More accurate and individualized health predictions will allow for preventative factors to be implemented well in advance. In 2026, we will see the beginning of precision medical forecasting. Just as there have been remarkable advances in weather forecasting with the use of large language models, so will there be for determining an individual's risk of the major age-related diseases (cancer, cardiovascular, and neurodegenerative). These diseases share common threads, such as a long incubation phase before any symptoms are manifest, usually two decades or more. They also have the same biologic underpinnings of immunosenescence and inflammaging, terms that characterize an immune system that has lost some of its functionality and protective power, and the accompanying heightened inflammation.

Worldwide, many millions of people die suddenly and unexpectedly each year, either with or without a prior history of cardiovascular disease. Such events are sparse (once in a lifetime), many victims will not have had prior investigations for cardiac disease and many different definitions of sudden death exist. Accordingly, sudden death is hard to predict. This analysis used NHS Electronic Health Records (EHRs) for people aged $\geq$50 years living in the Greater Glasgow and Clyde (GG\&C) region in 2010 (n = 380,000) to try to overcome these challenges. We investigated whether medical history, blood tests, prescription of medicines, and hospitalisations might, in combination, predict a heightened risk of sudden death. We compared the performance of models trained to predict either sudden death or all-cause mortality. We built six models for each outcome of interest: three taken from state-of-the-art research (BEHRT, Deepr and Deep Patient), and three of our own creation. We trained these using two different data representations: a language-based representation, and a sparse temporal matrix. We used global interpretability to understand the most important features of each model, and compare how much agreement there was amongst models using Rank Biased Overlap. It is challenging to account for correlated variables without increasing the complexity of the interpretability technique. We overcame this by clustering features into groups and comparing the most important groups for each model. We found the agreement between models to be much higher when accounting for correlated variables. Our analysis emphasises the challenge of predicting sudden death and emphasises the need for better understanding and interpretation of machine learning models applied to healthcare applications.

Stroke is the second leading cause of death worldwide. According to the World Health Organization [1], 5 million people worldwide suffer a stroke every year. Of these, one third die and another third are left permanently disabled. In the United States, someone has a stroke every 40 seconds and every four minutes, someone dies [2]. The aftermath is devastating, with victims experiencing a wide range of disabling symptoms including sudden paralysis, speech loss or blindness due to blood flow interruption in the brain [3].