LILACS–worth another look?

In Evidence-Based Librarianship on November 7, 2008 by Danielle Tagged: , , , , , , ,

Whiting et al have done an elegant little study on database coverage for studies of test accuracy.  Not surprisingly, they found that Medline had 80% of studies cited by 8 preselected systematic reviews on this topic.  Surprisingly, a database called LILACS (Latin American and Caribbean Literature on the Health Sciences) turned up 6 studies that were not found anywhere else.  I do not know the total number of studies they looked up, but this seems significant.  It is significant to me, as I have never had the opportunity to search LILACS and I’m now wondering what has been overlooked.

Their searches missed 8 studies due to their not being indexed in any databases, and another 22 studies due to the fallibility of the search strategies they had used.

So if you ever get that anxiety-provoking question, ‘Why weren’t these studies picked up in your search?’, then consider the possibility that you may not have really needed that study type filter.  Indexing still has a ways to go in the area of study types.  Most of the time, I simply do not use them.

Or, consider that some papers are simply not indexed in electronic databases.  Hard for many folks to believe, but true.

The day that scientific literature becomes easy to locate will be the day we all start thinking alike and using the same words–I don’t think it will come.  What do you think?


2 Responses to “LILACS–worth another look?”

  1. Hi Danielle,

    This is really interesting stuff. I’ve used LILACS a few times, though nearly all of the stuff on there is Spanish – it would be interesting to know if one would have to be fluent in Spanish to have picked up the six studies.

    I do use filters for study type, when appropriate, though always it’s a combination of indexing terms as well as free text keywords; I agree that indexing of study type leaves much to be desired, particularly in EMBASE (EMTREE). Of course one can always do more and more sensitive searches, but if it leaves you with 10,000 abstracts to go though every single search then it soon becomes a time issue (though it may be OK for REAL systematic reviewers like you).

    There’s also the questions of what value are these last two or three papers. Let’s say you’ve found 20 RCTs but missed a couple – what is the likelihood that the couple you’ve missed will change the outcome of the review. What is the value of imperfect information, as I believe economists might put it. Is it efficient to double your search and assessment time in order to find an extra 5% of information? I’m not saying it isn’t; I’m just posing the question!

  2. Hey Alan,

    Now that I’ve realised that LILACS is free, I am tempted to try it for a relevant topic. Good question about it being mostly Spanish language–that is one of those languages that I can partially understand because it makes sense and is quite regular–I say that now though! Actually, I just had a look, and I think I would have to use Google Translate alongside this database. Cochrane seems to be all over LILACS because of their multi-lingual emphasis.

    What is the value of imperfect information and has anyone done a review on this? The question you ask is a fascinating one about the law of diminishing returns. I am not a perfectionist, but I do spend extra time changing a word to truncate it in hopes of getting a few extra references so that the cut isn’t too severe when all the concepts are ANDed at the end. I think one of the costs of missing studies (and maybe this is a joke, as it is often out of our hands–if the study isn’t indexed, if your child filter knocked it out, etc) is the loss of face for the research team. It has to do with us being perceived as controlling the information rather than hacking through it with our rusty machetes. Often reviewers submit to eyeballing thousands of abstracts because they would rather make the decisions and not have a ‘dumb’ computer do it for them. There isn’t an ideal solution.

    Emtree is annoying, as I could have saved a reviewer time today by bunging out case reports but these are not adequately indexed in Embase. What is the point of labeling everything as an ‘article’? Ridiculous.

    Don’t get me started on the Ebsco Cinahl–why quotation marks around every word or phrase? Why the pop-up warning message whenever I delete a line? WHY!

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