Explainable Machine Learning for Predicting Deep Vein Thrombosis in Critically Ill Patients with COPD: Development and Multicenter External Validation.
Wang G, Liu T, et al. • International journal of chronic obstructive pulmonary disease • 2026
An XGBoost machine learning model for early prediction of DVT in ICU patients with COPD achieved an AUC of 0.840 in internal validation and demonstrated stable discrimination in two external cohorts, with SHAP analysis identifying prolonged PTT, elevated RDW, reduced SpO2, and increased respiratory rate as important contributors to DVT risk.
Key Findings
Results
DVT occurred in 6.9% of critically ill COPD patients in the study cohort.
Among 6,672 ICU patients with COPD, 462 (6.9%) developed DVT.
Patients were identified from the MIMIC-IV database.
The dataset was randomly divided into training and internal validation cohorts.
The study characterizes DVT as 'a frequent yet underrecognized complication' in this population.
Results
XGBoost was the best-performing model among eight machine learning algorithms evaluated.
Eight machine-learning algorithms were constructed and compared.
XGBoost achieved an AUC of 0.840 (95% CI 0.812–0.868) in the internal validation cohort.
The model demonstrated 'good calibration' as assessed by calibration plots and Brier scores.
Model discrimination, calibration, and clinical utility were assessed using AUC, calibration plots, decision-curve analysis (DCA), and Brier scores.
Results
External validation confirmed stable discrimination of the XGBoost model in two independent cohorts.
External validation was performed in both the MIMIC-III and eICU cohorts.
The paper reports 'stable discrimination' across both external validation cohorts.
This multicenter external validation assessed generalizability beyond the MIMIC-IV development dataset.
Results
SHAP analysis identified prolonged PTT, elevated RDW, reduced SpO2, and increased respiratory rate as the most important predictors of DVT risk.
SHAP (SHapley Additive exPlanations) analysis was applied for both global and individual interpretability.
The four key contributors identified were: prolonged partial thromboplastin time (PTT), elevated red cell distribution width (RDW), reduced oxygen saturation (SpO2), and increased respiratory rate.
SHAP was used to provide both population-level (global) and patient-level (individual) explanations of model predictions.
These features span coagulation, hematologic, and respiratory domains relevant to critically ill COPD patients.
Results
Decision-curve analysis suggested the XGBoost model provides potential clinical benefit across relevant risk thresholds.
DCA was used to assess clinical utility of the model.
The model showed 'potential clinical benefit across relevant risk thresholds' in the decision-curve analysis.
This indicates the model may offer net benefit compared to treating all or no patients across a range of threshold probabilities.
Results
A web-based calculator was developed to facilitate clinical application of the model.
The tool provides 'individualized risk estimates and interpretable explanations.'
The calculator is intended to 'help clinicians identify high-risk patients earlier and support more targeted thromboprophylaxis and imaging surveillance strategies.'
The web-based format was chosen for practical clinical deployment.
Background
Existing risk assessment tools for DVT are not specifically tailored to critically ill COPD patients, motivating development of a COPD-specific model.
The authors state that 'existing risk assessment tools are not specifically tailored to this high-risk population.'
The study aimed to address this gap by developing and externally validating an interpretable machine-learning model specifically for ICU-admitted COPD patients.
DVT is described as 'frequent yet underrecognized' in this population, suggesting current clinical tools may underperform.
What This Means
This research suggests that a type of machine learning model called XGBoost can accurately predict which critically ill patients with chronic obstructive pulmonary disease (COPD) are at high risk of developing deep vein thrombosis (DVT) — dangerous blood clots that form in the deep veins, usually in the legs. The researchers developed the model using data from nearly 6,700 ICU patients, of whom about 1 in 14 (6.9%) developed DVT. The model performed well not only in the original dataset but also when tested on two separate patient databases, suggesting it is robust and may generalize across different hospital settings.
A key feature of this study is that the model is 'explainable' — meaning clinicians can see which factors are driving the risk prediction for each individual patient. The analysis found that four factors were particularly important: a longer clotting time (PTT), a higher variability in red blood cell size (RDW), lower blood oxygen levels (SpO2), and a faster breathing rate. These are all measurements routinely collected in the ICU, meaning the model could be applied without requiring additional testing. The researchers also built a web-based tool to make the model easy to use in clinical practice.
This research suggests that applying this kind of interpretable machine learning tool could help doctors identify COPD patients in the ICU who are most likely to develop DVT earlier than current standard tools allow, potentially enabling more targeted use of blood-thinning medications and imaging tests. Because existing DVT risk scores were not designed specifically for this population, a COPD-tailored model may offer a meaningful improvement in how care is prioritized for these high-risk patients.
Wang G, Liu T, Ji W, Li T, Wang Z, Hu T, et al.. (2026). Explainable Machine Learning for Predicting Deep Vein Thrombosis in Critically Ill Patients with COPD: Development and Multicenter External Validation.. International journal of chronic obstructive pulmonary disease. https://doi.org/10.2147/COPD.S609203