Abstracts

Rationale: Identifying individuals with rare epilepsy syndromes in electronic data sources is difficult, in part because of missing codes in the International Classification of Disease system.  Our objectives were: (a) describe representation of rare epilepsies in other medical vocabularies, to identify gaps, and (b) compile synonyms and associated terms for rare epilepsies, to facilitate text and natural language processing tools for cohort identification and population-based surveillance. Methods: We describe representation of 33 epilepsies in three vocabularies: Orphanet, SNOMED-CT, and UMLS-Metathesaurus. We compiled terms for these syndromes via two surveys, correspondence with parent advocates, and review of web resources and standard vocabularies. Results: UMLS-Metathesaurus had entries for all 33 epilepsies, Orphanet 32, and SNOMED-CT 25. The vocabularies had redundancies and missing phenotypes. Emerging epilepsies (SCN2A, SCN8A, KCNQ2, SLC13A5, and SYNGAP related epilepsies) were underrepresented. Survey and correspondence respondents included 160 providers, 375 caregivers, and 11 advocacy group leaders. Each epilepsy syndrome had a median of 15 (range 6-28) synonyms. Nineteen had associated terms, median 4 (range 1-41). Conclusions: We conclude medical vocabularies have gaps in representation of rare epilepsies, which may limit their value for epilepsy research. The complication of synonyms and associated terms is a potential resource for text and natural language processing tool development. Funding: This project was supported by Centers for Disease Control and Prevention Cooperative Agreement number U01DP006089.