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PROSPERO

PROSPERO, the International Prospective Register of Systematic Reviews, is a free, open-access online database that enables the prospective registration of systematic review protocols in fields such as health and social care, welfare, public health, international development, and social sciences.^[1] Launched in February 2011, it serves as a central repository to document planned reviews before data extraction begins, ensuring that protocols are publicly available for verification against final publications. Operated by the Centre for Reviews and Dissemination (CRD) at the University of York in the United Kingdom, PROSPERO was developed to address key challenges in systematic review methodology, including unintended duplication of efforts and selective reporting of outcomes. By requiring detailed protocol submissions—including review questions, search strategies, eligibility criteria, and planned analyses— the registry facilitates collaboration among researchers and allows stakeholders to identify ongoing work in similar areas. Registration is voluntary but encouraged by guidelines from organizations like the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) group, with reviews ineligible if they have already completed data extraction. As of November 2025, PROSPERO has over 388,000 registrations, demonstrating its growing adoption as a tool for enhancing research transparency and reproducibility, though it primarily accepts protocols in human health-related topics and excludes those solely on animal studies or diagnostic accuracy without health outcomes.^[1] The platform's search functionality allows users to query by title, author, or keywords, supporting evidence synthesis in an era of increasing review volume, while ongoing evaluations highlight its role in minimizing bias without imposing editorial approval on registered protocols.^[2]

Background

Systematic Reviews and Protocol Registration

A systematic review is a rigorous synthesis of empirical evidence that addresses a specific research question by collating all relevant studies meeting predefined eligibility criteria, using explicit and reproducible methods to minimize bias and ensure transparency. Key characteristics include a clearly stated set of objectives, systematic identification of studies through comprehensive searches, critical appraisal of included studies for validity and risk of bias, and a synthesis of findings, often quantitative via meta-analysis, to provide reliable estimates of effects. These features distinguish systematic reviews from narrative or selective literature summaries by emphasizing comprehensiveness and methodological rigor to reduce subjectivity.^[3] The process of conducting a systematic review typically unfolds in three main stages: planning, execution, and reporting. In the planning stage, reviewers develop a protocol that outlines the research question, eligibility criteria, search strategy, and methods for data synthesis to establish a blueprint before any data collection begins.^[3] The execution stage involves implementing the protocol through comprehensive literature searching across databases and other sources, screening studies for inclusion, extracting relevant data, and assessing risk of bias in the selected studies.^[4] Finally, the reporting stage entails synthesizing the evidence—often via meta-analysis—and presenting findings in a structured format, such as adhering to PRISMA guidelines, to facilitate interpretation and application. Protocol registration plays a crucial role in systematic reviews by prospectively documenting the planned methods prior to execution, thereby enhancing transparency and accountability in the research process.^[5] This practice helps prevent selective reporting of outcomes, where only favorable results are highlighted, and reduces the risk of post-hoc methodological changes that could introduce bias.^[6] Additionally, registration allows researchers to identify ongoing reviews, avoiding duplication of effort and promoting efficient use of resources across the scientific community.^[7] The concept of protocol registration in research evolved in the early 2000s, driven by growing recognition of biases in unreported studies and selective outcomes, with organizations like the Cochrane Collaboration advocating for prospective documentation to improve review quality.^[8] By the early 2000s, the Cochrane Collaboration had begun publishing protocols for systematic reviews in the Cochrane Library, which helped ensure adherence to predefined plans and influenced broader practices; a 2002 study compared planned and executed methods in these protocols.^[9] Without protocol registration, systematic reviews face significant challenges, including outcome reporting bias, where discrepancies between planned and reported results distort evidence synthesis.^[8] Post-hoc alterations to methods, such as changing inclusion criteria after seeing results, can further undermine reproducibility and validity.^[6] Moreover, the lack of visibility into ongoing work leads to inefficient resource allocation through duplicated reviews on the same topic.^[5] These issues highlight the foundational need for tools like PROSPERO to address such gaps in the review process.^[10]

