. 2020 Oct 6;8(10):e17376. doi: 10.2196/17376
©Sijia Liu, Yanshan Wang, Andrew Wen, Liwei Wang, Na Hong, Feichen Shen, Steven Bedrick, William Hersh, Hongfang Liu. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 06.10.2020.
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Figure 2.
Hierarchical index structure using the OMOP Common Data Model. NLP: natural language processing.