The Accreditation Council for Graduate Medical Education sets rules for most graduate-level training programs for doctors in the United States. In 2003, the group shortened working hours for U.S. doctors-in-training, known as residents. It limited their work duties to 80 hours a week. The move caused some members of the medical community to raise questions. Did the reduced hours give residents enough time to learn the art of medicine? And, would future patients suffer? Now, a study has answers. It found no difference in hospital deaths, hospital readmissions or costs when comparing results from doctors trained before and after the hour limits. The findings appeared in the medical publication BMJ. The debate about how much time hospital residents should work has a long history. The ACGME notes that as early as the 1970s, studies found that residents were more likely to make mistakes when they failed to get enough sleep.