PRISMA 2020 Replaces PRISMA 2009

At the end of March 2021, the PRISMA 2020 guideline update was simultaneously published in five journals, officially marking the replacement of the PRISMA 2009 with the updated PRISMA 2020 guideline:

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, Shamseer L, Tetzlaff JM, Akl EA, Brennan SE, Chou R, Glanville J, Grimshaw JM, Hróbjartsson A, Lalu MM, Li T, Loder EW, Mayo-Wilson E, McDonald S, McGuinness LA, Stewart LA, Thomas J, Tricco AC, Welch VA, Whiting P, Moher D. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews.

  • BMJ 2021 Mar 29;372:n71. doi: 10.1136/bmj.n71. PMID: 33782057; PMCID: PMC8005924.
  • Syst Rev. 2021 Mar 29;10(1):89. doi: 10.1186/s13643-021-01626-4. PMID: 33781348.
  • J Clin Epidemiol. 2021 Mar 17:S0895-4356(21)00073-1. doi: 10.1016/j.jclinepi.2021.03.001. PMID: 33789819.
  • Int J Surg. 2021 Apr;88:105906. doi: 10.1016/j.ijsu.2021.105906. Epub 2021 Mar 29.PMID: 33789826.
  • PLoS Med. 2021 Mar 29;18(3):e1003583. doi: 10.1371/journal.pmed.1003583. eCollection 2021 Mar. PMID: 33780438.

Published translations of this guideline into other languages are forthcoming.

For the most detailed description of the new PRISMA 2020 guideline, this accompanying “explanation and elaboration” article was also published:

  • Page MJ, Moher D, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, Shamseer L, Tetzlaff JM, Akl EA, Brennan SE, Chou R, Glanville J, Grimshaw JM, Hróbjartsson A, Lalu MM, Li T, Loder EW, Mayo-Wilson E, McDonald S, McGuinness LA, Stewart LA, Thomas J, Tricco AC, Welch VA, Whiting P, McKenzie JE. PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews. BMJ. 2021 Mar 29;372:n160. doi: 10.1136/bmj.n160. PMID: 33781993; PMCID: PMC8005925.

  • For details about the process that was used to develop the PRISMA 2020 update:

    Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, Shamseer L, Tetzlaff JM, Moher D. Updating guidance for reporting systematic reviews: development of the PRISMA 2020 statement. J Clin Epidemiol. 2021 Feb 9;134:103-112. doi: 10.1016/j.jclinepi.2021.02.003. Epub ahead of print. PMID: 33577987.

Noteworthy Changes in the PRISMA 2020 Update

Among the key PRISMA 2020 guideline changes are: more inclusive wording so that it’s more accommodating to other methods from different fields (ex., methods beyond randomized trials of health interventions); some of the categories have been broken down into more granular sub-items that are more explicit and provide more clarity about what exactly should be reported, some new items and sub-items have been introduced or expanded upon; and some of the items have been slightly re-ordered in the checklist.

The new PRISMA 2020 guideline is meant to reflect the changing reality of the current research climate. For example, now that more people are registering their protocols as is recommended by PRISMA, there is a sub-item added to address the clear reporting of potential protocol amendments. Also – in line with the open science movement, there are sub-items related to reporting about the availability of data and statistical code, etc. Furthermore, with automation tools starting to be considered for use in SRs, more explicit reporting in this area is also recommended, as well as the reporting of conflicts of interest of review authors, something which is becoming a more common requirement in all areas of scholarly publishing.

There also has been an obvious push towards greater transparency in the methods, with recommendations to include the full search strategies and number of results for all information resources searched (which is in accordance with the PRISMA-S extension also published this year), as well as to provide the full citations for all of the included studies and citations for the studies that were excluded at the full-text stage, with reasons.

This latest version of PRISMA also appears to recognize that often in SRs, the synthesis of the results includes the grouping or sub-grouping of studies for the analysis, which the guideline suggests should be better reported upon. PRISMA 2020 makes a more explicit request for the reporting of criteria and processes used to group studies. Related to this, PRISMA 2020 also encourages that the reporting of characteristics and risk of bias be handled not for all included studies as a whole but rather to be considered among sub-grouped studies contributing to each synthesis.

New Tools and Templates for PRISMA 2020

It should be noted that the PRISMA guidelines are recommendations and not every item in the checklist applies to every situation. (In fact, it is for that very reason that PRISMA extensions exist and should still be used in conjunction with PRISMA 2020 as not all of these have been perfectly harmonized as of yet.) As such – this guidance should be viewed as useful suggestions for improving the quality of reporting of a systematic review – keeping in mind, however, that not every item is always applicable and mandatory.

This spirit of flexibility is reflected in the increased template options made available on the PRISMA Statement website to accommodate different scenarios. Both the PRISMA 2020 Checklist and Flow Diagram template options are now available for viewing and downloading. In addition to the PDF and Word templates, Shiny App computer applications have also been created that can be used to more easily generate the completed checklist and flow diagram by inputting data.

