Supplementary Searching
Supplementary searching helps you pick up additional sources that your database search may have missed. There are a variety of strategies that can be used for this stage. Be sure to keep track of these searches. You'll want to reflect them in your PRISMA Flow Diagram and the methods section of your paper.
- Saved searches and alerts - because the Advanced Review process takes such a long time, it is common for new articles to be published on your topic after you have completed your "final search." In order to ensure that you don't miss any, it is recommended that you save your search in your databases and set up an alert to notify you when new items are added.
- Citation chasing - sometimes also called forward and backward citation searching, one of the best ways to identify relevant items is to search through the reference lists of your included studies and to search for newer studies that have in turn cited your included studies. It is also helpful to search the reference lists of any similar scoping or systematic reviews that you identified during your exploratory searching stage.
- Hand Searches - not all of the key journals for your topic are guaranteed to be covered in your chosen databases, and even if they are, many databases won't yet include articles written in the last year to year and a half. Therefore, it is important to search through the titles and abstracts of all articles published in those key journals to see if there are any that were missed by your search. The best place to go for this is the journal's website.
- Contact subject experts - for various reasons, some studies conducted on your topic may not have made it to publication. Throughout the process some names will show up time and again. It is recommended that you reach out to these researchers to ask if they have any unpublished studies they might be willing to share with you and to see if they know of any others that you may be missing.
- Google Scholar Searches - because of the way that the Google Scholar algorithm works, it cannot be searched systematically. However, it can be a good supplemental search tool. You can use a more simplified version of your search strategy and search through the first 3-5 pages of results to see if any new items are revealed.
- Gray Literature Searches - gray literature can be notoriously difficult to identify, and some topics will rely on it more heavily than others. To do your due diligence in identifying gray literature, be sure to check dissertations through a dissertation-specific database. You can also do a basic Google search for organization or government websites that may be publishing reports, white papers, or presentations on your topic. Learn more on the next page.
