ISPO: An Integrated Ontology of Symptom Phenotypes for Semantic Integration of Traditional Chinese Medical Data

Abstract Symptom phenotypes are crucial for diagnosing and treating various disease conditions. However, the diversity of symptom terminologies poses a significant challenge to analyzing and sharing of symptom-related medical data, particularly in the field of traditional Chinese medicine (TCM). This study aims to construct an Integrated Symptom Phenotype Ontology (ISPO) to support data mining of Chinese electronic medical records (EMRs) and real-world studies in the TCM field. We manually annotated and extracted symptom terms from 21 classical TCM textbooks and 78,696 inpatient EMRs, and integrated them with five publicly available symptom-related biomedical vocabularies. Through a human–machine collaborative approach for terminology editing and ontology development, including term screening, semantic mapping, and concept classification, we constructed a high-quality symptom ontology that integrates both TCM and Western medical terminology. ISPO provides 3,147 concepts, 23,475 terms, and 23,363 hierarchical relationships. Compared with international symptom-related ontologies such as the Symptom Ontology, ISPO offers significant improvements in the number of terms and synonymous relationships. Furthermore, evaluation across three independent curated clinical datasets demonstrated that ISPO achieved over 90% coverage of symptom terms, highlighting its strong clinical usability and completeness. ISPO represents the first clinical ontology globally dedicated to the systematic representation of symptoms. It integrates symptom terminologies from historical and contemporary sources, encompassing both TCM and Western medicine, thereby enhancing semantic interoperability across heterogeneous medical data sources and clinical decision support systems in TCM.