Thanks for the information. I come up with the following comparison on adapter being a Mediator and a separate system.
Being an adapter
We will have as many mediators as legacy EMR systems(EMR instances)
Stand alone service
We will have single adapter but multiple running instances with as many mediators as number of cases arise
I am thinking the adapter as a fit for all.
May be I need to explore more!
Coming to the data format, as you suggested HL7 FHIR Standard should be considered. Now having the special case taken(morbidity reporting in my previous reply), I have seen the measure and measure report resources to be related. But I am not sure on the API(interoperability) part of the FHIR standard in relation to this case. Can you brief on that?