Updates to PubMed 2019
Much of the year-end processing activities for PubMed were completed at end of 2018. These included changing and updating the Medical Subject Headings (MeSH) and Supplementary Concept Records for subjects that were not main headings. Perhaps most interesting in this processing was the addition of "Systematic Review" as a publication type.
In an overview of changes, 421 new descriptors (including MeSH) and 20 new publication types were added. For more on these new concepts, as well as those deleted or restructured, visit "Medline Data Changes - 2019" in the NLM Technical Bulletin.