The publication of the original PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) statement in 2009 ushered in a paradigm shift in the importance of transparent reporting in systematic reviews. The statement is endorsed by several hundred journals and editorial organizations that publish systematic reviews (SRs) across a wide spectrum of research topics and it’s widely accepted as one of the benchmarks in systematic review reporting.
Since PRISMA’s original publication, the research community has seen numerous advances and evolution in processes and methodologies, not to mention putting a greater emphasis on sharing data, the need for faster, more transparent evidence, and an uptake in the use of automation tools to help expedite the systematic review process.
With all of these factors, it was time for PRISMA to get an update. That update has just been completed by a team of 26 contributors from eight countries. We spoke with Matt Page, lead author on the PRISMA 2020 Statement to learn more about the impetus for the update and some of the key changes relevant to review teams.
How the Current State of Research Influenced the PRISMA 2020 Statement?
While the original PRISMA statement made great strides to improve the transparency of reporting in systematic reviews, research advances and current data trends suggested that several modifications to the statement could better serve the review community and better reflect the current state of scientific research.
“We needed the original guidelines because of poor reporting observed across many sections of published reviews,” said Page. As the needs of researchers evolved, it became more evident that PRISMA would also need to evolve to meet them.
The PRISMA 2020 developers assessed 60 documents providing reporting guidance for systematic reviews and surveyed over 100 methodologists and journal editors to discern what exactly needed to be updated in the PRISMA statement.
The original PRISMA statement was a reflection of the current state of systematic review research. Now, 13 years later, the systematic review landscape has changed drastically. For example, there are new processes for synthesizing evidence, assessing risk of bias, registering reviews, and more. Today’s researcher also has access to new technology that either didn’t exist or was in its infancy in 2009.
I would encourage people who are working on a review now or preparing to undertake a new review to familiarize themselves with PRISMA 2020 as soon as possible.
In addition to meeting the needs of the ever-evolving research landscape, the PRISMA 2020 developers used this opportunity to improve the structure of the PRISMA checklist and PRISMA flow diagram. For example, where the original PRISMA statement included “double-barrelled” or “multi-pronged” questions, in the 2020 update, many of these items are broken down into individual elements, with the goal of making the checklist easier for reviewers to confirm if certain information is reported, and where it can be found in the systematic review.
“I would encourage people who are working on a review now or preparing to undertake a new review to familiarize themselves with PRISMA 2020 as soon as possible.”
- Matt Page
Senior Research Fellow
How Will the PRISMA 2020 Statement Impact Researchers?
The PRISMA 2020 statement is comprehensive, including several specific changes that frequent users of the original guideline should be aware of. Some of these PRISMA changes include recommendations to:
- Report on methods and results of an assessment of the certainty in the body of evidence for an outcome.
- Declare conflicts of interest of review authors to promote transparent disclosure.
- Specify whether data, analytic code or other materials are made publicly available and are easily accessible.
- Provide full search strategies for all databases searched used in the systematic review.
- Cite studies that might appear to meet the inclusion criteria, but which were excluded from the analysis.
“I would encourage people who are working on a review now or preparing to undertake a new review to familiarize themselves with PRISMA 2020 as soon as possible. Doing so should help them understand what types of information about their process they should be collecting now, so that they are ready to prepare a transparent account of their review at the write-up stage”, says Page.
2022 and Beyond
The PRISMA 2020 statement is an exciting milestone in the evolution of systematic reviews and transparency. Progress, growth, and evolution in the research community means better, faster evidence for everyone. According to Page, the PRISMA 2020 statement is designed to be somewhat agile. He doesn’t foresee the PRISMA update becoming obsolete or out-of-date soon, requiring another massive update. Instead, he predicts smaller PRISMA updates in the future as the research and systematic review landscape continues to evolve.
“There are a lot of people working in the systematic review space and bringing new ideas to it, which may result in new reporting guidance being necessary to add,” said Page. He also adds that the COVID-19 pandemic has resulted in a rapid uptake in systematic reviews. The need for fast, accurate evidence has also resulted in more researchers turning to automation in their reviews, something that PRISMA 2020 takes into consideration.
While the research process continues to evolve, guidelines like PRISMA will continue to enable more transparent reporting, resulting in better quality reviews, enhanced accuracy, and accessible evidence for all.
What Is the Purpose of the PRISMA Statement?
The PRISMA Statement acts as a roadmap to enable researchers, reviewers, and authors of systematic reviews or meta-analyses to follow minimum best practice standards. PRISMA comprises recommendations that facilitate comprehensive and transparent systematic review reporting, with a checklist of twenty-seven items that reviewers should include in their final documentation. These PRISMA standards help to ensure that systematic reviews get reported accurately, protecting the safety and integrity of the research.
As researchers gain access to more advanced data extraction automation tools, digital data sources, and evolving research methodologies, PRISMA has also adapted, with changes reflected in the updated PRISMA 2020 Statement. For example, the PRISMA statement now recommends that conflicts of interest, data accessibility, and excluded studies be examined and detailed within the review for full disclosure.
Who Should Use PRISMA in Systematic Reviews?
PRISMA is primarily designed to help scientific authors follow a structured approach to systematic reviews reporting but may also be relevant to editors and reviewers conducting peer reviews. The guidelines outlined within PRISMA apply to systematic review appraisal and reassessment projects, although the Statement is not designed as a quality evaluation tool.
Any professional developing a systematic review approach or writing a meta-analysis should complete the PRISMA checklist and include this with their work–this requirement is a prerequisite for most scientific and medical journals.
What Is the PRISMA Checklist For?
The PRISMA 2020 Statement includes an updated checklist, which contains the same count of twenty-seven items to be included within every systematic review. Reviewers can progress through the PRISMA checklist and indicate when each item has been completed in their systematic review.
Some PRISMA checklist items have been reworded or expanded to ensure a review meets changing standards in assessing certainty, disclosing relevant factors, and using automated data extraction tools.
2020 Updates to the PRISMA Checklist
Adjustments to the PRISMA Statement introduced in the 2020 revision include:
- The Abstract Reporting Checklist has been adjusted to the main guideline rather than an extension.
- Within the Methods section, authors are advised to include detailed search strategies for each database used.
- Selection Process recommendations focus on detailing how the reviewer has retrieved and screened research articles and reports, with or without data extraction tools, and any collaborators or secondary reviewers that assisted with this search process.
- As part of the Methods and Results sections, reviewers should report the approaches used to assess certainty or conviction in the correctness or relevance of evidence used to arrive at an outcome.
- Reviewers should report any conflicts of interest that may have swayed their work, approach, conclusions, or data selection choices for the systematic review.
- Systematic reviews should indicate whether the data used is available to the public and where records are available for inspection if applicable.
How Do You Reference a PRISMA Statement?
The PRISMA Statement recommends that reviewers do not refer directly to the PRISMA site within their work but instead use a journal citation. Reviewers can cite either an original PRISMA Statement or an addendum or addition, such as the PRISMA Explanation and Elaboration document.
Because PRISMA assets are distributed under a Creative Commons license, these can be used in a body of work or reproduced work, as long as the reviewer provides the source and name of the original author.