A safety group at Harvard University has looked into the behavior of those in training in hospitals and found that overworked interns made 36 percent more serious medical errors and five times as many diagnostic mistakes during a traditional work shift than their better rested colleagues. More recently, the safety researchers checked interns’ driving habits and found that their odds of crashing more than double as work hours increase. The doctors-in-training also experienced more than five times as many near misses as nonsleep-deprived drivers. “These findings are of particular concern because motor vehicle crashes are the leading cause of death in this age group,” notes Charles Czeisler, Baldino Professor of Sleep Medicine at Harvard Medical School. Interns, men and women in their first year of residency at teaching hospitals, usually are between 24 and 32 years old. Duty hours for interns and other residents have been limited to 80 hours per week by the Accreditation Council for Graduate Medical Education. However, the new standard still allows people to work for continuous stretches of 30 hours. The report appeared in the Jan. 13, 2005 issue of the New England Journal of Medicine.