Semantics, Ontology, and Syntax in Health Informatics: Conceptual Distinctions and Practical Implications for Hospital EHR Implementation
Abstract Implementing a modern Electronic Health Record (EHR) in a hospital is fundamentally an exercise in representing, exchanging, and reusing clinical information safely across time, teams, and systems. This requires clarity about three related but distinct notions: syntax (how information is structured and encoded), semantics (what that structured information means), and ontology (a formal, explicit specification of the domain concepts and relations that underpin shared meaning and enable computational reasoning). In this essay I want to distinguish these concepts and demonstrates how their differences translate into concrete design, integration, governance, and patient-safety considerations in real-world hospital EHR implementations. 1. Introduction Hospitals depend on EHRs not only to store a longitudinal patient record, but to coordinate care across departments (e.g., laboratory, pharmacy, radiology, admissions), across professions, and often across organizational boundaries...