Public Health

While recent development of Artificial Intelligence (AI)-based approaches have demonstrated to be effective in predicting risk of ADRD, these have mostly focused on AD subtype, aged and homogenous populations (Grueso et al, 2022; Rahim et al., 2023), thereby limiting their applicability to other types of ADRD and younger populations. Inspired by earlier work (Danso et al 2021), we propose an AI-based deep-learning framework for early detection of ADRD based on heterogeneous and diverse population from midlife (Figure 1).

We obtained two datasets from the European Prevention of Alzheimer's Dementia- EPAD (n = 2096) and PREVENT Dementia Programme (n = 700) available online (AD workbench, 2020). Following procedures described in Danso et al (2018) a harmonised cohort was curated containing individuals with no diagnosis of dementia. We then created three risk groups (High risk = ApoE4 allele and family history of AD; Medium risk = ApoE4 allele but no family history of AD; Low risk = no ApoE4 allele and no family history of AD) following the risk definition by Ritchie & Ritchie (2012). Convolutional Neural Network (CNN) and Long- Short Term Memory (LSTM) models were developed using 5-fold cross validation and then applied optimisation procedures to obtain optimal parameters for the trained models.

The harmonisation resulted in a cohort (n = 2796; mean age =62; range = 40 - 89years; female =57.5%, Caucasian = 95%), containing medical history, physiological, lifestyle, neuroimaging, and sociodemographic features. Overall, CNN outperformed LSTM by 7% points for accuracy and f1-score (Table 1), with mean AUROC scores of 97% and 94% respectively (Figure 2), and mean validation loss scores (CNN = 0.36; LSTM =0.46).

The superior performance of CNN is consistent with the literature and the relatively low validation loss demonstrates its generalisability. While this model is currently optimised for AD with limited features, a Transfer Learning paradigm is being employed to further train the CNN model to predict risk of other AD sub-types after including BioHermes dataset into pipeline. Future work will also explore modifications of the CNN architecture for multimodal features with explainability capabilities.