Systematic review (SR) is a review of evidence-based studies and it aims to support the clinicians or researchers to find out the best available evidence to a specific problem. SR is usually conducted in the area of nursing and healthcare.
SR requires an exhaustive and systematic search of literature to ensure that all relevant evidence is included. A very important step for a systematic search is to select the databases you want to search within. Note that the databases you select and the search strategies should be described in your review as well.
For reviews in nursing and health science areas, here is a list of core databases to start from.
Medline is also accessible on its own via other platforms:
You may also consider including the following databases depending on your research topic.
See all available databases by subject:
Grey literature "is often used to refer to reports published outside of traditional commercial publishing." (Cochrane Handbook for Systematic Review of Interventions, chapter 4). Examples of grey literature include:
Searching the grey literature is important, because not all evidence is (commercially) published in journal articles delivered by major databases. It is worth noting that the producing bodies of grey literature are essential sources of quality information beyond the control of commercial publishers, as 'publishing' is normally not the primary activity of those bodies.
WorldWideScience.org: "... enables anyone with internet access to launch a single-query search of national scientific databases and portals in more than 70 countries, covering all of the world's inhabited continents and over three-quarters of the world's population. …. It provides simultaneous access to "deep web" scientific databases, which are typically not searchable by commercial search engines.” ~abstracted rom Wikipedia at https://en.wikipedia.org/wiki/WorldWideScience
Some evidence-based journals may not be indexed in core databases you usually search in. These journals may also contain valuable works that can contribute to your systematic review. Consider to cover these journals also in your searching process.
Different databases have different coverage in journal titles. It is worthwhile to examine the coverage of databases you selected, because this determines your search results and will have a direct impact on your review. Here is an overview of the differences in coverage across the core databases.
Title Coverage: Medline vs. CINAHL Complete vs. Embase vs. Cochrane Library vs. PsycINFO
 |
| [Figure 1] |
Note that:
Title Coverage: Medline vs. CINAHL Complete vs. Embase vs. Cochrane Library vs. PsycINFO
vs. Web of Science vs. Scopus
Web of Science and Scopus are two large multidisciplinary citation databases. You may not need to include these two databases for a systematic review, but it's good to know to what extend the core databases are covered in these two. Figure 2 gives you some indications about the title coverage.
Note that:
[Figure 2]
| Medline (via PubMed) | Embase | CINAHL Complete (via Ebscohost) | PsycINFO (via ProQuest) |
|
| Field | Biomedical | Biomedical | Nursing & allied health | Psychological |
| Major subjects covered |
|
Subjects in Medline +
|
|
|
| Year covered | Since 1946 | Since 1937 | Since 1937 | Since 1806 |
| Number of titles |
Over 5,200
|
Almost 8,300 journals
|
Almost 5,500
|
Over 3,000
|
| Number of records | Over 25 million | Over 32 million | Over 6 million | Over 4.5 million |
| Descriptor (Subject Heading) | MeSH | Emtree (see here a comparison of Emtree and MeSH) |
CINAHL headings or MeSH | Thesaurus of Psychological Index Terms |
Here are some sources and references you can refer to if you need additional information.
Sources:
References:
The Venn diagrams are generated by Venn Diagram Maker Online, based on data extracted from the title lists given above (data accurate as of Dec 2016).
