One would expect, intuitively, that doctors who don’t have to work as many hours, and who don’t have to work more than 16 hours (which in most other lines of work is called a “double” shift), would get more rest and have an overall improved sense of well-being. If the Bell Commission was right, they would also make fewer mistakes.

So one of the findings of this study was a bit of a surprise. The interns thought they were making more mistakes after the new rules took effect.

Notice I didn’t say they actually were making more mistakes, or that they were making more mistakes that caused harm to patients. The authors of the study didn’t say that, because that isn’t what their findings showed. But that didn’t keep the writer for USA Today from saying that. [Is she mistaken? Is this all about selling newspapers? Both?]

So what did the authors find? Well, first, you have to know what they asked. Interns were asked, on a survey, whether they were concerned about having made any major medical errors in the preceding 3 months.

Before the change in work rules, 19.9% said yes; after the change, 22.3% said yes. So, first, although this change reached statistical significance, it’s a pretty small change.

Second, this is a matter of perception. They were more concerned about having made major medical errors. That doesn’t mean they actually had made more errors. It also doesn’t mean they made errors that harmed patients. No one asked them to sit down at the end of every shift and write down whether they thought they had made any serious mistakes- and what they were, so a researcher could read it and decide whether it really was a serious error. The fact that this is a perception is very important, because in recent years doctors have been hearing a lot about medical errors and the importance of identifying and reporting them in order to learn from them and reduce their incidence. It only stands to reason that in this climate, the perception of the occurrence of medical errors might increase, over time, without a change in the reality.

Let us imagine that the perception and the reality do have some connection. What might be the explanation for that? Well, first, the medical interns might be expected to complete the same amount of work in fewer hours. That is likely to increase their level of stress and contribute to error. Second, if shifts are shorter, there will be more changes of shift, meaning more handing off of responsibility for patient care from one doctor to another. Hand-offs are associated with error. We know this. It is not only intuitive, but we have abundant evidence to prove it. And we’re working on that. We are devoting a lot of time and attention to making hand-offs better.