Confusion on NLM’s Policies for PMC, PubMed, and MEDLINE Inclusion

Over at the Scholarly Kitchen, Kent Anderson writes of his frustrations regarding PMC, PubMed and MEDLINE and non indexed journals (particularly the start up journal eLife) in his post, “Something’s Rotten in Bethesda — The Troubling Tale of PubMed Central, PubMed, and eLife.”

I find myself both agreeing and disagreeing with Anderson. 

I agree there is a big problem with the blurring of the lines in the minds of most people (mainly doctors and researchers) regarding PMC, PubMed and MEDLINE.  PubMed houses the citations for PMC articles as well as the citations to articles in journals indexed within MEDLINE.  The problem is that to most normal people PubMed = MEDLINE.  I mention the blurring of the lines between PubMed and MEDLINE in post “Back Door Method to Getting Articles in PubMed: Is Indexing so Important?”  In my post I mention that doctors and researchers think of PubMed and MEDLINE as the same. I likened it to ordering a cola.  “PubMed and MEDLINE have become the Coke/Pepsi of medical databases.  Two different products but people use the terms interchangeably when ordering a cola soft drink.”  I even posted the email of a researcher friend further illustrating how they don’t distinguish between PubMed and MEDLINE and if the article is PMC it is in PubMed and that in their minds it is in MEDLINE.  At the time of my orginal post I questioned the point of actually indexing journal articles since researchers don’t search by index terms and they erroneously think PubMed is Medline.  All they have to do is get into PMC and it can be found in PubMed via keywords (which is how everybody searches these days).

Anderson’s main argument is NLM is acting as competitor to publishers and technology companies, by allowing certain journal publishers to bypass rules for inclusion into PMC and PubMed.  In his argument he brings up the journal eLife a “fledgling funder-backed journal” that was allowed include articles in PMC despite not having published the required 15 articles, not being indexed in MEDLINE, and PMC acting as the sole provider of the articles.  Not only is NLM circumventing the rules for inclusion to its databases but he believes that NLM is acting as the primary publisher to eLife because their articles can only be found on PMC.  Anderson uses JMLA and Journal of Biomolecular Techniques as other examples of journals that NLM acts as the primary publisher.  I don’t know anything about the Journal of Biomolecular Techniques but I disagree with JMLA serving as an example similar to eLife.  As I mention in my comment to his post on Scholarly Kitchen, JMLA has been around since 1911 so it has fulfilled the 15 article requirement and is published by a publisher (who is not PMC) and sends me the print 4 times a year. The journal is indexed in MEDLINE (since 2002).  Additionally the printed edition clearly states that the digital archives of JMLA are on PMC.  I went to PMC today (October 22, 2012) and the October 2012 issue is not available.  So the most recent issue is not online and PMC is acting as the a digital archive. Therefore NLM is not acting as the publisher of JMLA in the way he describes. In the case of JMLA NLM’s PMC is the secondary publisher that he describes, which is the case of many indexed MEDLINE journals. 

Unfortunatley I think Anderson’s argument misses a bigger issue.  The question of quality within the PubMed database.  As I mentioned there is confusion among PMC, PubMed, and MEDLINE.  People searching PubMed will find an article from the PMC that is in a journal that is not indexed in MEDLINE.  However people will erroneously think the article and and journal are in MEDLINE when in fact they are just in PMC.  By allowing non indexed journals into PMC, NLM is basically allowing a back door into PubMed, and by default into MEDLINE.  Of course NLM doesn’t see it as that, because they are one of the few people who can still see a distinction between PubMed and MEDLINE.  Their users (doctors and researchers) do not see the distinction.  To them PubMed is MEDLINE.  This calls into question the quality of the articles in PMC in journals that are not indexed in MEDLINE.   If the journal isn’t good enought to get into Medline then why is the article good enough to be found in PubMed? 


5 thoughts on “Confusion on NLM’s Policies for PMC, PubMed, and MEDLINE Inclusion”

  1. Susan – you see this is where it gets confusing, since Pubmed appears to contain more than Medline and PMC, at least according to their own description. Personally I used PubMed for years whilst being blissfully unaware of Medline, and knowledge of medline has not changed how I use it much either.

    I understand that there are other, possibly better DBs than PubMed, but no-one I know routinely uses anything else, PubMed’s brand has won this round. That is what I meant by “PubMed is king”.

    I am of the firm opinion that librarians are the best thing to be found in libraries (my mother was a librarian), but I think the issue is one of user knowledge – if the vast majority of users don’t think/care that Medline/PubMed indexing equates to a quality filter, then what is the problem with including PMC content that would otherwise not be in either?
    I can see the point that this clutters the PubMed/Medline distinction and database from its purest/initial ideal, but if it is useful to many users then….?
    In my own work I find that PubMed indexes the vast majority of journals I require and access to full-text is a far more vexing barrier than finding suitable articles.

  2. PMC = free digital archive of full-text biomedical and life sciences journal literature (articles and manuscripts) at the U.S. National Institutes of Health. I would not equate that with “low quality.” These may or may not be from journals that are indexed by Medline.

    Medline = index of journal articles from biomedical journals that are peer reviewed.

    PubMed = way to access what is contained in both PMC and Medline.

    JMLA – a journal indexed by Medline because it is biomedical in nature and peer reviewed. It is also indexed in PMC because it is open access because librarians have a thing for making things freely available to everyone – it is our journal so we made it that way.

    Confusing? Maybe if this is not your job. That is why you have librarians, because it is our job. I don’t necessarily understand the ins and outs of catheters enough to stick them in or take them out of people, that is what we have clinicians for. But I understand enough to use my mad searching skills and deep knowledge of databases to find you the best evidence on catheters.

    PubMed is so NOT King. There are databases out there that kick PubMed’s butt. Your librarian knows about them. Be sure the library is funded well enough so that your librarian can access those databases and find you information PubMed can only dream about.

  3. A side note on your posting, RE: At the time of my orginal post I questioned the point of actually indexing journal articles since researchers don’t search by index terms and they erroneously think PubMed is Medline.

    Some like those terms! Just today, I had a new researcher just getting started on literature searching, and he liked the concept of “controlled vocabulary” as one avenue…Talk to anyone in the Taxonomy field, including librarians…

  4. I discussed this in your previous PubMed/Medline post. I think the basic issue is that Medline is a non-existent brand except to those trained to use it, mostly medical doctors and medical librarians. I am neither, but am a researcher and never understood the distinction until your previous article – Pubmed is king. However, as a researcher I am conscious that pubmed is basically a google/alta-vista type index of journals and doesn’t imply quality at all. Perhaps the issue is Medline’s continued insistence that its indexing does imply some sort of quality filter?
    This also goes to the heart of the argument over whether journals are a good/better proxy for quality than authors/articles/citations, (I would suggest the massive skew in citations in most journals indicates not), but we’re unlikely to be solving that one any time soon.

  5. Excellent clarification of the concerns and confusion expressed in Kent Anderson’s piece! Thank you for writing this. To simplify further, it sounds as if librarians, publishers, authors, and consumers are using the same terms to mean very different things, and there is a lack of a common vocabulary for discussing these issues.

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