Rayyan is a free web-based tool for screening references for a systematic review or other types of reviews. You start off by performing literature searches in selected databases, and then load your search results into a reference manager such as EndNote or Zotero. From there you can generate a file for import into Rayyan.

In Rayyan two or more researchers can go through these references independently and decide which to include in your review and which to exclude, based on predefined inclusion and exclusion criteria. This process is called screening.

Screening

The screening process for systematic reviews (and other literature reviews) consists of two steps:

Titles and abstracts: Two or more persons independently go through all titles and abstracts, selecting references based on predefined criteria for inclusion and exclusion. When the researchers have screened all the references, conflicting decisions are identified and resolved. If the researchers are not able to reach an agreement, a third person should be invited to give their opinion.
Full text: The references that were assessed as relevant in step 1 must now be retrieved in full text. Two or more researchers read the articles and assess them independently based on the predefined selection criteria. At this stage you should state an exclusion reason for each excluded article. Examples of reasons for exclusion might be wrong population or wrong study design.

Rayyan does not have specific functionality for two steps of screening, but you can still use it for both steps. See Screening step 2 - full-text screening.

Selected reading

Hempel, Susanne. (2020). Conducting your literature review (Concise guides to conducting behavioral, health, and social science research series). Washington: American Psychological Association.