New Medical Subject Headings (MeSH)
Every year, the Medical Subject Headings (MeSH)—the National Library of Medicine’s (NLM) controlled vocabulary for indexing articles in PubMed—undergo significant updates. The 2025 edition brings several noteworthy changes that can affect how researchers, librarians, and healthcare professionals search and interpret PubMed data. Below, we break down some of the most impactful updates and what they mean for your literature searches.
By the Numbers: MeSH 2025
- Main Headings: 30,956 total, including 192 new headings
- Supplementary Concept Records (SCRs): 323,939 total, with 1,001 newly added
These updates span multiple MeSH categories, with significant growth in:
- Category G: Phenomena and Processes
- Category L: Information Science
New and Updated Publication Types
Scoping Review
A major addition to MeSH 2025 is the new publication type Scoping Review, which describes literature that provides an overview of available evidence without delivering a specific clinical answer. Until now, such reviews were incorrectly indexed under Systematic Review. The new classification allows for more accurate searching and filtering.
Note: Articles previously indexed as Systematic Reviews may now be retroactively updated as Scoping Reviews.
If you’re using PubMed filters like Systematic Review, be aware that these will now exclude Scoping Reviews, even if the articles include phrases like “Scoping Systematic Review” or “Scoping Umbrella Review.”
Network Meta-Analysis
This term now appears in two forms:
- Network Meta-Analysis (publication type): for original reports
- Network Meta-Analysis as Topic: for articles discussing methodology, economics, etc.
Retroactive indexing is planned, and users are encouraged to update their search strings accordingly.
New MeSH Headings and Their Implications
Plain Language Summaries
This new term refers to simplified research article summaries intended for non-expert audiences. These summaries may appear as:
- A few sentences appended to a traditional abstract
- Full plain-language versions of entire articles (often with visual or educational enhancements)
Though not a publication type, the MeSH term Plain Language Summaries helps users locate articles or discussions related to this practice. It’s recommended to also include the term Patient Education Handout in your searches to expand results.
Aging in Place
The term Aging in Place has been promoted from an entry term to a main heading, now a child term of Independent Living. This change allows for more specific article retrieval.
Previously, searching “aging in place” would automatically map to Independent Living due to PubMed’s Automatic Term Mapping (ATM). Now, it will directly map to the new main heading, offering more precision.
Discontinued Publication Types
Several rarely used or outdated publication types will no longer be applied to new citations. However, these terms remain searchable in PubMed and will not be removed from previously indexed citations. Cataloguers will still have access to many of them.
NLM has discontinued indexing use of the following Publication Type terms:
- Autobiography
- Bibliography
- Consensus Development Conference, N.I.H
- Dictionary
- Directory
- Government Publication
- Interactive Tutorial
- Legal Case
- Legislation
- Newspaper Article
- Overall
- Periodical Index
- Portrait
- Scientific Integrity Review
- Technical Report
As with previously discontinued Publication Types, which include “Government Publication,” “Newspaper Article,” “Overall,” and “Scientific Integrity Review,” these Publication Types will continue to exist in MeSH, appear on existing citations, and be searchable in PubMed. However, they will no longer be applied to new citations.
Impact of MeSH Changes on Literature Reviews using Rayyan
MeSH updates bring valuable enhancements that improve the accuracy, specificity, and relevance of PubMed searches. As new terms are indexed and retroactive updates are applied, you may notice fluctuations in search result counts.
While completing your literature reviews using Rayyan, you will notice that Rayyan makes use of MeSH to enrich reference article topics, assist in identifying relevant articles, predicting inclusion decisions, supporting study design classification and presenting publication types as they are reported by PubMed. The information contained in your exported PubMed searches will be used by Rayyan, so the MeSH changes will automatically carry over to Rayyan with the import of your searches.
