Liliya Spencer.

Dementia diagnosis: ensemble model

Two stacked ensembles comprising seven models, built to diagnose dementia with high accuracy and efficiency - with strong potential for real-world clinical application.

Sector
Machine learning, healthcare
Role
Researcher and developer
Scope
Feature analysis, ensemble architecture, tuning, evaluation
Tools
Python, scikit-learn, XGBoost
Dataset
1,000 rows, 24 columns
Year
2024-2025
Correlation and feature analysis for the dementia dataset

The seven models

Two stacked ensembles were developed, each comprising seven models:

  • Random Forest
  • Gradient Boosting
  • AdaBoost
  • Bagging Classifier
  • ExtraTreesClassifier
  • XGBClassifier
  • HistGradientBoosting
The seven base models used in the stacking ensembles

Dataset

The dataset contains 1,000 rows and 24 columns, covering various parameters related to the health and lifestyle factors of people, with a focus on their dementia status.

The dataset's 24 columns

Stacking

To solve the problem of diagnosing dementia in patients, stacking was chosen - it allows the power of different models to be combined, improving the accuracy of the final prediction.

Model training and prediction

Calculation results: high accuracy of the stacking ensemble - Accuracy 1.0, and ideal values of ROC AUC 1.0, Precision 1.0, Recall 1.0 and F1 Score 1.0. For the stacking ensemble these indicate that the model accurately distinguishes between classes and predicts cases of dementia with absolute accuracy.

Metrics for the first stacking ensemble

Optimisation of models

To further improve the models, the GridSearchCV hyperparameter search method from the sklearn.model_selection library was used to tune the hyperparameters of each model.

GridSearchCV hyperparameter tuning

Model configuration

A new model was created for the second stacking ensemble using the obtained hyperparameters. The new ensemble was trained and the time spent was measured. The validity of the results was assessed using cross-validation for the second ensemble, and the results compared.

Training time comparison
Metrics for the second stacking ensemble

Results

The tests showed high accuracy and efficiency of both stacking ensembles, reaching metric values of 1.0, which indicates the model copes successfully with the task.

In the course of improving the models by adjusting the hyperparameters, the indicators of time spent on training and prediction for the second stacking ensemble were improved.

In conclusion, the constructed model can potentially be used as a tool for diagnosing dementia in clinical practice.

The companion project is a convolutional network reading chest X-rays.

Get in touch

Tell me what you’re building.

I’m open to a role where design owns something: the research behind it, the system underneath it, and the people doing the work. Singapore-based and a permanent resident here.