This paper from the Archives of Internal Medicine is notable: nurses make mistakes when giving out medication, and nurses who are frequently interrupted make even more mistakes. This might seem like stating the obvious, but often the obvious needs clarification and evidence.
What next? I am very afraid that this research will be taken up my people who don’t understand how hospitals work, and will result in a protocol which will state that nurses are not to be interrupted, ever, while they are doing the medication round. Far better, I think, to try and work out why these nurses were being constantly called away. Short staffed, sick patients, administrative tasks, not enough doctors going about? Unless one gets to the meaning of what these mistakes are, the mistakes might just get shifted somewhere else.