The interoperability between the Spanish version of the International Classification of Diseases and ORPHAcodes: towards better identification of rare diseases

Abstract Background Rare diseases present a wide spectrum of clinical manifestations and severity levels are often poorly known underrepresented, making them difficult to classify. Diagnoses usually coded using the International Classification Diseases (ICD), with its different versions. In Spain, ICD-10-ES (stem from ICD-10-CM–Clinical Modification) is used throughout National Healthcare System since 2016, indistinctively including rare that lack specific code. Orphanet aims provide high-quality resources on diseases. The goal was interrelate classification in order engage tool track diagnosis characterize improvement space for identification patients Spanish System. Methods 5775 disorder level ORPHAcodes were mapped codes by comparing descriptors associated both classifications. then clustered based their assigned chapter redundancy each individual code calculated counting they to. Three groups established: Group 1 (1 ORPHAcode per ICD-10-ES), 2 (between 2–49 ICD-10-ES) 3 (≥ 50 ICD-10-ES). Results Equivalences 1700 established 5664 ORPHAcodes. distribution within showed an aggregation “Q” (> 40%), “G” 14%), “E” (12%) chapters. availability map reached lowest at chapters less than 0.2 available ORPHAcode. Global analysis revealed only 1055 equivalences pertain group 1. contained 3358 634 while 1322 (11 Within chapters, over 30% 45% own highest (group 3) respectively, but under 10% one 1). Conclusions have not enough specificity identify Direct mapping between ICD or integration healthcare system diagnoses codification would enable better detection epidemiological