BACKGROUND: Message Mapping Guides (MMGs) are developed by CDC to define the structure and content of HL7 messages that transmit case notification data from public health jurisdictions to the national level for a condition or group of conditions. When a new MMG is implemented by CDC, public health jurisdictions respond by creating compliant messages to submit data to CDC. These messages often originate from an integrated surveillance system and each system has its own method for producing these messages. This abstract outlines a metadata-driven approach that can be used by surveillance systems to accelerate MMG implementations.
METHODS: The most common methods for creating case notification message is to extract the data from the integrated surveillance system and, using a data integration engine, develop MMG-specific coding to create the message. This process is repeated for each new MMG. Using a metadata-driven approach minimizes changes in the data integration engine route (e.g., Orion Rhapsody) for each new MMG. Metadata are defined for each question/answer on the data collection form for the condition(s) and mapped to metadata as defined in the MMG. An intermediate xml is produced containing the question/answer metadata, as well as the actual data for the case. A single route is used in the integration engine to dynamically drive creation of the case notification message using metadata in the xml or lookup tables.
RESULTS: To implement a new MMG, metadata are defined for the questions and answers on the data collection form. Metadata are defined by non-technical staff rather than by a developer writing code. Any information requested in the MMG that is not consistent with established practices is handled through specific code in the Rhapsody route (e.g. combination of 2 concepts into one OBX-segment.) Using this strategy, the time and resources associated with implementing a new MMG within the NEDSS Base System (NBS) were reduced.
CONCLUSIONS: Use of a metadata-driven approach to create case notifications decreases the time needed to implement an MMG. This approach minimizes the amount of MMG-specific data transformation and mapping needed in the integration engine to create the message; however, creation of OBX-segments that vary from established practices may still require specific coding in the integration engine. The methodology implemented by the NBS can be applied to other systems to reduce MMG implementation costs, though initial establishment of this methodology will require an investment of resources.