Mapping laboratory test codes to LOINC for a regional health information exchange.

Fully mapping laboratory tests to LOINC greatly increases functionality within a regional data exchange, but it is a costly process. As an inexpensive approach, we defined 53 "clinically significant" labs to map within the Memphis, Tennessee RHIO. These tests comprised a small percentage of unique test codes but a large percentage of laboratory message volume. We propose mapping a few clinically significant laboratory tests can deliver a low cost increase in functionality for a RHIO.