Issue 4 of the TSC Support Team digest looks at grey literature resources, and also highlights an issue with Embase that you may or may not have encountered! Don’t forget to let us know if you have any topics you’d like us to cover, or questions you’d like us to investigate: firstname.lastname@example.org.
TSCs often get asked by authors to search the “grey literature”, defined in the Cochrane Handbook as “literature that is not formally published in sources such as books or journal articles”. Grey literature can include conference abstracts, dissertations, theses and reports. Here are some resources we’ve looked at while we’ve been starting to update the TSC Guide (more news on that soon!)…
The HL Wiki, based in Canada, is a great resource for health information specialists, and includes an extensive section on grey literature. It gives you definitions, some background and major trends and some resources to explore.
Open Grey is probably the best known grey literature database. Open Grey was launched in 2011 as a new platform, replacing OpenSIGLE (System for Information on Grey Literature in Europe). SIGLE was created in 1980 to collect and make available grey literature produced in the European Community. It has now grown to include over 800,000 references, including technical reports, doctoral dissertations, some conference abstracts and official publications. You can find some search tips here.
Healthcare Management Information Consortium
Depending on the topic, you may find the Healthcare Management Information Consortium a useful resource. It is compiled by the UK Department of Health and the King’s Fund. It is available to Ovid subscribers and contains reports on topics such as health service policy, quality of health services, occupational health and the regulation and control of medicines.
If you’re searching on a topic that includes psychotherapies or psychosocial conditions, you may find PsycExtra a useful supplement to a search of PsycINFO. PsycExtra includes conference proceedings, patient factsheets and reports. It might be available to you through an institutional subscription via Ovid, Ebsco or Proquest. It is updated bi-weekly.
Dissertation and Theses
There are a few good resources for dissertations and theses. If your institution has a subscription to Proquest, you may have access to their Dissertations and Theses service, which claims to be the most comprehensive thesis database in the world. Search tips can be found here. Some free resources include the British Library’s EThOS service and the Open Access Theses and Dissertations Database, with over 2.8 million abstracts.
EMBASE indexes conference proceedings these days, but if your institution has a subscription to the Web of Science, you may be able to find more, as conference proceedings are available from 1990. A Web of Science subscription may also include access to BIOSIS, a database of research in the life sciences. The subscription service Zetoc also provides access to conference proceedings.
Seeing double with Ovid EMBASE...
Duplicates in Ovid databases
One of the TSC Support Team recently raised an issue around duplicate records on Embase. These are records which are clearly the same, but have different Embase
numbers. Further discussion revealed that there are a high number of duplicates on Embase, and TSCs need to be aware of this when importing records into the CRS. Don’t forget that if you are going to Cochrane Vienna, there is a Q and A session with Embase if you would like to ask them more about how their deduplication system works.
To avoid introducing duplicates into your Ovid searches, we have found a simple way is to deduplicate the search before you export it (note that this only works on search sets smaller than 6000). If you add the line “remove duplicates from [line number]” to the end of your search, the duplicates will be weeded out before you export. See example below:
We raised the issue of duplicates with Ovid, and they said that these can be created when corrected records are added to the database. The record that is retained when you deduplicate in this way is the most recent, corrected, version of the record.