Database SearchingSystematic reviews are meant to be comprehensive, so you will need to build a search strategy that is also comprehensive. You will need to identify each database that will be searched, as well as creating search strategies that work for each database. For example, PubMed uses MeSH terms but CINAHL does not; you cannot simply copy and paste your complex search from PubMed into CINAHL -- each search strategy will be custom tailored to a particular database. A complex search strategy may include using a combination of keywords and subject headings, boolean operators, and any database-specific filter.
Learn more about these search strategies by clicking on the links below.
You will also need to document your search process through a PRISMA Flow Diagram.
Hand SearchingWhen you find a great article, another method for finding similar articles is to scour the bibliography for related references. This will lead you to other resources, which in turn may lead you to even more references. This is a great way to find citations that might not be indexed in large databases or grey literature (see the next section for more information on grey literature). Sometimes all it takes is one really good journal article to get you going.
When you find references in a bibliography, you are looking at older research -- stuff that was written that influenced the newer article or book. But some databases, such as PubMed and Google Scholar, allow you to flip this and search for newer research. If you've found a good article, you can try searching for it in Google Scholar. When you find the article, there will be a link that says, "Cited by ___," with the number of found citations. If you click on the link, you will see all the newer citations that have referenced this article.
Searching Grey Literature"Grey Literature" includes information that is not published in traditional academic routes (i.e., through a journal or a book). This can included research published by government agencies, organizations, and academic institutions. Some examples of grey literature includes:
If you are including grey literature in your systematic review, you will need to create a separate search strategy to locate these materials, as they are often not found in traditional journal databases. A few examples of sources that house grey literature include clinicaltrials.gov and Google Scholar.
