Predicting functional outcomes after a stroke event by clinical text notes: A comparative study of traditional
Yu-Hsiang Su1, Chih-Fong Tsai2
1Division of Neurology, Department of Internal Medicine, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi City, Taiwan.
Health Informatics Journal
|September 17, 2025
Summary
Predicting acute ischemic stroke outcomes is crucial. Traditional machine learning, specifically Support Vector Machine (SVM) with Bag-of-Words (BOW) features, demonstrated superior accuracy over deep learning models for stroke outcome prediction.
Area of Science:
- Neurology
- Medical Informatics
- Machine Learning
Background:
- Accurate prediction of functional outcomes post-acute ischemic stroke is vital for healthcare resource allocation.
- Text mining models for stroke outcome prediction often focus on traditional machine learning, with limited deep learning comparisons.
Purpose of the Study:
- To compare traditional machine learning and deep learning methods for predicting functional outcomes after acute ischemic stroke.
- To evaluate different feature representation techniques for stroke outcome prediction models.
Main Methods:
- Clinical text notes from a Taiwanese hospital were used to develop predictive models.
- Four feature representation techniques were evaluated: Bag-of-Words (BOW), Term Frequency-Inverse Document Frequency (TF-IDF), ELMo, and BERT.
- Four predictive models were tested: k-nearest neighbor (KNN), Support Vector Machine (SVM), Convolutional Neural Network (CNN), and Long Short-Term Memory (LSTM).
Main Results:
- The Support Vector Machine (SVM) classifier with Bag-of-Words (BOW) features achieved the best performance.
- Feature fusion strategies, such as BOW + TF-IDF and BOW + BERT, also showed strong predictive capabilities.
- The BOW + TF-IDF combination with SVM demonstrated the lowest Type I error, minimizing misclassification of patients with poor outcomes.
Conclusions:
- Traditional machine learning methods outperformed deep learning models in this stroke outcome prediction study.
- The combination of BOW + TF-IDF features with SVM provided the most accurate predictions and the lowest risk of false positives.
- This approach offers a robust method for optimizing stroke patient management and resource allocation.


