Previously studies have shown that medical residents who are tired perform poorly in areas of judgment and concentration, and that they're at increased risk for car accidents. This is an especially big issue partially because residents work such long hours and it predisposes them to fatigue and sleepiness on a regular basis anyway. The government did put some hourly maximums in place (80 hours per week and no more than 24 hours at a stretch) but the effect this had, be it positive or negative, really hasn't been studied until now.

Even this study, which looked at the resident's performance both before and after a 24 hour shift, is somewhat inconclusive and needs further investigation. It does seem to show, however, that medical residents are still working tired on a regular basis, which in turn puts them at major risk for making serious medical errors.

I really don't understand why, of all the professions, doctors specifically have this kind of demanding and impossible schedule -- people's lives are on the line!