Every day, hospitals, insurers and clinics generate an enormous record of how medicines actually perform in ordinary patients: who took what, for how long, and what happened next. Randomised trials remain the gold standard, but they are expensive, slow and often never run for the head-to-head questions doctors care about most. The data to answer many of those questions already exists. The hard part is analysing it in a way that is rigorous, repeatable and trustworthy. That is the job of HADES, ...