BACKGROUND: The absence of standardized and harmonized processes for notifiable diseases data collection at the national level has been identified by CSTE as an ongoing challenge and burden to jurisdictions (15-EB-01 “Common Data Structure for NNDs” - http://c.ymcdn.com/sites/www.cste.org/resource/resmgr/2015PS/2015PSFinal/15-EB-01a.pdf). In support of the CDC Surveillance Strategy and the NNDSS Modernization Initiative, NCIRD has been working to develop harmonized HL7 Message Mapping Guides (MMGs) for nationally notifiable conditions for which NCIRD provides subject matter expertise (SME).
METHODS: During early development of each condition-specific MMG, the NCIRD Surveillance Office compares and aligns variables from all data sources (e.g., worksheets, older MMGs, National Electronic Telecommunications System for Surveillance (NETSS), National Electronic Disease Surveillance System Base System (NBS), electronic laboratory reporting, immunization information systems) to identify overlapping and similar concepts across conditions. Opportunities for standardization and harmonization are identified. Outcomes of this process may include changes in wording, introduction of repeating groups, formatting adjustments, removal or addition of certain variables, and/or retention of unique variables needed to preserve data essential to each condition.
RESULTS: There are 6 NCIRD conditions with MMGs far enough along in development to assess the level of harmonization: varicella, pertussis, mumps, measles, rubella, and congenital rubella syndrome (CRS). Across all 6 program area MMGs, an average 77% of all variables on each MMG are harmonized to another MMG (range 58% - 88%). The rubella (88%) and measles (87%) MMGs have the highest percent total harmonization, and CRS (58%) has the lowest percent harmonization. Additionally, across the 6 conditions, harmonization was 95% for vaccine-related variables, 92% for lab-related variables, 80% for lab epidemiology-related variables, and 45% for clinical-related variables.
CONCLUSIONS: Harmonization is possible across clinically and epidemiologically distinct conditions, when supported by Center surveillance infrastructure, cooperation of program SMEs, and collaboration with NMI partners. However, the ability to harmonize may be limited by the uniqueness of the condition, (e.g., CRS at 58% total harmonization), the type of variables (e.g., the clinical category at 45% total harmonization) and the availability of relevant variable repositories. The methods are extensible across program areas.