The objective of this study is to develop an extension of the PRISMA 2020 statement for LSRs. The aim of this paper is to report the details of the protocol for that study.

Establishment of the executive committee

The executive committee members, who are the authors of this protocol, will lead, organize, and author this extension. The executive committee consists of individuals with various backgrounds, including systematic review methodologists, LSR authors, co-leads and authors of the PRISMA 2020 statement, publishers, clinicians, and practice guideline methodologists.

Identify the need for a guidance

As noted earlier, there are a number of aspects of LSRs that the guidance from the PRISMA 2020 statement does not address, or where we believe modification is needed. Furthermore, we are not aware of any reporting guidance for LSRs published outside of the PRISMA banner.

Review the literature

To identify possible items of the PRISMA 2020 checklist that need to be added or modified for the reporting of LSRs, we will make use of the cumulative information arising from five methodological studies examining aspects of LSRs, and led by members of the executive committee: •

Methodological survey of published LSR flow diagrams ⁴

This survey examined how authors of all LSRs published since 2014 until April 2021 reported the flow of studies through the different phases of the review for each update. We noted six different ways of reporting study flow, none of which are currently required in the PRISMA 2020 flow diagram.

Identify participants

We will identify representatives of different stakeholders groups, including the authors of PRISMA 2020; authors of published PRISMA extensions ^{11 – 18} ; editors of journals that have published LSRs; representatives of organizations that have published LSRs (e.g., Cochrane, Campbell); publishers and editors of preprint platforms; practice guideline developers (e.g., the World Health Organization); practice guideline end-users (e.g., health care professionals, patients); end-users of the PRISMA LSR extension (i.e., LSR authors); systematic review methodologists; statisticians; information specialists; and research funders.

We will invite one to three representatives for each type of stakeholder (listed above). We will aim to have adequate gender and geographic representation.

Develop the first draft of the extension

We will develop the first draft of the checklist extension based on the results of the background studies (see ‘Review of the literature’ section). Then, the executive committee members will complete a survey to propose the items of the 2020 PRISMA checklist that may be modified. They will also propose new items that may be added.

Survey stakeholders about the extension’s first draft

In preparation for this step, we will summarize the findings of the background studies (see ‘review of the literature’ section) and share them with stakeholders. Then, we will survey the stakeholders for their views on each of the items included in the draft extension of the PRISMA 2020 checklist. For each item currently included in the PRISMA 2020 checklist, we will present its wording, its explanation and elaboration, and possibly a suggestion on how the item may be modified for LSRs. Then, for each item, we will seek stakeholders’ views on whether the item should be kept without changes or modified. We will ask similar questions for new items proposed by the executive committee. In addition, we will ask stakeholders to propose additional items to include in the checklist. We will calculate descriptive statistics using frequencies and percentages of responses to each item.

Develop the second draft of the extension

We will use the results of the survey to develop a second draft of the extension. Similar to the development process used for the PRISMA 2020 checklist, we will consider that an item has reached consensus when one of its response options is selected by more than 66% of the stakeholders. ¹⁹ Items for which no consensus is reached will be considered for discussion at a consensus meeting.

Conduct an online consensus meeting

We will conduct an online meeting to try and reach consensus on the content of the LSR extension. We will electronically share the second draft of the extension ahead of the meeting. The meeting will be held via an online meeting platform with enough sessions to cover the tasks to be completed and to accommodate the different time zones of those attending. Members of the executive team will chair the meeting and take minutes.

During the consensus meeting, we will give short presentations on the background, rationale, the scope of the project, the results of the survey. We will discuss the proposed list of modifications to the checklist (any new items and modifications of existing items of the PRISMA 2020 statement), and to the PRISMA flow diagram.

We will prioritize items for discussion for which there is a lack of consensus. The discussion will revolve around the different arguments for inclusion or exclusion of a specific item with the aim of reaching consensus. If outstanding issues are not resolved (not discussed, consensus not reached), we will re-work them post-meeting and share them via email with the meeting attendees for their comments.

If time allows, we will discuss the strategy for writing the manuscript, task assignment, authorship, and ideas regarding piloting and knowledge translation.

Develop the guidance statement and explanatory document

Members of the executive committee will draft initial documents including (1) the modified PRISMA 2020 checklist for LSRs, (2) explanation and elaboration for each item, and (3) modified flow diagram. These initial documents will then be circulated to all members of the executive committee and to all meeting attendees for feedback and approval. We will seek their views on the layout, clarity of the terminology, and the comprehensiveness of the set of items covered. Any proposed revision arising from these comments will be assessed by the executive committee as to whether further changes are required.

Develop a publication strategy

We will publish the extension in an open-access, peer reviewed journal and upload a pre-print and the material which informed the extension (e.g., de-identified survey data) to the Open Science Framework repository.

Plan post- publication activities

We will post this extension on the PRISMA statement website and will develop an application that facilitates the development/creation of a PRISMA 2020 flow diagram for LSRs. We will encourage readers and users to submit any comments or feedback via the website.

We will welcome and support any initiative to translate the extension or any part of it to a different language. We will contact editors of journals that publish LSRs to inform them about the extension and to seek their endorsement. Specifically, we will encourage journal editors and publishers to raise awareness of the extension by referring to it in journal “Instructions to authors”, endorsing its use, advising editors and peer reviewers to evaluate the reporting of submitted LSRs against this extension, and making changes to journal policies to accommodate the extension.

Currently, we are reviewing the literature, identifying the participants, and developing the first draft of the extension.

The number of LSRs has substantially increased over time, and this is set to keep growing. Complete and accurate reporting of the methods and results of these reviews is necessary for readers to understand the findings, and identify any methodological weaknesses, that may compromise those findings. In this protocol we have outlined the steps we will take to develop a reporting extension to PRISMA 2020 specific to LSRs.

Conducting online meetings to try reach consensus might have some advantages and challenges. An advantage is that such meetings are more feasible and convenient for attendees with busy schedules and ensures equity, especially for those who do not have funding to attend in-person meetings. On the other hand, there are time zone challenges when participants are attending from around the globe. To address this, we will try to accommodate the attendees’ different time zones. A further challenge relates to technical issues associated with Internet connection or other software failures. To address these challenges, we will ask the attendees to secure an alternative to the primary Internet connection in case the latter fails. A further strength is that members of the executive committee have diverse backgrounds and expertise at all levels that will enrich and facilitate completion of the extension.

We anticipate that the PRISMA 2020 extension for LSRs will benefit LSR authors, editors, and peer reviewers of LSRs, and different users of LSRs, including guideline developers, policy makers, healthcare providers, patients, and other stakeholders. We hope that implementation of the reporting guidance will lead to more transparent, complete, and accurate accounts of LSRs, thus providing the necessary synthesized evidence to underpin healthcare decisions.

No data are associated with this article.