A University of Florida physician and colleagues have "mythbusted" a notion long held in medical circles: patients at teaching hospitals fare worse in July when new medical graduates start their residency training and older residents take on more responsibilities. A large national study revealed no such "July phenomenon" or "July effect"—at least not in the field of neurosurgery. The findings are published today in the journal Neurosurgery. Previous studies of the July phenomenon in fields such as general surgery, obstetrics, gynecology and internal medicine have yielded inconsistent results, some finding an effect and others finding none. One earlier study of pediatric neurosurgery found no effect, whereas another study found a small effect.