Bernhard Bermeitinger
Title
Dr.
Last Name
Bermeitinger
First name
Bernhard
Email
bernhard.bermeitinger@unisg.ch
ORCID
Phone
+41 71 224 79 17
46 results
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Item type:Publication, Interpretable type 2 diabetes incidence prediction with AutoScore: A model based on standard clinical parameters(2026-02-01) ;Leiherer, Andreas ;Schnetzer, Laura ;Mink, Sylvia ;Mader, ArthurAxel MündleinObjective Accurate prediction of type 2 diabetes mellitus (T2DM) onset is critical to enable timely interventions and preventive strategies. Although machine learning (ML) approaches have shown promise in risk prediction, their complexity often limits clinical implementation. There is a need for interpretable, user-friendly models that retain predictive strength. Methods We studied 904 cardiovascular risk patients without T2DM at baseline, assessing 71 anthropometric, clinical, and laboratory variables. Over a four-year follow-up, 10 % developed T2DM. We applied AutoScore, an interpretable ML framework that generates parsimonious, point-based risk scores, and compared its performance with an optimized Support Vector Machine (SVM) with a linear kernel. The SVM was refined using feature selection, Tomek link removal, and up-sampling to address class imbalance. Results Both approaches consistently identified fasting glucose, OGTT glucose, and the Matsuda index (reflecting glucose-insulin dynamics) as key predictors. The optimized SVM model achieved a higher balanced accuracy (75 % vs. 67 %), specificity (80 % vs. 77 %), and AUC (0.72 vs. 0.69) compared to AutoScore. However, AutoScore, other than the SVM model, relied exclusively on a small set of routinely available accessible parameters and thereby offered superior interpretability and ease of integration into clinical workflows. External validation in an independent cohort further confirmed the robustness of the AutoScore model. Conclusion Although black-box models such as SVM deliver slightly higher predictive accuracy, interpretable frameworks like AutoScore provide clinically actionable risk stratification based on standard data. Their transparency and simplicity make them particularly valuable for real-world decision support.Type:journal articleJournal:International Journal of Medical InformaticsVolume:206Scopus© Citations 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 425-P: Machine Learning Identifies Glypican 4 as Key Predictor of Five-Year Mortality in Heart Failure Patients with Prediabetes or Diabetes(2025-06-20) ;Leiherer, Andreas ;Muendlein, Axel ;Schnetzer, Laura ;Mink, SylviaHeinzle, ChristineIntroduction and Objective: The rise of Big Data necessitates artificial intelligence-driven analyses to extract valuable insights, particularly for risk prediction in high-risk patient populations. This observational study applied machine learning (ML) algorithms to predict 5-year overall mortality in heart failure patients with type 2 diabetes mellitus (T2DM) or prediabetes Methods: A cohort of 290 heart failure patients with T2DM or prediabetes was followed for 5 years, during which 54% of participants died. The dataset comprised 470 variables, e.g. anthropometric, clinical, social, family history, and lifestyle factors. After preprocessing, the data were analyzed using ML techniques implemented in R’s caret package. The dataset was split into training (75%) and test (25%) subsets. Results: Among the ML models tested, the Random Forest algorithm demonstrated the best predictive performance, with a sensitivity of 82%, specificity of 89%, and overall accuracy of 85%. Clinical parameters were the most significant predictors, with the multimorbidity marker Glypican-4, hemoglobin, and glomerular filtration rate identified as the top three contributors. Conclusion: In conclusion, ML-based Big Data analysis holds great potential for predicting mortality risk in pre-/diabetic heart failure patients, paving the way for personalized and timely interventions.Type:journal articleJournal:DiabetesVolume:74Issue:Supplement 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Interpretable type 2 diabetes incidence prediction with AutoScore: A model based on standard clinical parameters(2025-10) ;Leiherer, Andreas ;Schnetzer, Laura ;Mink, Sylvia ;Mader, ArthurAxel MündleinObjective Accurate prediction of type 2 diabetes mellitus (T2DM) onset is critical to enable timely interventions and preventive strategies. Although machine learning (ML) approaches have shown promise in risk prediction, their complexity often limits clinical implementation. There is a need for interpretable, user-friendly models that retain predictive strength. Methods We studied 904 cardiovascular risk patients without T2DM at baseline, assessing 71 anthropometric, clinical, and laboratory variables. Over a four-year follow-up, 10 % developed T2DM. We applied AutoScore, an interpretable ML framework that generates parsimonious, point-based risk scores, and compared its performance with an optimized Support Vector Machine (SVM) with a linear kernel. The SVM was refined using feature selection, Tomek link removal, and up-sampling to address class imbalance. Results Both approaches consistently identified fasting glucose, OGTT glucose, and the Matsuda index (reflecting glucose-insulin dynamics) as key predictors. The optimized SVM model achieved a higher balanced accuracy (75 % vs. 67 %), specificity (80 % vs. 77 %), and AUC (0.72 vs. 0.69) compared to AutoScore. However, AutoScore, other than the SVM model, relied exclusively on a small set of routinely available accessible parameters and thereby