Semantic Interoperability Key to Data Exchange
ADVANCE for Health Information Executives, September 2008
By Brian Levy, MD
A primary goal of regional health information organizations (RHIOs) and health information exchanges (HIEs) is to give clinicians timely, point-of-care access to patient data, such as diagnoses, lab results and medication lists, across organizational boundaries. If physicians can see what they and other clinicians in the community have done for specific patients, the RHIO or HIE will perform a valuable service.
Even when this information is stored electronically, however, it usually resides in disparate systems that are not interoperable. Although these systems may be able to exchange HL7 messages that are machine-readable, the information within the message may not necessarily be understandable. Not only do clinical and administrative programs use different codes, but a vast number of synonyms may refer to the same concept. For example, there are many terms and abbreviations that mean "hypertension." If you just search for the word "hypertension," you will miss many references to that same concept.
The solution is an approach called semantic interoperability, which relates every term and code to a single concept in a standardized lexicon. Health Language Inc.'s Language Engine, for instance, can link commonly used coding and classification systems, including ICD-9, ICD-10, CPT, LOINC, NDC, HCPCS, RxNorm and other drug terminologies, to each other or to normative clinical concepts based on standard terminologies such as SNOMED-CT.
Using modeling tools to speed up the process, all of the providers within a RHIO can link their codes to the necessary standard vocabularies. For example, all lab codes and terms in lab reports can be mapped to LOINC, the standard lab terminology. While it is labor-intensive to do this for every conceivable test, the mapping of codes for the common tests will accomplish most of what clinicians need.
Say, for example, that a physician wants to look up all the potassium tests that have been done on a patient. Once all the codes and terms for that test used by every RHIO or HIE member have been mapped to the standard concept for that test, the doctor can initiate a search and be confident that every potassium test that the patient has received will pop up on the computer screen in the same section.
Some RHIOs settle for a single view of data with a single sign-on, but that does not give doctors and nurses what they really want. If the information isn't standardized, some of the data won't show up because the system won't understand what you're asking for. If a RHIO is going to provide a useful service that will ensure its sustainability, it must have semantic interoperability.
Dr. Levy is chief medical officer and senior vice president for Health Language, based in Aurora, Colo.