Open Access and MEDLINE

MEDLINE is likely the most important scholarly  abstract and indexing database of journals we have. It is a collection of critical evaluated and rigorously cataloged medical journals maintained by the U.S. National Library of Medicine (NLM). The high-level journals within it are indexed with the NLM’s Medical Subject Headings (MeSH) and widely used when creating health policies or making key medical decisions.

MEDLINE is available for free via the larger database, PubMed, but it’s important to note that MEDLINE ≠ PubMed. In the last couple weeks, there have been some important discussions about questionable journals getting indexed in PubMed. MEDLINE has been free of these concerns because of the rigorous evaluation it’s journals must go through. It is one of the better Whitelists for authors trying to avoid publishing in predatory journals.

If you’re a medical/health researcher and you want your research to have an impact – to truly make science and healthcare better – publishing in a Open Access MEDLINE Journal is one of the best ways to do this. Unfortunately, there is no way to find which of your prospective journals are Open Access and indexed MEDLINE without going through them one by one.

This seemed like a relatively easy problem to solve. Below is my attempt.

I wanted to look at two things in MEDLINE

  1. The number of Gold Open Access Journals
  2. The number of Delayed Open Access Journals

The first was rather easy. I exported the lists of journals currently indexed in MEDLINE (5,618) and DOAJ (10,031). I did some data clean-up in excel and isolated all of ISSNs in MEDLINE and ran an comparison formula against the DOAJ ISSNs. I had to do a decent amount of data clean-up in between, but you can view the final result in a Google Spread Sheet (and download my Excel worksheets here).

Just a few clarifications before the big reveal. Not all open access journals are indexed in DOAJ (“Hidden Gold”), but DOAJ was still my best bet for OA info without going through these one-by-one. Also there were 18 MEDLINE journals that I couldn’t export ISSNs for and so those weren’t included in the comparison.

507 MEDLINE journals are Gold Open Access. Only 9% of the 5,618 total journals. A bit of a disappointingly low number. Interestingly, only 189 of these OA MEDLINE journals have the DOAJ Seal of Approval. Also 133 journals do not charge Article Processing Charges. You can find out which journals these are on the Google Sheet.

To find the number of Delayed OA Journals in MEDLINE I had to get a bit creative. I talked about the problems with tracking Delayed OA Journals in my previous blog post. There aren’t any officially maintained maintained or completely trustworthy lists of Delayed OA Journals currently (there should be!), however I did know one place where I could get a list of embargoed medical journals.

There is a list of open medical journals maintained by Flying Publisher named “Free Medical Journals” that libraries use to activate embargoes journals in their Knowledge Bases/Link Resolvers. This list has the embargo dates for journals listed.  There are a few problems with this list, the date coverage can be off and I have no idea exactly how many journals it misses. However, I’ve found it to almost always be a reliable source for information on journals with a one year embargo or less.

Since having an embargo period of a year or less is what we usually mean when we talk about Delayed OA Journals, I chose to export and just look at those journals.

With this data, I found that there are at least 357 Delayed OA Journals in MEDLINE. 6% of the 5,618 journals. You can look through these journals in this Google Sheet (and view my excel worksheets here).

I was hoping these both of these counts would be higher in MEDLINE. The percentage of Gold OA Journals in MEDLINE, 9%, lines up almost perfectly with the percentage of Gold OA Journals currently in the much larger interdisciplinary database, Scopus, which is 10% Gold OA Journals (3759 out of 36378 journals. This info can be obtained from the Scopus Source Title List). Open Access is arguable more important in the health/medicine field, because lives are at risk, so this a bit of a shame.

Also I was a bit surprised at the small number of Delayed OA Journals I found in MEDLINE. Delayed OA seemed to be a much wider adopted practice in the health/medicine field. So much so that I once had a conversation with a senior researcher who thought that all scholarly journals became OA after a year embargo. This could be just the result of the Flying Publisher List not being as complete as I think it is. Or perhaps I should have also looked at journals that get indexed in PubMed Central after an embargo. Either way though, we really do need a stable list of Delayed OA Journals that functions like DOAJ does. Allowing authors and readers to discover these journals and giving publishers an added incentive to keep their embargo polices consistent.

At this point, I’ve looked a few times at how OA journals are indexed in highly used databases. The OA movement still has a long way to go here. With 45% of journal articles published in 2015 being OA, indexing and metadata for OA journals and articles can no longer be ignored. However, this was always going to be the next step. Open information does not mean it is discoverable. Our search tools still have a long way to go for opening up OA content. Some interesting things are happening though, with services like Unpaywall, the addition of open access filters to Discovery Tools, and Web of Science hoping index information on Green and Hybrid open access articles.


About Ryan Regier

Doing Library Stuff. Follow me on twitter at: @ryregier
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3 Responses to Open Access and MEDLINE

  1. Aaron Tay says:

    Just to confirm. Your definition of “Delayed Open Access Journals” and “Gold Open Access Journals” is such that they are mutually exclusive right?

    Besides looking at DOAJ as a reference for a list of OA journals, I’ve recently come across ROAD: the Directory of Open Access scholarly Resources Have you tried it? The advanced search allows you to search by index.

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