offered superior interpretability and ease of integration into clinical workflows. External validation in an independent cohort further confirmed the robustness of the AutoScore model. Conclusion Although black-box models such as SVM deliver slightly higher predictive accuracy, interpretable frameworks like AutoScore provide clinically actionable risk stratification based on standard data. Their transparency and simplicity make them particularly valuable for real-world decision support.Type:journal articleJournal:International Journal of Medical InformaticsScopus© Citations 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 1386-P: Machine Learning Predicts T2DM Incidence Using Basic Clinical and Laboratory Parameters(2025-06-20) ;Leiherer, Andreas ;Schnetzer, Laura ;Mink, Sylvia ;Mader, ArthurMuendlein, AxelIntroduction and Objective: Artificial Intelligence (AI) and Machine Learning (ML) have the potential to improve risk prediction by identifying complex patterns in clinical and laboratory data, surpassing traditional approaches. ML has already shown success in detecting metabolic diseases, including Type 2 Diabetes Mellitus (T2DM). However, the ability to accurately forecast T2DM incidence is even more beneficial, enabling earlier interventions and treatment. Methods: This observational study aimed to leverage ML to predict the 4-year risk of developing T2DM. A cohort of 904 cardiovascular risk patients, initially free of T2DM, was analyzed at baseline, with data including anthropometric measurements, clinical and laboratory parameters, and recent metabolic biomarkers. Over four years of follow-up, 10.2% of the patients developed T2DM. Results: The ML approach, utilizing the Caret package in R, applied 50 variables. Patients were randomly split into training and test cohorts (75:25), with oversampling used to address class imbalance in T2DM incidence. Recursive feature elimination (RFE) was employed to identify the most relevant variables. A Support Vector Machine (SVM) model with a linear kernel demonstrated the most promising predictive performance, achieving a balanced accuracy of 73%, a sensitivity of 74%, a specificity of 71%, and an AUC of 0.727. The top-ranked predictors for T2DM were glucose measurements (2-hour OGTT glucose, fasting glucose, and HbA1c), HDL-cholesterol, and the triglyceride-glucose (TyG) index. Conclusion: In conclusion, ML proves to be a valuable tool for identifying individuals at risk of T2DM, paving the way for personalized medicine through earlier diagnosis and tailored interventions.Type:journal articleJournal:DiabetesVolume:74Issue:Supplement_1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 426-P: Predicting Coronary Stenoses Using Machine Learning to Reduce Unnecessary Angiographies(2025-06-20) ;Leiherer, Andreas ;Schnetzer, Laura ;Mink, Sylvia ;Muendlein, AxelIntroduction and Objective: Coronary angiography is the gold standard for diagnosing coronary artery stenoses, but is invasive and confers potential risks. This study aimed to develop a Machine Learning (ML) model to predict significant stenoses while minimizing false negatives, ensuring accurate risk stratification and better patient selection. Methods: Data from 2,310 patients undergoing coronary angiography were analyzed, with outcomes classified as no stenoses (X0), non-significant stenoses (X1), or significant stenoses (X2). Results: XGBoost, optimized through grid search and 5-fold cross-validation, emerged as the top-performing ML algorithm. Of 114 clinical and laboratory variables, fibrinogen, HbA1c, BMI, waist-hip ratio, TyG index, FGF23, ceramides, and vitamin D - all associated with insulin resistance and diabetes - were identified as key contributors to the ML model (figure). Overall, the model achieved 62.9% accuracy (95% CI: 57.8-67.9). Sensitivity, precision, and F1 score for X2 were 94.7\%, 62.7\%, and 74.5\%. For X0, sensitivity was 37.3%, with precision and F1 scores of 67.6% and 48.1%. Conclusion: This ML-based approach has the potential to reduce unnecessary angiographies and optimize patient selection in clinical practice. Highlighting the relevance of diabetes-linked variables, the study also underscores the potential of metabolic profiling in coronary risk stratification.Type:journal articleJournal:DiabetesVolume:74Issue:Supplement_1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Is More Data Worth the Cost? Dataset Scaling Laws in a Tiny Attention-Only Decoder(IEEE, 2026-05-06); ; ;Städeli, Rico; Training Transformer language models is expensive, as performance typically improves with increasing dataset size and computational budget. Although scaling laws describe this trend at large scale, their implications in controlled, smaller-scale settings remain less explored. In this work, we isolate dataset-size effects using a strongly reduced attention-only decoder architecture. By training on progressively larger power-of-two subsets, we observe smooth performance improvements accompanied by clear diminishing returns, consistent with scaling-law behavior. Using only about 30 % of the training data is sufficient to reach approximately 90 % of the full-data validation token-level accuracy. These results provide actionable insights into dataset scaling in a controlled, component-isolated setting and offer practical guidance for balancing dataset size and computational cost in compute- and data-restricted environments, such as small research labs and exploratory model development.Type:conference paperJournal:2026 IEEE Swiss Conference on Data Science and AI (SDS) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Subset