract
Objective: The lipid paradox suggests low LDL-C is paradoxically associated with poor outcomes, yet its joint effect with insulin resistance in acute stroke remains unclear. This study aimed to evaluate the combined association of triglyceride-glucose (TyG) index and LDL-C with mortality and days alive out of hospital (DAOH) METHODS: This multi-center cohort study used MIMIC as the derivation cohort and eICU-CRD as external validation. Multivariable regression, survival analysis, and RCS were used to assess the associations of TyG and LDL-C with mortality and DAOH90. Mediation analysis explored potential mechanisms. Boruta and LASSO selected features for ten machine learning models, with SHAP for interpretation.
Results: Among 3,028 MIMIC and 2,385 eICU patients, TyG showed a positive linear association with mortality, while LDL-C exhibited an L-shaped association. The low LDL-C + high TyG group had the highest in-hospital mortality (OR = 3.36, 95%CI: 2.37-4.76) and shortest DAOH90. Inpatient statin use was associated with lower mortality. WBC statistically accounted for 15.46% of the observed association between TyG and in-hospital mortality. Among multivariable machine-learning models incorporating nine selected predictors, GBM achieved the best performance (AUC = 0.802).
Conclusions: High TyG combined with low LDL-C identifies a high-risk phenotype in acute stroke, significantly associated with adverse outcomes. TyG and LDL-C may serve as accessible biomarkers for risk stratification in acute stroke.
Garrucho L, Joshi S, Kushibar K et al. · IEEE Trans Med Imaging
External validation 96%
Abstract
Breast cancer is the most frequently diagnosed malignancy among women worldwide and a leading cause of cancer-related mortality. Dynamic contrast-enhanced magnetic resonance imaging plays a central role in tumor characterization and treatment monitoring, particularly in patients receiving neoadjuvant chemotherapy. However, existing artificial intelligence models for breast magnetic resonance imaging are typically developed and evaluated using heterogeneous datasets, study populations, and assessment protocols, making direct comparison difficult and limiting understanding of model robustness across institutions and clinically relevant patient subgroups. The MAMA-MIA Challenge was designed to address these challenges by providing a standardized benchmark for the joint evaluation of primary tumor segmentation and prediction of pathologic complete response using pre-treatment magnetic resonance imaging only. The training cohort comprised 1,506 patients from multiple institutions in the United States, while evaluation was conducted on an external test set of 574 patients from three independent European centers to assess cross-continental and cross-institutional generalization. A unified scoring framework combined predictive performance with subgroup consistency across age, menopausal status, and breast density. Twenty-one international teams participated in the final evaluation phase. Results demonstrate substantial performance variability under a common external evaluation framework and reveal trade-offs between overall accuracy and subgroup fairness. The challenge provides standardized datasets, evaluation protocols, and public resources to promote the development of robust and equitable artificial intelligence systems for breast cancer imaging.
Background And Purpose: In MR-guided brachytherapy, organs at risk (OAR) are manually delineated during the treatment planning process while the patient waits for the treatment to start with the applicator in place. This study evaluates the delineation time gain and bias introduction of an in-house created artificial intelligence (AI) model trained with a manually uncurated clinical dataset.
Materials And Methods: An nnU-Net was trained on clinical T2w-MR scans for brachytherapy. OAR and target structures underwent automatic interpolation but no manual recontouring. Following clinical implementation, delineation times and structure sets from 32 individual patients with 64 pulsed dose rate (PDR) treatments were collected prospectively from December 2023 to December 2024. Each patient received two treatment fractions: the first was based on AI-assisted delineations corrected by the oncologist, and the second was with the oncologist delineating from scratch without AI assistance. The reduction in delineation time and differences between the uncorrected AI-based and clinically approved delineations were analysed.
Results: AI-based delineations resulted in a time reduction of 10.1 min (95% CI: [7.4, 12] minutes), corresponding to a 31% decrease in delineation time. The AI-based delineations were generally rated acceptable by oncologists, requiring only minor corrections in most cases. When using AI support, the median of the mean surface distance between the AI and clinically used delineation for all OARs and targets was below 2.1 mm.
Conclusion: AI-based delineation models, trained on clinical data without additional manual recontouring, can reduce delineation time. In the current clinical trial, the delineation time was reduced by 31%.
