Effectiveness evaluation matrix/parameters for a SW-HCL app

As we transition our first Active Semantic Documents application,
Active Semantic Electronic Medical Record into our partner organization,
a cardiology practice (see
http://www.w3.org/2005/04/swls/
or http://lsdis.cs.uga.edu/projects/asdoc/ )
we have an opportunity to measure effectiveness of a
SW technology in a live setting.
In this context, I am looking for norms/studies that could
give us percentage of medical records
that have errors/imperfections of a particular type (eg, drug-drug 
interaction,
failure to check on allergy, %age of cases when patient could
have been prescribed same class of drug that is cheaper, etc.).
Thoughts on exactly what to measure (please see the demo 
<http://lsdis.cs.uga.edu/projects/asdoc/index.php?page=1> so
you could see what could be relevant) would be welcome too.
So far we have planned to log each rule activation/violation (drug 
interaction,
drug allergy, %age time physician changed the drug based on
preference/cheaper alternative based on patient's insurance,
diagnosis-treatment mismatch, etc.).

Thanks in advance,

Amit Sheth