A large study published out of UCLA Medical School looked at outcomes in more than 500,000 surgeries. The study was designed to see if surgeons-in-training assisting at surgery resulted in a worse surgical outcome and danger to the patients.
The study showed that although the patients who had surgery in training hospitals had a minimal increase in surgical complications, they had a lower risk of dying from their surgeries. Slightly more minor complications, slightly less major complications.
This is data that has been much-needed. The general impression that surgeons-in-training would lead to inferior results is an obvious belief and strongly held by patients. Even surgeons themselves were uncertain if this led to increased issues, but still they recommended patient participation as this is the only way to develop adequately trained surgeons.
This data reassures patients, surgeons, and their trainees: the system works, patients get good care, and patient results are virtually equivalent at such hospitals when surgeons-in-training are involved.