Alzheimer's disease (AD) classification from structural magnetic resonance imaging (MRI) may benefit from weak supervision that uses clinically meaningful but imperfect supervisory signals. We evaluated a weakly supervised framework in which a multilayer perceptron (MLP) trained on age, sex, and Mini-Mental State Examination (MMSE) scores generated clinical pseudo-labels to initialize a patch-based fully convolutional network (FCN). For 260 Alzheimer's Disease Neuroimaging Initiative (ADNI) training participants, subsequent refinement combined 80% of the preceding MRI-model probability with 20% of the participant's ground-truth diagnostic label. This design preserves a dominant pseudo-label/self-training component while using partial diagnostic guidance to stabilize refinement. The FCN generated whole-brain probability maps, and selected voxel probabilities were classified by a second MLP. The framework was developed using ADNI (n = 417). Using ADNI validation data only, iteration 3 and a classification threshold of 0.5 were selected and then applied unchanged to the held-out ADNI test set and the external AIBL (n = 182), FHS (n = 102), and NACC (n = 265) cohorts. The selected model achieved F1 scores of 0.853 in ADNI, 0.707 in AIBL, 0.765 in FHS, and 0.807 in NACC. These results support the feasibility and cross-cohort transferability of clinical pseudo-label-based weak supervision for MRI classification. The framework is not intended to be label-free; rather, it provides a transparent strategy for integrating imperfect clinical pseudo-labels with partially weighted diagnostic guidance during training.
Delirium is a common and severe complication of sepsis in critically ill patients and is associated with increased mortality and prolonged hospitalization. Early identification of high-risk individuals remains challenging, particularly among non-mechanically ventilated patients who are less frequently represented in prediction studies. Using routinely collected electronic health record data, we performed a retrospective multicenter study to establish and validate an early prediction model for delirium in non-mechanically ventilated adults with sepsis. Patients from the MIMIC-IV database were used for model development, and an independent cohort from the eICU Collaborative Research Database was used for exploratory external assessment. A total of 3,015 patients in the development cohort and 1,119 patients in the exploratory test cohort were included. Among the evaluated algorithms, XGBoost achieved the best discrimination, with an area under the receiver operating characteristic curve of 0.807 in internal validation. The eICU cohort contained only 10 delirium cases (incidence < 1%), forming a sparse-event dataset; although the XGBoost model yielded an AUC of 0.833 in this cohort, the calibration and decision curve analysis results should be interpreted with extreme caution due to limited positive events. Lower Glasgow Coma Scale scores, higher illness-severity indices, exposure to sedative or analgesic agents, and metabolic disturbances such as elevated anion gap and abnormalities in hematocrit and calcium were the strongest contributors to prediction. These predictors align with recognized features of sepsis-associated brain dysfunction. This externally validated model may support early risk stratification and targeted preventive strategies in this vulnerable population.
Kumar B, Lorusso E, Fosso B et al. · Front Microbiol
External validation 93%
Abstract
The gut microbiota is essential to maintain host physiology, and its disruption (dysbiosis) is associated with a wide range of diseases. Machine learning (ML) offers a powerful tool to model species-level microbiome profiles, but classifiers that reliably separate healthy from diseased individuals across independent cohorts are still lacking. In this study, we developed a ML classifiers trained on 7,452 publicly available stool metagenomes spanning 32 studies and 12 diseases, designed to distinguish healthy individuals (absence of a clinically diagnosed disease) from non-healthy individuals (presence of a clinically diagnosed disease) based on species-level gut microbiome profiles. We trained 16 supervised models combining four algorithms (RF, SVM-LIN, SVM-RBF, and LR-ElasticNet) combined with all feature sets and three feature-selection algorithms. Performance was assessed by F1 score and ROC-AUC on held-out test data and externally validated on 642 samples from six independent cohorts, including previously unseen diseases. On the test set, all models achieved F1 scores of 78-86% and ROC-AUC values of 89-95%. An SVM-RBF model using permutation-based feature selection performed best (F1 = 86.6%, ROC-AUC = 95.5%; healthy F1 = 86.6%, non-healthy F1 = 88.7%). Importantly, external validation confirmed the generalizability of the full-feature SVM-RBF model (overall F1 = 70.6%; ROC-AUC = 84.7%), including unseen disease types such as Clostridioides difficile infection (F1 = 90.3%) and type 2 diabetes (F1 = 77.4%). Feature-importance and multivariate analyses revealed both shared and disease-specific microbial signatures, suggesting that the model captures biologically meaningful patterns rather than cohort-specific artifacts. Disease-associated taxa included Klebsiella pneumoniae, Raoultella ornithinolytica, Sutterella wadsworthensis, Gemmiger formicilis, and Lactobacillus crispatus. In contrast, healthy status was consistently associated with commensal species such as Extibacter hylemonae and Ruthenibacterium lactatiformans. These results show that models trained on pooled metagenomes predict gut health status accurately and transfer to independent cohorts, providing a scalable, non-invasive framework and a set of candidate microbial biomarkers for further clinical evaluation.
