. 2020 Aug 17;28(3):427–443. doi: 10.1093/jamia/ocaa196

Table 4.

Examples of community contributed tools integrated within the N3C computing environment

Tool	Description
OHDSI Atlas	OMOP-optimized tools for cohort querying and analysis. Data quality; data and cohort definition; rapid and reliable phenotype development⁸⁷; phenotype performance evaluation⁸⁸; integration of validated phenotypes definitions into study skeletons that learn and validate predictive models⁸⁹^; and execute a variety of comparative cohort study designs using empirically validated best practices.^90–92
LOINC2HPO	Mapping of LOINC-encoded laboratory test results to HPO. Interoperability for lab results or radiologic findings with OMOP CDM; phenotypic summarization for use in machine learning algorithms, semantic algorithms, and knowledge graph-based applications.⁹³
NCATS Biomedical Data Translator	Translational integration with basic research data and literature knowledge. Symptom‐based diagnosis of diseases linked to research‐based molecular and cellular characterizations^94–96; suite of resources include the Biolink Model,⁹⁷ a distributed API architecture, and a variety of KGs covering a range of biological entities such as genes, biological processes, and diseases; the KG-COVID-19⁹⁸ knowledge graph also includes literature annotation.
Leaf	Web-based cohort builder. Study feasibility for clinician investigators with limited informatics skills⁹⁹; hierarchical concepts and ontologies to construct SQL query building blocks, exposed by a simple drag-and-drop user interface.

API: application programming interface; CDM: common data model; HPO: Human Phenotype Ontology; KG: knowledge graph; N3C: National COVID Cohort Collaborative; NCATS: National Center for Advancing Translational Sciences; OHDSI: Observational Health Data Sciences and Informatics; OMOP: Observational Medical Outcomes Partnership.