BACKGROUND: The transition from the use of International Classification of Diseases version 9 (ICD-9-CM) diagnostic codes to version 10 (ICD-10-CM/PCS) for all HIPAA covered entities is set to occur on October 1, 2015. This change will significantly impact public health departments that use, receive, interpret, analyze, and report ICD-9 encoded data for syndromic surveillance purposes. The International Society for Disease Surveillance (ISDS), in collaboration with CDC, CSTE, and a workgroup with representatives from local, state, and military surveillance have developed and released a Master Mapping Reference Table (MMRT) that provides the concept mapping for over 130 syndromes that will assist agencies to modify existing database structures, extraction rules, and messaging guides, as well as revise established syndromic surveillance definitions and underlying analytic and business rules to accommodate the ICD-9 to ICD-10 transition.
METHODS: ISDS coordinated a multi-stakeholder work group to review existing syndromic surveillance definitions and compile ICD-9-CM codes that map to these syndromes. These individual ICD-9-CM codes were then mapped to ICD-10-CM codes using General Equivalence Mappings (GEMs). Subsequently, a reverse translation validation process was used to ensure that the appropriate codes were correctly identified. These syndrome-based code groupings were then reviewed by the surveillance community and partner agencies, leveraging clinical and epidemiological expertise, to reach consensus on the final syndrome mappings.
RESULTS: The new MMRT tool provides a key resource to public health practitioners that use syndromic surveillance to update their systems and to be able to correctly identify trends over times that span the transition period using both code sets as well as surveillance activities using exclusively ICD-10 CM.
CONCLUSIONS: The greater level of detail inherent to ICD-10-CM codes will improve the specificity of syndromic surveillance. The development of a consensus-driven MMRT will assist entities with the complex task of translating ICD-9-CM to ICD-10-CM codes. The code translations will also serve to develop standardized syndrome definitions based on conceptual mappings and a deductive development approach from concept to diagnostic codes to syndromes. Finally, the mappings will enable users to address challenges associated with changes in baseline trends as a result of the transition.