Peer review, a process of evaluating a manuscript by the authors’ professional or academic peers in the same subject area and making recommendations on its acceptance by a journal, is an important practice for ensuring the quality of published literature. Because peer review provides a level of vetting to ensure that the research and research conclusions are sound, it’s important to understand and be able to identify peer reviewed articles when you’re searching the literature for an evidence-based practice project or question, or to answer a patient care question.

Peer-reviewed journals are the best place to be sure that the articles you are looking at are peer-reviewed. However, please keep in mind that some content types published in a journal are never peer-reviewed, such as editorials and letters to the editor.

When searching a database, you may want to narrow down your search to peer-reviewed articles. In some databases, such as PubMed or Web of Science, most articles are peer reviewed. Other databases, such as CINAHL, allow for filtering search results by peer reviewed status.

You may also want to ensure that an article was published in a peer reviewed journal by looking the journal up in a specialized source, such as Ulrich’s Global Serials Directory (Ulrichsweb).

Ulrichsweb offers a wealth of information on individual journals in multiple disciplines. It has separate records for print and online versions of the same journal and offers multiple details, such as the list of databases in which the journal is indexed. It also tells you whether the journal is refereed (another word for ‘peer-reviewed’).

On the search results list you can always tell the refereed status by the presence or the absence of the referee shirt icon to the left of the journal name.

Once you click on a journal title you’re interested in, the journal record will display the Refereed field and the refereed icon (see highlighted field below).

Keep in mind that it’s always advisable to verify the journal’s peer review status directly on the journal’s website (typically linked from the journal’s Ulrich’s record), especially when Ulrich’s does not display the refereed icon and does not have the Referred field in the record.

If you have any questions about peer review or the peer review status of a specific journal, please don’t hesitate to Ask Us!

Overwhelmed with the number of results retrieved in a PubMed search? You can narrow down the results by using PubMed Filters, located to the left of your results. Filters allow you to limit your results based on certain criteria: article type, publication date, age, language, and more.

To see additional filters, click on Select Additional Filters and mark the category(s) of interest. Once checked they will be displayed for you to select them to limit your search.

However, there are some things to consider when using Filters. The majority of Filters rely on MeSH (Medical Subject Headings), and only articles from the journals indexed in Medline have MeSH. And while Medline comprises the majority of PubMed, there is some content found in PubMed which is not indexed in Medline. This can be due to recent publications that are still “In-Process” and awaiting MeSH indexing, or content that is deposited in PubMed through the Open Access initiatives of PubMed Central (PMC).

Since most of the Filters are MeSH, by applying them you automatically limit your search results to Medline content, thus excluding the most recent, In-Process, Medline content and the rest of PubMed. The only Filters that are not MeSH and can be safely applied to your search are ‘Publication dates’ and ‘Languages’.

What if you want to still use the Filters and conduct a comprehensive search or include the In-Process citations? You will need to apply the Filters to retrieve Medline citations and use additional search strategies to retrieve as much of non-Medline content as possible.

Takeaways:

• Medline is not the whole of PubMed.
• Only references from Medline indexed journals are searchable with MeSH (with the exception of the most recent ones which are In-Process).
• Most Filters are MeSH and using them automatically limits your search to Medline processed citations.
• If you still want to use Filters yet to capture both Medline and non-Medline citations you need to devise your search strategies accordingly.
• In case you need help with searching ask your Librarian.