i2b2 is a very good platform on which several institutions can now “standardize” their EHR data. (FACT_OBSERVATION table)
We have developed a system called HealthFlow which has a mode (RetroGuide) where it can be used as a query tool. (This makes is similar to i2b2).
Also, a workflow engine (in HealthFlow prospective mode called FlowGuide) can go beyond cohort estimation and provide research informatics alerts (and also other types of alerts – decision support, quality improvement).
So how exactly HealthFlow builds on top of i2b2? HeatlhFlow can use observation_fact table from i2b2. We want to make it easy for organizations who have invested time into building their i2b2 data import feeds (e.g., Dx, visit data, lab, CPT procedures, ICD9 procedures) to adopt our tool (HealthFlow).
HealthFlow event schema can be seen on HealthFlow Google Code site and is similar to i2b2 event schema.
Code to translate between HealthFlow and i2b2 in both direction is also available on Google Code
Google code site: http://code.google.com/p/healthflow/downloads/list
The schema is also more explained here: http://retroguide.blip.tv
Please note: Google Code HealthFlow site has only some components necessary for building all HealthFlow infrustructure components at a given institution.
This is a blog site for HealthFlow.