Regulations intended to reduce resident physicians' work hours have been accompanied by controversy since their introduction in 2003, which mandated an 80-hour workweek for residents. To determine the impact of duty-hours limits on patient safety, researchers evaluated Patient Safety Indicators (PSIs) for postoperative discharges in teaching versus non-teaching hospitals before and after the reform. This study found no clear patterns across PSIs following implementation of duty-hour limits. These results mirror prior studies which have failed to observe an improvement in patient outcomes with reduced resident work hours, suggesting that limiting physician work hours will not be sufficient to augment safety. A previous AHRQ WebM&M perspective discusses the intersection of graduate medical education and patient safety.