Pretraining for Enhancing Neural Network Training EfficiencyWe propose a novel alternative to traditional randomly sampled mini-batches for gradient computation: using a fixed subset for complete pretraining of a neural network model. This approach enables deterministic convergence instead of a merely probabilistic one, as proven by the stochastic approximation theory, whose prerequisites are frequently violated by popular optimization algorithms. The approach is justified by the hypothesis that the loss minimum of the training set can be expected to be well-approximated by the minima of its subsets. Such subset minima can be computed in a fraction of the time necessary for optimizing with the whole training set. They are also compatible with efficient second-order optimization methods, such as the conjugate gradient optimizer. These methods are particularly efficient in the convex environment of the loss minimum. The image classification datasets MNIST, CIFAR-10, and CIFAR-100, (optionally extended by augmentation of training data) test this hypothesis. The experiments confirm that the models achieve performance equivalent to that when trained with the conventional training scheme. In conclusion, if the overdetermination ratio for the given model and dataset sufficiently exceed unity, even small subsets are representative. This results in a possible reduction of the computing expense to a tenth or less. This paper is an extended version of Spörer et al. [13].Type:conference paperJournal:Communications in Computer and Information ScienceVolume:2703 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Is There an Optimal Depth of Residual Networks?(Springer Nature (Switzerland), 2025-05-03); ; Although deep neural networks have given the name to the domain of "deep learning", it is still an unresolved question of which depth is the best choice for a given task. A large depth brings problems with the convergence of gradientbased learning algorithms through the phenomenon of vanishing gradient. On the other hand, it is a widespread opinion that a small depth has insufficient representational power for many tasks. The discovery of the concept of residual connections-an identity mapping parallel to a conventional layer-has alleviated the convergence problem so that the discussion of optimum depth lost a part of its motivation, resulting in the assumption of "the more the better". The work presented here shows that a shallow architecture of parallel layers has comparable expressive power as a deep stack of residual layers. This is theoretically justified by expanding the residual layer stack analogical to the Taylor expansion, truncating the higher-order terms into a single broad layer composed of original layers in parallel. This hypothesis has been confirmed by computing experiments with the widespread computer vision benchmark datasets MNIST and CIFAR-10. The 6,912 runs have shown that the shallow and the deep architectures do not substantially differ in performance on both training and validation sets if the total number of parameters is equal. The rough equivalence of the two extreme (deep and shallow) architectures suggests the possibility that an intermediary architecture may be superior. Another series of computing experiments disclosed that the performance does not substantially differ even then. The conclusion is that the performance of an architecture depends more substantially on the total number of parameters than on the sequential or parallel connection of layers.Type:conference paperJournal:Communications in Computer and Information ScienceVolume:2454 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, BioMistral-Clinical: A Scalable Approach to Clinical LLMs via Incremental Learning and RAG(The Asian Federation of Natural Language Processing and The Association for Computational Linguistics, 2025-12) ;Chen, Ziwei; The integration of large language models (LLMs) into clinical medicine represents a major advancement in natural language processing (NLP). We introduce BioMistral-Clinical 7B, a clinical LLM built on BioMistral-7B (Labrak et al., 2024), designed to support continual learning from unstructured clinical notes for real-world tasks such as clinical decision support. Using the augmented-clinical notes dataset provided by Hugging Face (2024), we apply prompt engineering to transform unstructured text into structured JSON capturing key clinical information (symptoms, diagnoses, treatments, outcomes). We employ selfsupervised continual learning (SPeCiaL) (Caccia and Pineau, 2021) to achieve efficient incremental training. Evaluation on MedQA (Jin et al., 2021) and MedMCQA (Pal et al., 2022) shows that BioMistral-Clinical 7B improves accuracy on MedMCQA by nearly 10 points (37.4% vs. 28.0%) over the base model, while maintaining comparable performance on MedQA (34.8% vs. 36.5%). Building on this, we propose the BioMistral-Clinical System, which integrates Retrieval-Augmented Generation (RAG) (Lewis et al., 2020) to enrich responses with relevant clinical cases retrieved from a structured vector database. The full system enhances clinical reasoning by combining domain-specific adaptation with contextual retrieval.Type:conference paper - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Machine learning identifies glypican 4 as key predictor of 5-year mortality in heart failure patients with prediabetes or diabetes(Springer Science and Business Media LLC, 2025-08-26) ;Leiherer, A ;Muendlein, A ;Schnetzer, L ;Mink, SHeinzle, CType:conference paperJournal:DiabetologiaVolume:68Issue:S1Scopus© Citations 8