Need for a Prospective Registry

Prior to the establishment of centralized registries, systematic review practices in the 2000s were plagued by significant duplication, with analyses revealing overlap in up to 31% of overviews of reviews published between 2000 and 2018, many originating from uncoordinated ongoing efforts during that earlier period.^[11] This lack of coordination resulted in redundant research on similar topics, exacerbating inefficiencies in evidence synthesis across health fields. Without mechanisms to track planned reviews, researchers often unknowingly replicated work, leading to fragmented knowledge bases and missed opportunities for collaboration. Reporting biases further compounded these issues, as meta-epidemiological studies from the late 2000s and early 2010s demonstrated high levels of missing outcome data and suspected selective reporting in trials included in systematic reviews, particularly affecting unpublished protocols where outcomes were altered or omitted post-hoc.^[12] For instance, in a cohort of Cochrane systematic reviews, 34% included at least one trial with high suspicion of such bias, distorting meta-analyses and overestimating treatment effects in up to 23% of cases.^[12] These biases undermined the reliability of reviews, as incomplete protocol documentation hindered verification of prespecified outcomes. Existing systems for protocol sharing were limited, relying on informal methods such as publication in the Cochrane Library or journal supplements, which provided incomplete accessibility and posed verification challenges for non-Cochrane reviews.^[9] This fragmented approach made it difficult to identify ongoing work or ensure transparency, often resulting in changes to review methods after results were known, thereby introducing bias.^[9] In response, leading journals issued calls for action in 2010–2011, with PLoS Medicine endorsing mandatory prospective registration of systematic review protocols to prevent duplication and enhance transparency, akin to requirements for clinical trials on platforms like ClinicalTrials.gov.^[13] Similarly, international consultations supported by BMJ and others advocated for standardized datasets to facilitate registration, aiming to align systematic reviews with rigorous trial standards.^[14] These endorsements highlighted the economic and ethical implications, including wasted resources—estimated at over $140,000 per duplicated review, potentially totaling millions annually—and delays in evidence synthesis that hindered policy decisions and patient care.^[15]

Overview

Purpose and Objectives

PROSPERO serves as an international prospective register for protocols of systematic reviews in health and social care, with primary objectives centered on enhancing the reliability of these reviews. By enabling the timestamped registration of protocols prior to the commencement of data collection, it promotes transparency in the research process, allowing researchers to verify the pre-specification of methods and outcomes. This pre-commitment mechanism aims to minimize reporting bias, such as selective outcome reporting, where results are emphasized or omitted based on their favorability. Additionally, the registry facilitates searches for ongoing reviews, thereby reducing unplanned duplication of effort and resources across the research community.^[16] Secondary goals of PROSPERO include fostering collaboration among researchers by providing a public platform for identifying complementary work and potential partnerships. It supports funders, policymakers, and research commissioners in mapping the landscape of planned reviews, aiding in the prioritization of evidence needs and resource allocation. The registry also encourages adherence to established reporting standards, particularly the PRISMA-P guidelines for systematic review protocols, which emphasize comprehensive documentation of methods to ensure reproducibility. These aims align with broader open science principles, as evidenced by endorsements from key stakeholders, including a 2011 editorial in PLoS Medicine advocating for protocol registration to uphold best practices in systematic reviews, and support from the EQUATOR Network for transparent reporting initiatives.^[16]^[13] Target outcomes of PROSPERO include improved methodological rigor through enforced pre-planning, faster identification of evidence gaps by highlighting under-reviewed topics, and potentially higher publication rates for completed reviews due to reduced abandonment from duplication awareness. Organizations such as Cochrane and the Campbell Collaboration have endorsed the registry, recognizing its role in advancing evidence synthesis integrity.^[16] PROSPERO is explicitly not a peer-review service, nor does it guarantee the quality or feasibility of registered reviews; it functions solely as a neutral, publicly accessible repository for prospective protocols.^[16]

Scope and Eligibility Criteria

PROSPERO was initially launched in 2011 with a scope limited to systematic reviews in health and social care that assess health-related outcomes, such as those evaluating interventions, diagnostic strategies, prognostic factors, or etiologies in physical or mental health contexts.^[16] Following expansions, the current scope encompasses systematic reviews in broader fields including criminology, social care, education, and international development, provided they address health-related or social outcomes through quantitative or mixed-methods synthesis.^[1] Eligibility for registration requires that reviews be prospective—meaning no data extraction has been completed and no publications have occurred—employ explicit systematic search and synthesis methods, and feature a clearly defined research question with specified outcomes; geographic origin imposes no restrictions. Registration also requires an Open Researcher and Contributor ID (ORCID) for the submitting researcher.^[16]^[1] Ineligible submissions include rapid reviews, overviews of reviews unless they clearly define primary outcomes and meet synthesis criteria, those lacking primary outcomes, pure qualitative syntheses without broader outcome integration, scoping reviews, and literature reviews absent quantitative or qualitative synthesis; common rejections involve non-systematic narrative reviews that fail to outline rigorous methods.^[17]^[18] The expansions to eligible fields foster greater inclusion of social science applications while reinforcing emphasis on intervention, diagnostic, prognostic, and etiology-focused reviews to ensure methodological rigor and relevance to evidence-based decision-making.^[1]

