"PRISMA stands for Preferred Reporting Items for Systematic Reviews and Meta-Analyses.
It is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses.
The aim of the PRISMA Statement is to help authors improve the reporting of systematic reviews and meta-analyses. We have focused on randomized trials, but PRISMA can also be used as a basis for reporting systematic reviews of other types of research, particularly evaluations of interventions. PRISMA may also be useful for critical appraisal of published systematic reviews, although it is not a quality assessment instrument to gauge the quality of a systematic review. The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram."
"The PRISMA Explanation and Elaboration document explains and illustrates the principles underlying the PRISMA Statement. It is strongly recommended that it be used in conjunction with the PRISMA Statement.
PRISMA is part of a broader effort, to improve the reporting of different types of health research, and in turn to improve the quality of research used in decision-making in healthcare."
Liberati A, Altman DG, Tetzlaff J, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol. 2009;62(10):e1-e34. doi:10.1016/j.jclinepi.2009.06.006
In PRISMA 2020, there are now expanded options depending on where you search and whether you are updating a review. Version 1 of PRISMA 2020 includes databases and clinical trial or preprint registers. Version 2 includes additional sections for elaborating on your grey literature search, such as searches on websites or in citation lists. Both versions are available for new and updated reviews from the Equator Network's PRISMA Flow Diagram page.
|PRISMA 2020 V1 - Databases and Registers||PRISMA 2020 V2 - Databases, Registers, and Grey Literature|
|The PRISMA diagram for Databases
and Registers follows the same format
as the previous 2009 PRISMA diagram
|The PRISMA diagram for Databases, Registers, and Grey Literature
has an additional column on the right side of the diagram for
reporting of grey literature searches and results
Step 1: Preparation To complete the the PRISMA diagram, save a copy of the diagram to use alongside your searches. It can be downloaded from the PRISMA website.
Step 2: Doing the Database Search Run the search for each database individually, including ALL your search terms, any MeSH or other subject headings, truncation (like hemipleg*), and/or wildcards (like sul?ur). Apply all your limits (such as years of search, English language only, and so on). Once all search terms have been combined and you have applied all relevant limits, you should have a final number of records or articles for each database. Enter this information in the top left box of the PRISMA flow chart. You should add the total number of combined results from all databases (including duplicates) after the equal sign where it says Databases (n=). Many researchers also add notations in the box for the number of results from each database search, for example, Pubmed (n=335), Embase (n= 600), and so on. If you search trial registers, such as ClinicalTrials.gov, CENTRAL, ICTRP, or others, you should enter that number after the equal sign in Registers (n=).
NOTE: Some citation managers automatically remove duplicates with each file you import. Be sure to capture the number of articles from your database searches before any duplicates are removed.
Step 3: Remove All Duplicates To avoid reviewing duplicate articles, you need to remove any articles that appear more than once in your results. You may want to export the entire list of articles from each database to a citation manager such as EndNote, Sciwheel, Zotero, or Mendeley (including both citation and abstract in your file) and remove the duplicates there. If you are using Covidence for your review, you should also add the duplicate articles identified in Covidence to the citation manager number. Enter the number of records removed as duplicates in the second box on your PRISMA template. If you are using automation tools to help evaluate the relevance of citations in your results, you would also enter that number here.
NOTE: If you are using Covidence to screen your articles, you can copy the numbers from the PRISMA diagram in your Covidence review into the boxes mentioned below. Covidence does not include the number of results from each database, so you will need to keep track of that number yourself.
Step 4: Records Screened- Title/Abstract Screening The next step is to add the number of articles that you will screen. This should be the number of records identified minus the number from the duplicates removed box.
Step 5: Records Excluded- Title/Abstract Screening You will need to screen the titles and abstracts for articles which are relevant to your research question. Any articles that appear to help you provide an answer to your research question should be included. Record the number of articles excluded through title/abstract screening in the box to the right titled "Records excluded." You can optionally add exclusion reasons at this level, but they are not required until full text screening.
Step 6: Reports Sought for Retrieval This is the number of articles you obtain in preparation for full text screening. Subtract the number of excluded records (Step 5) from the total number screened (Step 4) and this will be your number sought for retrieval.
Step 7: Reports Not Retrieved List the number of articles for which you are unable to find the full text. Remember to use Find@UNC and Interlibrary Loan to request articles to see if we can order them from other libraries before automatically excluding them.
Step 8: Reports Assessed for Eligibility- Full Text Screening This should be the number of reports sought for retrieval (Step 6) minus the number of reports not retrieved (Step 7). Review the full text for these articles to assess their eligibility for inclusion in your systematic review.
Step 9: Reports Excluded After reviewing all articles in the full-text screening stage for eligibility, enter the total number of articles you exclude in the box titled "Reports excluded," and then list your reasons for excluding the articles as well as the number of records excluded for each reason. Examples include wrong setting, wrong patient population, wrong intervention, wrong dosage, etc. You should only count an excluded article once in your list even if if meets multiple exclusion criteria.
Step 10: Included Studies The final step is to subtract the number of records excluded during the eligibility review of full-texts (Step 9) from the total number of articles reviewed for eligibility (Step 8). Enter this number in the box labeled "Studies included in review," combining numbers with your grey literature search results in this box if needed. You have now completed your PRISMA flow diagram, unless you have also performed searches in non-database sources.
To view the PRISMA diagram created after using Covidence to screen references for your review, click the PRISMA button on the main menu of your review in Covidence.
This PRISMA diagram starts with duplicate removal. To have a complete PRISMA diagram, you will need to add the number of results from each database you searched, as well as the number of additional sources you found. Click Export Data to copy and paste the PRISMA data. You can download an editable template for PRISMA and fill in the numbers.
There are many places articles can get lost in the review process. Remember to make sure your PRISMA numbers add up correctly!
Step 6: Included Studies The final step is to subtract the number of excluded articles or records during the eligibility review of full-texts from the total number of articles reviewed for eligibility. Enter this number in the box labeled "Studies included in review," combining numbers with your database search results in this box if needed. You have now completed your PRISMA flow diagram, which you can now include in the results section of your article or assignment.
If you are updating an existing review, use one of these PRISMA 2020 Updated Review templates, which feature an additional box for the number of studies and reports of studies included in the previous search iterations.
When referring to PRISMA 2020, The Equator Network recommends using journal article citations (such as those in our For More Information box) rather than referring to the PRISMA website. If you are not already using a journal article citation, they recommend that you cite one of the original publications of the PRISMA Statement or PRISMA Explanation and Elaboration.