Fig. 1

Semantic integration of LOINC-coded laboratory tests in FHIR into HPO terms. a Representative examples of LOINC to HPO mapping. Potassium in blood, a quantitative (Qn) LOINC test, has three potential outcomes, L (lower than normal), N (normal), and H (higher than normal) and is mapped to three corresponding HPO terms. Presence of nitrite in urine, an ordinal (Ord) test, has two possible outcomes, POS (positive) or NEG (negative) and is mapped to either Nitrituria (HP:0031812) or NOT Nitrituria (HP:0031812), respectively. Color of urine, a nominal (Nom) test, has a list of likely outcomes (represented as Systematized Nomenclature of Medicine-Clinical Terms [SNOMED-CT] codes using the SNOMED-CT US extension) and each one is mapped to an HPO term. b Schematic representation of the relevant contents of a FHIR observation for laboratory tests. Each FHIR Observation resource for a LOINC-encoded laboratory test includes an identifier (id) and the name of the patient, the LOINC code and name, the normal reference range and the observed value as well as an interpretation of the result (see Table 1 for a complete list)