Not to belabor this ( I know, that is exactly what I am doing), but I hear the following: don't do a data transfer because the data is inaccurate, but oh by the way continue to use the very same data every single day in the extant system until you do change over.
I know many "data experts" recommend re-keying. I think there is a place for data transfer and a place for real time data verification (esp med lists -what a burden keeping those straight).
I have run hundreds of millions of rows through ETL/conversion tools, and even the best tools doesn't fix bad data.
The flip side is what are you going to expend to find and fix bad data?
I'd recommend the hybrid solution of import the data that you want/need, then check data on returning patients - much like practices only scan records of returning patients as they switch over to an EMR from paper charts.
