Evidence Synthesis Methodologies in the Health Sciences

Most databases allow you to download your search history, which makes it easy to keep track of your exact search strategies and document them according to the methodological and reporting guidelines for your type of evidence synthesis project.

It's common for databases to label this record of your searches something like "search history," "history," or "recent activity." The link, button, or icon you use to obtain a copy of that search history is usually labeled with a term like "download" or "export," or with an arrow pointing down. In some cases you'll need to select all your search rows in order to download them. You may also need to create an account in the database to export search histories.

Below are a few examples of what search history download options look like across various database platforms:

PubMed
Ovid MEDLINE
Embase
EBSCOhost

Concept tables and search diaries are helpful when designing your core search strategy and translating it to other databases. The expectations for reporting your searches are more stringent.

The PRISMA 2020 reporting guidelines require you to:

• Item 6. Specify all databases, registers, websites, organisations, reference lists, and other sources searched or consulted to identify studies. Specify the date when each source was last searched or consulted.
• Item 7. Present the full search strategies for all databases, registers, and websites, including any filters and limits used.

Your core search strategy and an explanation of your methods will be part of your publication; the rest of your searches are typically reported in supplementary materials. In addition to meeting reporting guideline requirements, full documentation of your searches will allow you to rerun them before publication if necessary.

At a minimum, for each search, whether in a database or another information source, you must include:

• Information source name
  • For databases, include both name and platform, e.g. APA PsycInfo on EBSCOhost
• Years included in search
• Date search was executed
• Full search strategies, including limiters
  • In databases, the easiest approach is to download the search history
• Total records retrieved

PRISMA for Searching, also called PRISMA-S or PRISMA-Search, is the extension of PRISMA 2020 that provides guidelines for reporting searches. It has its own checklist that is much more granular than Items 6 and 7 of the PRISMA 2020 checklist. Regardless of what type of evidence synthesis you're performing, following the PRISMA-S guidelines help you report a transparent and reproducible search.

Consult the PRISMA-S checklist and supplementary documents when reporting your searches.