It's so easy to tell based on the comments here who are the 1st/2nd year medical students and who has actually been in the hospital...
30-hour call is not fun. It's miserable, but I would much prefer it for learning purposes compared to having my patient care interrupted every day by an arbitrary 16-hour limit on my duties. During my internal medicine Sub-I as a fourth year student, I learned more in the four weeks I took 30 hour call with the interns than I learned during 12 weeks of internal medicine third year. The reason is that I was able to admit and follow patients during their initial course in the hospital. When you have to take the page in the middle of the night because you didn't adequately address a patient's nausea (or pain or whatever it is) when you first admitted him, you learn about how to manage these things up front. Simply put, if you hand the patient off to the night float and never have to address the problem yourself, you will keep making that mistake.
We had an upper level resident night float system, so when you admitted in the middle of the night, you had to know everything about a patient for rounds the next day because the patient would be new to the resident and attending. This really increased the sense of ownership over patients and encouraged thorough and detailed H&Ps and management plans, even when you were tired at 3:30 am. That said, the night float resident was always there to help, and I never felt like I would have been more prone to mistakes.
The next day, we would follow up progress on patients and then round. All decisions regarding patient care were being made during rounds, so we had attending support in making those decisions. The system was designed to optimize our educational experience and provide good system-level support for avoiding mistakes.
It's also important to point out that once you finish residency and are in practice, there are no hour limits. If you admit a patient to a hospital and then something comes up in the middle of the night that requires your presence, it doesn't mean you're off the hook the next day by noon. You still have to work. Yes, there are more hospitalists and other shift-work type doctors that take care of things, but nearly all specialties will continue to have some form of call. If you don't get training to handle this in residency, there's nothing magical that happens after your residency is over to prepare you for this.
So, yeah, working long hours sleep-deprived sucks. I hate it, but I will vouch for the educational importance of it. I've seen night-float only programs, and the night-float interns don't take the same level of care of the patient. They basically are just trying to manage the acute problems (shortness of breath, nausea, pain) until the day team gets back to handle all the problems. What this results in is essentially a waste of educational experience when you're on night float. You also don't learn about the more complex pathology during this time, and the day teams don't take responsibility for these very real problems that patients often have.
If you want evidence, you'll never get it. It simply would never get approval because it would be considered unethical for some reason or another, especially since there are limited data to support that longer hours = worse patient outcomes. So we'll never know but all hold our own opinions of it. I just have a hard time feeling sorry for myself or anyone else for having to work 30 hour call when my father had to work much longer hours as a resident and my grandfather was a true "resident" (i.e. he basically lived in the hospital).
