Twelve hour shifts are not new to the healthcare system and in fact, eight hour shifts are in the minority. I think that the full time but three day workweek is the reason that the long shifts are so common and personally, I wouldn't work five days a week again. There has been some criticism that the higher fatigue level of such a work day promotes increases error frequency. I suppose there may be some truth to this but I think the nurse eventually acclimates. Additionally, I think there are advantages in terms of streamlining patient care over two shifts instead of three.
R