There is no set number of the databases to search for systematic reviews as each search is different and database selection should be guided by the review topic. However, searching between three to five databases is a good recommendation.
The fourth chapter of the Cochrane handbook focuses on searching for and selecting studies.
Google Scholar is not recommended as a replacement for searching across multiple databases because:
Separate database searching versus using the 'Find books and articles' search on the Library website:
Although the Library's Find books and articles search includes the content of most of the databases provided by the University of Lincoln library, the databases do need to be searched separately rather than using this search. This is because the 'Find books and articles' search doesn't facilitate controlled vocabulary term searching which needs to be done by using the subject headings/thesauri within each database. Searching each database separately is also key to the transparency and replicability of the systematic review process as you (and others) can clearly see which databases have been searched and the numbers of results retrieved from each one.
The University of Lincoln Library provides access to over 200 databases. To find the databases most relevant to your subject, see your subject guide or contact your Academic Subject Librarian.
In systematic reviews, it is expected that you search each database separately using both controlled vocabulary and keyword searching and then replicate the search across each database searched. Controlled vocabulary searching involves using the thesaurus within the database to find the pre-set subject term for each keyword. Not all databases will have a thesaurus - Scopus for example does not.
If a database does not have a thesaurus, then only keyword searching can be undertaken.
Searching each database separately allows you to make the most of their advanced features and evaluate the results from each database. The University of Lincoln uses the EBSCO Host platform to host some of our academic databases so the interface will be the same (e.g. MEDLINE, CINAHL and PsycInfo are all EBSCO Host databases).
Some key databases which could be used are listed below:
Full text for nursing and allied health journals with coverage dating back to 1981. Includes RCNi journals.
Access to authoritative medical information on medicine, nursing, dentistry, veterinary medicine, the health care system, pre-clinical sciences, and much more. Created by the National Library of Medicine, MEDLINE uses MeSH (Medical Subject Headings) indexing with tree, tree hierarchy, subheadings and explosion capabilities to search citations from over 4,800 current biomedical journals.
The American Psycholgical Association's database of abstracts of journal articles, book chapters, books and dissertations in psychology and related disciplines. Coverage is from the 19th century to the present.
Abstract and citation database of peer-reviewed research literature from scientific, technical, medical and social sciences fields and, more recently, also in the arts and humanities.
Abstract and index database of articles from academic journals covering the sciences, social sciences, arts and humanities.
Abstract and index database comprising more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books.
This database contains abstracts of systematic reviews, randomised controlled trials and other resources relevant to occupational therapy interventions. Due to a lack of funding for OTseeker, content on OTseeker from 2016 and beyond is not as comprehensive as previously. Therefore, we recommend that users of OTseeker also search for more recent evidence using other freely available search engines and databases such as PEDro, and PubMed.
A free database of thousands of randomised trials, systematic reviews and clinical practice guidelines in physiotherapy. For every trial, review or guideline, there are citation details, an abstract and a link to the full text where possible.
See also the Library's guide to freely available resources at: https://guides.library.lincoln.ac.uk/freeonlinetools