To learn more, please view a recent presentation on PRISMA 2020 by the first author (Dr. Matthew Page, Monash University) responsible for the update and feel free to send us your questions at Ask Us at the MSK Library or to explore the Systematic Review Service LibGuide.

PRISMA-S Extension for Reporting Literature Searches

First introduced in 2009, the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement provides guidance to authors, journal editors, and readers about which informational elements should ideally be reported on and in what detail in a systematic review (SR) publication.

With the increase in systematic review publications over the last decade came more variance and variety within the SR/evidence synthesis study design, prompting the need for even more specialized guidance. Responding to this need, various special interest PRISMA groups worked to develop “extensions” to the PRISMA reporting guidelines, their number now reaching ten.

From the Equator Network:

PRISMA-Equity: Welch V, Petticrew M, Tugwell P, Moher D, O’Neill J, Waters E, White H; PRISMA-Equity Bellagio group. PRISMA-Equity 2012 Extension: Reporting Guidelines for Systematic Reviews with a Focus on Health Equity. PLoS Med. 2012;9(10):e1001333. PMID: 23222917

PRISMA-Abstracts: Beller EM, Glasziou PP, Altman DG, Hopewell S, Bastian H, Chalmers I, Gøtzsche PC, Lasserson T, Tovey D; PRISMA for Abstracts Group. PRISMA for Abstracts: Reporting Systematic Reviews in Journal and Conference Abstracts. PLoS Med. 2013;10(4):e1001419. PMID: 23585737

PRISMA-P: Moher D, Shamseer L, Clarke M, Ghersi D, Liberati A, Petticrew M, Shekelle P, Stewart LA. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 statement. Syst Rev. 2015;4(1):1. PMID: 25554246

PRISMA-IPD: Stewart LA, Clarke M, Rovers M, Riley RD, Simmonds M, Stewart G, Tierney JF; PRISMA-IPD Development Group. Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data: the PRISMA-IPD Statement. JAMA. 2015;313(16):1657-1665. PMID: 25919529

PRISMA extension for network meta-analyses: Hutton B, Salanti G, Caldwell DM, Chaimani A, Schmid CH, Cameron C, Ioannidis JP, Straus S, Thorlund K, Jansen JP, Mulrow C, Catalá-López F, Gøtzsche PC, Dickersin K, Boutron I, Altman DG, Moher D. The PRISMA Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-analyses of Health Care Interventions: Checklist and Explanations. Ann Intern Med. 2015;162(11):777-784. PMID: 26030634

PRISMA-harms: Zorzela L, Loke YK, Ioannidis JP, Golder S, Santaguida P, Altman DG, Moher D, Vohra S; PRISMA harms group. PRISMA harms checklist: improving harms reporting in systematic reviews. BMJ. 2016;352:i157. PMID: 26830668

PRISMA-CI: Guise JM, Butler ME, Chang C, Viswanathan M, Pigott T, Tugwell P; Complex Interventions Workgroup. AHRQ Series on Complex Intervention Systematic Reviews – Paper 6: PRISMA-CI Extension Statement & Checklist. J Clin Epidemiol. 2017. PMID: 28720516

PRISMA-DTA: McInnes MDF, Moher D, Thombs BD, McGrath TA, Bossuyt PM; and the PRISMA-DTA Group. Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies: The PRISMA-DTA Statement. JAMA. 2018;319(4):388-396. PMID: 29362800

PRISMA-ScR: Tricco AC, Lillie E, Zarin W, O’Brien KK, Colquhoun H, Levac D, Moher D, Peters MDJ, Horsley T, Weeks L, Hempel S, Akl EA, Chang C, McGowan J, Stewart L, Hartling L, Aldcroft A, Wilson MG, Garritty C, Lewin S, Godfrey CM, Macdonald MT, Langlois EV, Soares-Weiser K, Moriarty J, Clifford T, Tunçalp Ö, Straus SE. PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation. Ann Intern Med. 2018. PMID: 30178033

The latest PRISMA extension to be published in 2021 is the PRISMA-S extension which provides detailed guidance related to the preferred reporting of SR literature searches.

Rethlefsen ML, Kirtley S, Waffenschmidt S, Ayala AP, Moher D, Page MJ, Koffel JB; PRISMA-S Group. PRISMA-S: an extension to the PRISMA Statement for Reporting Literature Searches in Systematic Reviews. Syst Rev. 2021 Jan 26;10(1):39. doi: 10.1186/s13643-020-01542-z. PMID: 33499930; PMCID: PMC7839230.

To learn more about best practices regarding the literature search required – and its reporting – for a systematic review, be sure to check out the MSK Library’s Systematic Review Service LibGuide and/or consider attending an upcoming training class.

Demystifying the Systematic Review Process Workshop – Register Now!

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Learn more and please register to attend.

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