Many existing deep-learning models for brain-tumor diagnosis report very high accuracy, yet they often suffer from overfitting, limited generalizability, and poor robustness, which reduces their clinical reliability. First, a large and diverse dataset was assembled from multiple publicly available sources to reduce data bias. Next, a series of regularization and calibration techniques were applied, including label smoothing, mixup augmentation (α=0.4), exponential moving average (EMA) of model weights to prevent overfitting, stabilize training, and temperature scaling to calibrate predicted probabilities. Since brain-tumor diagnosis directly affects critical clinical decisions, both model accuracy and reliability of its predictions are essential. For that, six diverse, powerful pretrained backbones (ConvNeXt, EfficientNetV2, DenseNet201, Swin, ViT, and DINOv3) were used as frozen feature extractors under pure transfer learning. On top of these frozen features, lightweight classification heads were trained using concatenation, attention, and gated fusion. Then, the predicted-class probabilities from the selected heads were combined and passed to a logistic-regression meta-learner to produce the final prediction, with the aim of improving accuracy and reliability. This architecture is computationally efficient because only lightweight classifiers and a logistic meta-learner are trained, while the heavy backbones remain frozen. The best-performing variant on TEST2, attn_fp_ens, was further evaluated using synchronized 10-fold cross-validation on the TRAIN set. The best-performing TEST variant, the gated-fusion ensemble with fingerprint features (gated_fp_ens), achieved 99.33% test accuracy and 99.28% macro-F1. Under domain shift on the external hospital dataset (TEST2), the attention-fusion ensemble with fingerprint features (attn_fp_ens) showed the strongest performance among the evaluated variants, achieving 95.16% accuracy and 94.11% macro-F1. The TEST2 dataset was collected from a local hospital for external evaluation.
Gong X, Li C, Chen J et al. · Diabetes Metab Res Rev
External validation 93%
Abstract
Aims: Cardiovascular-kidney-metabolic (CKM) syndrome represents an integrated continuum of metabolic, kidney, and cardiovascular abnormalities. However, the stage-specific metabolic heterogeneity underlying this clinical framework remains incompletely characterised.
Materials And Methods: We performed plasma metabolomic profiling in 1374 participants from the China Multi-Ethnic Cohort across CKM stages 0-4. Participants from Chengdu and Chongqing provinces comprised the discovery cohort (n = 969), whereas those from Yunnan province comprised the validation cohort (n = 405). Stage-associated metabolites were identified using prespecified pairwise comparisons with OPLS-DA and covariate-adjusted limma analyses. Weighted correlation network analysis identified coordinated metabolic modules. Machine-learning models were developed to evaluate discrimination of advanced CKM (stages 3-4) using metabolite signatures independent of conventional CKM-defining variables.
Results: Among 858 endogenous metabolites, 261 unique metabolites were associated with CKM stages, revealing distinct metabolic patterns from early to advanced CKM. Stage 1 was characterised by altered lipid- and bile acid-related metabolites, stage 2 by broader lipid and amino-acid remodelling, and stage 3 by additional carbohydrate, aromatic amino-acid, secondary bile acid, host-microbial, and renal-handling signals. Metabolic separation between stages 3 and 4 was comparatively weak. WGCNA identified a CKM-associated turquoise module, with γ-glutamylvaline as a hub metabolite. A model incorporating age, sex, and eight metabolites derived from the discovery cohort showed favourable performance for distinguishing advanced CKM from earlier stages and achieved an AUROC of 0.874 (95% CI, 0.802-0.931) in the validation cohort.
