Development and validation of multiple machine learning models for identifying factors associated with walking ability in ischemic stroke patients: a single-center retrospective study with SHAP approach.
Qiu J, Yang X, et al. • Frontiers in neurology • 2026
Random forest achieved optimal discriminative performance for gait impairment in ischemic stroke patients with an AUC of 0.868 in training and 0.681 in testing, with SHAP analysis identifying neutrophil-to-lymphocyte ratio as the top contributing factor among five key variables.
Key Findings
Results
Random forest was the best-performing machine learning model for identifying gait impairment in ischemic stroke patients.
The random forest model achieved an AUC of 0.868 in the training set and 0.681 in the test set.
Six machine learning models in total were developed and compared.
The study enrolled 1,650 patients diagnosed with ischemic stroke, split 70% training and 30% validation.
This was a single-center retrospective cohort study.
Results
Five significant factors associated with walking ability in ischemic stroke patients were identified through feature selection.
The five factors were: neutrophil-to-lymphocyte ratio (NLR), age, gender, occipital lobe lesions, and frontal lobe lesions.
Feature selection was performed using three methods: LASSO regression, the Boruta algorithm, and logistic regression.
Both inflammatory biomarkers and clinical indicators were integrated into the models.
Data collected included clinical, laboratory, and imaging variables.
Results
SHAP analysis identified the neutrophil-to-lymphocyte ratio (NLR) as the top contributing factor to the model's predictions of gait impairment.
SHapley Additive exPlanations (SHAP) analysis was applied to the best-performing model (random forest).
NLR was prioritized as the top contributor among the five selected features.
NLR is an inflammatory biomarker derived from standard complete blood count measurements.
The integration of inflammatory biomarkers with clinical indicators was a key design feature of this study.
Results
Lesion location in the occipital and frontal lobes was associated with walking ability in ischemic stroke patients.
Imaging variables indicating occipital lobe and frontal lobe lesions were among the five significant factors selected.
These imaging variables were identified through the combined feature selection pipeline of LASSO, Boruta, and logistic regression.
Imaging data were collected alongside clinical and laboratory variables.
Results
Age and gender were identified as significant clinical factors associated with walking ability after ischemic stroke.
Age and gender were two of the five factors retained after the multi-method feature selection process.
These demographic variables were identified alongside inflammatory and imaging features.
The study population consisted of 1,650 ischemic stroke patients from a single center.
Conclusions
The machine learning models were described as showing preliminary promise as screening tools for early risk stratification for gait impairment in ischemic stroke patients.
The authors characterize the models as having 'preliminary promise as screening tools for early risk stratification for gait impairment in IS patients.'
The gap between training AUC (0.868) and test AUC (0.681) suggests some degree of overfitting.
This was a retrospective, single-center study, which limits generalizability.
The study was designed to identify factors associated with walking ability rather than to establish causation.
What This Means
This research suggests that machine learning models combining inflammation markers from blood tests with clinical information can help identify which ischemic stroke patients are at risk for difficulty walking. The study analyzed data from 1,650 stroke patients and found that five factors were most important for predicting walking problems: a blood test ratio called the neutrophil-to-lymphocyte ratio (NLR, which reflects inflammation), age, sex, and whether the stroke affected the frontal or occipital lobes of the brain. Among six different machine learning approaches tested, the 'random forest' method performed best, correctly distinguishing patients with and without gait impairment about 68% of the time in new patients.
The neutrophil-to-lymphocyte ratio stood out as the single most influential factor, highlighting the potential role of inflammation in determining stroke recovery outcomes related to walking. The researchers used an interpretability technique called SHAP analysis to make the model's reasoning transparent, showing exactly how much each factor contributed to individual predictions. This kind of explainability is important for clinical tools, as it allows clinicians to understand why the model flags a particular patient as high risk.
This research suggests that combining routine blood inflammation markers with brain imaging and basic patient information could assist clinicians in earlier identification of stroke patients who may need more intensive rehabilitation support for walking recovery. However, since this was a single-center, retrospective study and the model's performance was notably lower when tested on new patients than during training, the findings would need to be confirmed in larger, multi-center studies before being applied in clinical practice.
Qiu J, Yang X, Guo M, Guo W, Guo X, Jia X, et al.. (2026). Development and validation of multiple machine learning models for identifying factors associated with walking ability in ischemic stroke patients: a single-center retrospective study with SHAP approach.. Frontiers in neurology. https://doi.org/10.3389/fneur.2026.1854073