I recently heard someone say ‘…so if Medline is in Embase then why search, Medline?’ Apart from the fact that I love MeSH (Medical Subject Heading) I couldn’t give them a good explanation! So I decided, like a good librarian, to look it up. Here is a selection of what I found.
PubMed (Medline) came third and Embase fourth in a piece of research looking into the best place to find RCTs (Randomised Controlled Trials) of physical therapy interventions (Michaleff et al., 2011). CENTRAL (available at www.thecochranelibrary.com ) was the best place to find them, with Pedro (a physiotherapy database available at http://www.pedro.org.au/ ) coming in second.
McGill University Health Centre have produced a very informative Embase V Medline factsheet (McGill University Health Centre Libraries, 2013) which highlighted, to me, that Emtree is updated 3 times a year, MeSH is updated annually, and there are more thesaurus terms in Emtree than MeSH.
The North West Medicines Information Centre has a presentation that is available online called ‘searching Embase’ In the presentation there is a slide titled ‘why you still need Medline’ it explains the indexing methods differ between the databases, there are more subheadings in Medline and the fields and limits are different in each database. Obviously this was part of a training session; it would be useful to know Pharmacists’ views following the session.
Elsevier, the publishers of Embase, have a useful document called ‘What are the differences between Emtree and MeSH?’ (Elsevier, 2012) It is no surprise the document favours Emtree, but it does state that the history feature of MeSH maybe useful to some people. It gives the results of a study comparing Emtree and MeSH when searching for new drugs. It concludes that Embase retrieves more results than Medline when searching for new drugs.
Another Elsevier document gives information about the mapping of MeSH subheadings to Embase terms/subheadings and the mapping of publication types (Crowlesmith, 2011).
If you are searching for ‘adverse effects’ in the 2 databases then a more sensitive search can be ‘constructed with greater ease in Embase than in Medline’ (Golder & Loke, 2012b) but “adverse effects filters should be applied with caution in Embase” (Golder & Loke, 2012a). This would be a great discussion at a Clinical Librarians meeting and would help me understand the research, as I am not sure I do at the moment!
A discussion at the LIHNN Big Day Out in March concluded that when in doubt search both Embase and Medline. I am sure there is more information available about the differences and it would be great to hear people’s views on ‘Medline V Embase’.
Crowlesmith, I., 2011. Coverage of Medline in Embase, Available at: http://www.elsevier.com/__data/assets/pdf_file/0017/127331/Coverage-of-Medline-in-Embase.pdf [Accessed May 14, 2014].
Elsevier, 2012. What are the differences between Emtree and MeSH?, Available at: http://www.elsevier.com/__data/assets/pdf_file/0019/127333/Embase_Emtree-and-Mesh-Whitepaper.pdf [Accessed May 14, 2014].
Golder, S. & Loke, Y.K., 2012a. Sensitivity and precision of adverse effects search filters in MEDLINE and EMBASE: a case study of fractures with thiazolidinediones. Health information and libraries journal, 29(1), pp.28–38. Available at: http://www.ncbi.nlm.nih.gov/pubmed/22335287 [Accessed May 14, 2014].
Golder, S. & Loke, Y.K., 2012b. The performance of adverse effects search filters in MEDLINE and EMBASE. Health information and libraries journal, 29(2), pp.141–51. Available at: http://www.ncbi.nlm.nih.gov/pubmed/22630362 [Accessed May 14, 2014].
McEntee, J., Searching Embase. Available at: http://www.ukmi.nhs.uk/filestore/ukmiamt/EMBASEsearchingNationalCourseSep2013.pdf [Accessed May 14, 2014].
McGill University Health Centre Libraries, 2013. Medline v Embase. Available at: http://www.muhclibraries.ca/files/2013/10/embase-vs-medline_EN-FINAL.pdf [Accessed May 14, 2014].
Michaleff, Z.A. et al., 2011. CENTRAL, PEDro, PubMed, and EMBASE are the most comprehensive databases indexing randomized controlled trials of physical therapy interventions. Physical therapy, 91(2), pp.190–7. Available at: http://ptjournal.apta.org/content/91/2/190.long [Accessed May 14, 2014].
Lucy Anderson BA (Hons) MCLIP
Knowledge Specialist: Outreach and Liaison
Pennine Care NHS Foundation Trust