Conclusions: CKM stages exhibit distinct and non-linear metabolic signatures. A compact metabolomic panel independent of conventional CKM-defining variables may provide complementary molecular information for advanced CKM phenotyping and future risk stratification.
Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by marked molecular, cellular, and clinical heterogeneity. Chaperone-mediated autophagy (CMA) supports adaptation to metabolic and environmental stress, but its cell type-specific distribution and prognostic relevance in PDAC remain unclear.
Methods: Single-cell RNA sequencing data from GSE212966 were analyzed to characterize CMA-related transcriptional states in PDAC and adjacent non-tumor tissues. Bulk transcriptomic data from TCGA-PAAD were used for differential expression analysis, weighted gene co-expression network analysis, and molecular model development, while ICGC PACA-CA and PACA-AU served as independent validation cohorts. Multiple survival machine-learning approaches were compared to establish a CMA-related prognostic model. Hallmark pathway activity, immune infiltration, and predicted drug sensitivity were evaluated between risk groups. KRT19, the highest-weighted model gene, was selected for in vitro validation. In parallel, an independent single-center cohort of 468 patients was analyzed using eight survival machine-learning methods to identify clinical prognostic factors and construct a nomogram.
Results: CMA-related transcriptional activity varied among cell types, with macrophages showing prominent scores and PDAC-derived macrophages exhibiting higher CMA scores than those from adjacent tissues. Integration of TCGA differential expression analysis and WGCNA identified 105 candidate genes. The StepCox [forward] plus random survival forest model showed favorable overall performance, with C-index values of 0.903, 0.678, and 0.733 in the TCGA, PACA-CA, and PACA-AU cohorts, respectively. High molecular risk was associated with enhanced glycolytic, proliferative, and cell cycle-related signaling, increased M0 macrophages, reduced CD8+ T cells, and differential predicted drug sensitivity. KRT19 overexpression promoted PDAC cell proliferation, colony formation, migration, and invasion. In the single-center cohort, N stage, CA125, vascular tumor thrombus, and total bilirubin ranked highest in weighted prognostic importance. The clinical nomogram achieved AUC values of 0.661 and 0.750 for 1- and 3-year overall survival, respectively.
Conclusion: This study identified CMA-related cellular heterogeneity, established a molecular prognostic model that retained prognostic discrimination in two independent validation cohorts, demonstrated the functional relevance of KRT19, and developed an independent clinical prediction tool. These molecular and clinical models provide complementary perspectives on PDAC prognosis and warrant further evaluation in matched prospective cohorts.
Diabetes affects one in ten adults worldwide, yet clinicians lack tools to simultaneously predict which complications a given patient is most likely to develop in the near term. Existing risk models typically address single complications, were developed in specialized cohorts, and use heterogeneous time horizons, limiting their utility for individualized clinical decision-making. Here, we show that machine learning models trained on nationwide U.S. administrative claims data for 400,400 adults with newly diagnosed type 1 or type 2 diabetes can accurately predict the monthly risk of nine acute and chronic complications (cardiovascular disease, cerebrovascular disease, peripheral vascular disease, nephropathy, neuropathy, retinopathy, and hypoglycemic and hyperglycemic crises) with predictions that update dynamically as new clinical data become available. Using Regularized Logistic Regression (GLMnet) and Extreme Gradient Boosting (XGBoost) with walk-forward temporal validation, we demonstrate strong discrimination in external validation against an independent electronic health record cohort (areas under the receiver operating characteristic curve 0.77-0.85 across complications for the best-performing model). The Diabetes Complications Risk Calculator therefore provides encounter-specific near-term risk estimates for multiple diabetes complications using routinely available clinical data, offering a potential framework for personalized risk stratification that could support shared decision-making and population health management across healthcare settings. The generalizability of the Diabetes Complications Risk Calculator to other cohorts will need to be tested.
