David Himmelstein of Cambridge Hospital and Harvard Med School (with co-authors) recently published a paper on the effect of computerization of hospitals.
The results, as Computerworld put it: Computers don't save hospitals money
This makes sense, especially when you look at the study. They focused on data collected reported by individual hospitals nationwide between 2003 and 2007. Computerization, especially at the clinical level, is incredibly disruptive. Thus, the efficiencies aren't likely to arise soon.