You need to search databases that cover the topic of interest. Different questions require the use of different databases. The journal article databases listed below are frequently used for health sciences systematic reviews. If necessary, you can also view the Database A-Z List below to find additional databases relevant for your topic.
Databases include different journals. You need to search multiple databases published by different companies and agencies in order to find the full scope of relevant literature published.
PubMed and Ovid Medline are both MEDLINE. You only need to search one or the other. Not both.
On average you may search anywhere from 3 to 5 databases. Systematic Reviews of interventions (RCTs) will typically search Pubmed/MEDLINE, Embase, and Cochrane CENTRAL*. If your topic involves allied health consider CINAHL Complete, for mental health PsycINFO. If your topic includes public health / prevalence consider Web of Science. Globally focused topics may want to search LILACS, African Index Medicus or other global databases.
To help identify which databases are best suited for your research try running a simple keyword search in selected databases to see whether it contains significant results. You can also search for published evidence synthesis articles on the main topic of your research study to see which databases they searched.
*Cochrane CENTRAL is a part of The Cochrane Library and is a source for reports of controlled trials. Many researchers also search ClinicalTrials.gov as this resource may contain published reports on trials that are still in progress.
How do I find more database guides & tutorials?
You can search Google Scholar in an effort to capture journal articles missed from other database searches.
SR teams should examine the reference lists and citing articles of studies included in the review to find additional relevant articles missed by database searches. Also known as forward citation searching, consulting Cited by lists for included articles can be done in databases such as Google Scholar, Web Of Science, or Scopus.
For a more detailed explanation, see ITEM 2C: CITATION SEARCHING of the PRISMA-S Explanation and Elaboration document.
Hand searching refers to reading through specific journal table of contents and selecting articles relevant to the research topic to find additional relevant articles missed by database searches. This process can be done electronically for journals that USC Libraries provides online access to.
For a more detailed explanation, see ITEM 2B: MANUAL SEARCHING of the PRISMA-S Explanation and Elaboration document.