The main purpose of this study was to investigate the molecular mechanisms underlying radiotherapy resistance in pancreatic cancer by integrating single-cell transcriptomic analysis with multicenter clinical cohorts. Using machine learning algorithms and genomic data, we identified key genes associated with radiotherapy response by analyzing radiotherapy sensitivity in our center's single-cell cohort together with external multicenter cohorts, combined with immune microenvironment remodeling and metabolic reprogramming. Radiotherapy resistance- and prognosis-related genes were identified using a random survival forest (RSF) model with high predictive performance, demonstrating satisfactory accuracy and robustness across both internal and external validation cohorts. Among the identified candidates, PLPP2 emerged as a key immune-related gene. Nomogram construction, survival analysis, and receiver operating characteristic (ROC) curve analysis further confirmed the predictive value and robustness of the radiotherapy resistance risk model. Single-cell transcriptomic profiling and cell-cell communication analyses revealed the cellular distribution of PLPP2 and its critical role in shaping the tumor immune microenvironment. High PLPP2 expression was associated with unfavorable survival outcomes, reduced infiltration of antitumor immune cells, and extensive immune microenvironment remodeling. In vivo experiments further demonstrated the potential of PLPP2 as a biomarker for predicting metabolic status, immune landscape, and responsiveness to immune checkpoint inhibitors in pancreatic cancer. Collectively, PLPP2 may have potential predictive value in stromal remodeling, metabolic reprogramming, immune heterogeneity, and radiotherapy efficacy in pancreatic cancer. These findings provide new insights into the molecular basis of radiotherapy resistance, identify a clinically relevant biomarker for prognosis and therapeutic response, and offer a foundation for precision treatment strategies in pancreatic cancer.
Background: There is a lack of intelligent methodologies that effectively integrate multimodal information to predict bone cement leakage (BCL) during percutaneous kyphoplasty (PKP). This study aimed to develop and validate a deep learning (DL)-based multimodal fusion model that incorporates preoperative CT, MRI, and clinical variables to predict BCL subtypes during PKP.
Methods: This study included a retrospective internal dataset for model training and validation, a prospective internal dataset, and an external dataset for independent testing. The fusion model incorporated preoperative spinal CT, MRI, and structured clinical baseline data within a two-stage framework. The first stage consisted of target vertebra localization based on vertebral segmentation. The second stage comprised a classification module implemented using a multibranch 3D ResNet-50 network. Performance was compared with image-only models, single-modality models, and spine surgeons using the area under the receiver operating characteristic curve (AUC), the area under the precision-recall curve, and other metrics.
Results: The multimodal DL model achieved AUC values ranging from 0.795 to 0.861 in the internal test set and from 0.767 to 0.848 in the external test set for predicting BCL subtypes. Type III leakage demonstrated the highest predictive performance (internal AUC, 0.861; external AUC, 0.848). Overall, the fusion model achieved the highest AUC values and showed superior accuracy and agreement compared with spine surgeons, particularly for Type I (κ: internal, 0.439 vs. 0.030-0.075; external, 0.298 vs. 0.019-0.066) and Type IV leakage (κ: internal, 0.459 vs. 0.133-0.186; external, 0.545 vs. 0.002-0.095).
Conclusion: A two-stage multimodal fusion DL framework enables accurate, reliable, and promisingly generalizable prediction of BCL subtypes in PKP, outperforming spine surgeons and supporting individualized preoperative decision-making.
Hueda-Zavaleta M, Espeche EF, Zea Gamboa F et al. · Trop Med Infect Dis
Prospective 90%External validation 30%
Abstract
Background: Intestinal parasitic infections caused by Giardia lamblia and Ascaris lumbricoides remain a public-health problem in resource-limited settings, where conventional microscopy depends on expert personnel and shows variable sensitivity. Artificial intelligence (AI) could standardize and decentralize diagnosis. This study aimed to design and validate FenoParasite, an AI object-detection software (Azure Custom Vision) for the microscopic identification of G. lamblia cysts and trophozoites and A. lumbricoides eggs in stool samples.
Methods: Diagnostic-accuracy study. The reference standard was consensus microscopy by two expert readers, with a third reader for discordant cases. An internal validation set (n = 159) and a prospective pilot validation set (n = 31) were analyzed. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy (95% Clopper-Pearson CI), AUC-ROC (bootstrap), and Cohen's kappa were computed; the confidence threshold was 90%.
