Physicians have been using practice based evidence data to help provide adjunctive information to guide the treatment of their patients for some time. It has been well documented and utilized by multiple medical disciplines where solid evidence based guidelines were unavailable or inadequate, i.e. pediatric oncology. It is not surprising that physicians took the initiative to develop PBE databases to support the treatment of their patients. PEER combines a crowdsourced outcome registry with EEG, an accepted, well-normed test of brain function.