James, this is not a data problem; it is a human factors problem.
Let's say the data was 99.% pure, a very generous assumption, and it imports perfectly. That means out of 5,000 records, 50 were garbage. To find those 50, you still have to look at EVERY SINGLE patient record as the patient comes through. The patient still has to fill out the questionaire form, the receptionist has to review it, question it, and where necessary enter it. Also, as Jon stated, the data that is being imported may be perfect in IT terms, but still totally incorrect. It is the usual problem of GIGO. Our data imports have gone as perfectly as one could expect in terms of the computer system; it was still easier in the long run to start fresh.