Results: The model achieved a mAP@0.30 of 98.3% (precision 98.2%; recall 96.4%). In internal validation, G. lamblia showed 100% sensitivity, 98.9% specificity, 99.4% accuracy, and AUC 0.98; A. lumbricoides reached 100% across all indices (AUC 1.00). In the prospective pilot validation, sensitivity and specificity were 100% for both taxa; however, the confidence intervals were very wide (lower sensitivity bounds of 39.8% and 75.3%, based on only 4 and 13 reference-positive specimens, respectively), and these estimates are correspondingly imprecise.
Conclusions: FenoParasite showed high agreement with consensus expert microscopy for both a protozoan and a helminth. Because the reference standard was expert microscopy rather than a molecular assay, the reported performance estimates quantify agreement with microscopic reading rather than absolute diagnostic accuracy. These findings remain preliminary. Multicenter validation against molecular reference standards is required before clinical implementation can be considered.
Patients with sickle cell disease (SCD) have highly variable clinical courses that become more heterogeneous over time. As curative therapies such as hematopoietic cell transplantation and gene therapy become more available but remain risky, clinicians need accurate, interpretable tools to identify patients at increased mortality risk and the organ-system complications driving it. We developed Multi-Task DeepHit, a neural-network survival model that uses baseline clinical data and learns from 3-year biomarker trajectories during model development. Once trained, it required only baseline data for mortality prediction. We studied 598 adults with SCD (median age 34 years; 51% female, 2006 - 2025) in one NHLBI cohort and externally validated the model in a separate, non-overlapping NHLBI cohort of 383 adults. Baseline inputs included 68 demographic, laboratory, vital-sign, and echocardiographic covariates. Twelve longitudinal biomarkers captured renal, hepatic, cardiopulmonary, and systemic function. Multi-Task DeepHit outperformed both a two-step statistical/machine-learning model and a survival-only DeepHit model, with better discrimination and lower 5-year prediction error in both cohorts. This improvement reflected true patient-specific trajectories, not added model complexity, as performance fell when trajectories were shuffled. The strongest contributors to predicted mortality were reticulocyte percentage, alkaline phosphatase, right atrial pressure, tricuspid regurgitation velocity, and right atrial area. Lower reticulocyte percentage contributed to higher predicted risk, although this pattern depended on other biomarkers. By leveraging longitudinal biomarker trajectories, Multi-Task DeepHit improves mortality prediction in adults with SCD, supports individualized risk assessment, and identifies patients who may benefit from closer surveillance or more intensive disease-modifying or curative therapies.
Background: Nonunion is a costly and serious complication in trauma surgery. The RUST score can assess tibial healing on radiographs but offers no prediction of nonunion at nine to 12 months. A prediction model integrating demographics, blood tests, and radiomics fills this gap and brings clinical value.
Methods: We collected 1-3 month postoperative X-ray, patient data, and blood tests across three centers including 550 patients and 2,344 X-ray. 13 predictive features were selected via two-stage LASSO with group-wise preselection. A U-Net based segmentation framework standardized bone and implant masks under heterogeneous imaging conditions, enabling robust radiomics extraction. ExtraTrees, LightGBM, SVM, CatBoost, Random forest, Gradient boosting, XGBoost, HistGradientBoosting, MLP, Logistic Regression, ElasticNet, Lasso, AdaBoost, Gaussian NB, and Decision Tree were employed to develop NU model.
Results: A total of 492 patients formed the training cohort and 58 patients formed the external validation cohort. An automated segmentation model achieved mean Dice coefficients of 0.947 for bone/callus and 0.921 for implants. LASSO selected 13 predictors: five radiomic features, seven blood tests, and one clinical variable. The ExtraTrees-based NU model yielded an AUC of 0.891±0.021 in the training cohort, with good calibration and net benefit on decision curve analysis. In external validation, AUC was 0.840. The model enables early nonunion risk stratification within three months after surgery.
Conclusion: The NU model is the first automated multimodal prediction model integrating radiomics, blood tests, and clinical data to predict femoral shaft nonunion within three months after intramedullary nailing, providing a technically scalable solution for early nonunion risk stratification before conventional imaging becomes diagnostic.