There's certainly no lack of anti 12 hour shift articles, but they don't have much of anything to back them up. The first article; http://www.ergoweb.com/news/detail.cfm?id=2473
sounds persuasive at first but it only cites two main studies, neither really holds up. The first found (in a relatively small sample group) that 12-hour workers get about 5.5 hours sleep for day shift and 5.2 at night. They did not study 8-hour shift workers. This is a bit lower than the bulk of similar studies show, but the main thing is that studies that do compare 8-hour shift sleep patterns to 12 hour sleep patterns find little to no difference in amount of time slept. Particularly for night shift workers, the short sleep duration is due to day-sleeping, not the amount of time available to sleep. Studies also show significantly more sleep on days/nights off, meaning more overall sleep and less sleep deprivation while at work due to a shorter stretch on.
The review mentioned is from a group of small scale Dutch studies in the 70's.
The last study is actually basically the same study done by the same author two years apart, one specifically on ICU Nurses. The studies did find that shifts greater than
12.5 hours (including a substantial number of 16 hour shifts and even up to more than 23 hours) were more error-prone than 8.5 hour shifts, but when strictly 8.5 hour shifts were compared to 12.5 hour shifts, the odds of an error were actually equal to slightly higher in 8-hour shifts. The needlestick and injury studies were from the same group, and also found significant differences only with shifts greater than 13 hours.
The second article; http://www.wsws.org/articles/1999/se...hift-s06.shtml
is about "shift-work", aka evenings/nights work, not 12 hour shifts. I'm sure we can all agree that working night shift is fatiguing, so why do it more by working 8 hour shifts?
The third refers to no evidence.
What the evidence does show is that for the most part there is no difference in performance, fatigue, errors, or safety; both shift lengths have risk factors for each of these but they appear to cancel each other out in the end. The evidence also shows that neither a strict 8 hour structure or strict 12 hour structure is ideal, instead a mix is best to accommodate Nurses who find either shift to be excessively fatiguing. I know of Nurses who can't physically do 12-hours straight so 8's work for them, there are also Nurses such as myself who can't tolerate the cumulative fatigue of 5 nights a week. For the most part, Nurses will naturally chose a schedule that is the least fatiguing, accommodating that is what guarantees less fatigued nurses and better patient care.