I spent 2-3 months in the hospital over the course of 2 years with a family member. Shift changes were always stressful...lots of commotion, doing the introductions, getting the entering staff up to speed, making sure that issues/incidents during the previous shift were communicated, etc. etc. I personally think 12 hours is the sweet spot as long as there aren't too many in a row. Even if the error rates are slightly higher, I personally would not be surprised to see better patient outcomes overall than with shorter shifts.