Tootfinder

The Average Patient Fallacy
Alaleh Azhir, Shawn N. Murphy, Hossein Estiri
https://arxiv.org/abs/2509.26474 https://arxiv.org/pdf/2509.26474

The Average Patient Fallacy
Machine learning in medicine is typically optimized for population averages. This frequency weighted training privileges common presentations and marginalizes rare yet clinically critical cases, a bias we call the average patient fallacy. In mixture models, gradients from rare cases are suppressed by prevalence, creating a direct conflict with precision medicine. Clinical vignettes in oncology, cardiology, and ophthalmology show how this yields missed rare responders, delayed recognition of aty…