AI-Based STroke Risk fActor Classification and Treatment (ABSTRACT) study

Stroke is a leading cause of death and disability worldwide, costing the UK approximately £26 billion annually. While lifestyle modification and preventative medications reduce risk, 30% of patients with stroke have no identifiable risk factors. Hence, there is a need to better identify individuals who are at risk of stroke, and particularly those for whom the benefit of treatment outweighs the risk.AI-Based STroke Risk fActor Classification and Treatment (ABSTRACT) is a three-phase study that looks to address this issue by (1) using artificial intelligence (AI) to predict stroke risk from routine hospital data, (2) validating models on external datasets and (3) evaluating the clinical utility of AI-guided risk classification. This paper focuses on Phase I.

Phase I has four objectives:Create three separate machine learning (ML) models to predict stroke risk from routine hospital data: one for CT/MRI brain data, one for ECG/echocardiography data and one for laboratory test/previous medical history data.Perform explainability analyses to identify novel stroke risk factors.Calibrate models with real-world probabilities.Combine models into a single ensemble model.

This retrospective observational cohort study will include 9155 patients with stroke and 109 581 controls from southwest England (January 2003 to November 2025). Stroke cases will be identified via the Sentinel Stroke National Audit Programme. CT/MRI, ECG, echocardiography, laboratory tests, ultrasound and medical history data will be obtained from hospital and general practice records. ML techniques will then be trained on these data to predict stroke risk and identify novel stroke risk factors.

This protocol outlines ABSTRACT Phase I's approach to creating a multimodal stroke prediction model. We detail a data handling protocol compliant with UK ethical governance, along with our strategies for data pre-processing and model training.