>I always figured the long shifts for doctors were some kind of hazing ritual.
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>It means you don't need a night shift and the "medical team" is always together which equates to better training and was supposed to lead to better continuity of care.
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>Those shifts became unworkable as medicine became more and more complex and hands-on. There have been quite a few papers about quality of care including some recent ones that suggest that patient mortality is not adversely affected by mega-shifts, but IME mistakes are more likely after so many hours.
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>These days in the US I think 36-hour shifts and 80-hour weeks are a specified upper limit. Pansies. ;-)

There are two reasons for this situation in USA. Firstly, doctors make so good money that sometimes they cannot say No. Second reason is an inadvertent continuation: US hospitals cannot afford to employ sufficient number of doctors so they rely on residents (physicians-on-training) so much that they force them to work non-stop.