History

Development and Launch

PROSPERO was developed by the Centre for Reviews and Dissemination (CRD) at the University of York in the United Kingdom, initiating the project in 2010 following international expert consultations to establish a minimum dataset for systematic review protocols. These consultations involved an international advisory group and emphasized the need for prospective registration to enhance transparency in systematic reviews, drawing parallels to established practices in clinical trial registration.^[14] The registry was officially launched on February 22, 2011, by Lord Howe, the UK Health Minister (Frederick Curzon, 7th Earl Howe), at an event highlighting its role in promoting open science and reducing reporting bias in health research.^[19] Initial funding came from the National Institute for Health Research (NIHR), supporting the creation of an open-access, web-based platform hosted by CRD to facilitate global accessibility without subscription barriers.^[20]^[16] This launch occurred amid a broader push for research transparency, building on initiatives like the 2005 extensions to the CONSORT statement for randomized trials, which underscored the importance of protocol registration to minimize duplication and bias. By October 2011, PROSPERO had registered 200 protocols from reviewers in 26 countries, spanning diverse health topics such as oncology, mental health, and diagnostic strategies.^[16]

Expansion and Key Milestones

Since its launch in 2011, PROSPERO has experienced substantial growth in registrations, reflecting increasing adoption by the research community for prospective protocol registration. By October 2017, the database contained 26,535 registered systematic reviews, marking a tenfold increase from 63 monthly registrations in 2012 to 800 per month by 2017.^[21] This expansion continued, with the number surpassing 106,828 records by February 2021, driven by heightened awareness of the benefits of registration in reducing duplication and bias.^[22] Growth accelerated further, exceeding 300,000 records by early 2025 and surpassing 388,000 by November 2025, underscoring PROSPERO's role as a central resource for evidence synthesis transparency.^[23]^[1] A key early milestone was the 2013 partnership with the Cochrane Collaboration, which enabled automated uploads of protocols for Cochrane intervention and diagnostic test accuracy reviews directly into PROSPERO.^[24] This integration enhanced interoperability between the two platforms, allowing Cochrane protocols to benefit from PROSPERO's public registry while broadening the database's coverage of high-quality systematic reviews. In terms of scope, PROSPERO originally focused on health-related outcomes but expanded in 2021 to explicitly include non-health fields such as criminology and education, in response to stakeholder feedback seeking greater applicability across disciplines like social care, welfare, public health, crime, justice, and international development.^[25] This broadening aligned with evolving needs for prospective registration in interdisciplinary evidence synthesis. Concurrently, updates in 2020 addressed the surge in COVID-19-related submissions by prioritizing accelerated reviews on pandemic topics, implementing streamlined processes to facilitate rapid registration of protocols examining interventions, risk factors, and outcomes associated with the virus. Technological advancements supported this expansion, including the introduction of advanced search filters in 2015 to improve user navigation and retrieval of specific protocols. In 2018, API access was added to enable seamless integration with external tools and databases, facilitating automated data exchange and broader accessibility for researchers and institutions. By 2020, a mobile-friendly interface was implemented, enhancing usability across devices and accommodating the increased remote access during the pandemic. In early 2025, a new version of the platform was launched, featuring automated eligibility checks, duplication detection, and improved processing to handle growing submission volumes.^[23] Policy evolutions further refined operations, with mandatory fields for risk-of-bias assessments introduced in 2014 as part of PROSPERO's 22 required protocol elements, ensuring comprehensive methodological transparency from the outset.^[26] To manage high submission volumes and backlogs exacerbated by the 2020 pandemic, temporary measures were enacted, including the suspension of full eligibility screening for non-urgent registrations pending over 30 days, allowing direct publication to mitigate delays and maintain timeliness without compromising core standards.^[27]

Operations

Registration Process

The registration process for PROSPERO begins with users creating a free account on the official website, which requires an Open Researcher and Contributor ID (ORCID) to facilitate identification and linkage across research outputs.^[1] A member of the review team, typically the corresponding author, then completes an online form detailing the proposed systematic review. The form includes 28 mandatory fields and 12 optional ones, covering administrative information such as the review title, anticipated start and completion dates, review team affiliations and contact details, funding sources, and declarations of ethical considerations and conflicts of interest.^[22] Methodological details are also required, including the research question structured in PICO (Population, Intervention, Comparator, Outcome) format, eligibility criteria for study inclusion and exclusion, planned search strategy with data sources (e.g., MEDLINE, Embase, Cochrane Central Register of Controlled Trials), methods for data extraction and risk of bias assessment, and planned analyses such as meta-analysis or narrative synthesis.^[16] Optional elements may include uploading a full protocol PDF and additional secondary outcomes. No registration fee is charged, and the process is designed to be completed prospectively, before data extraction begins, to ensure eligibility.^[28] As the form is filled, the PROSPERO system automatically identifies and flags any similar previously registered reviews to help avoid duplication.^[28] Users can save progress and edit the entry multiple times before final submission. Upon completion, all named review team members must review and approve the content, after which the record undergoes automated checking for completeness and basic eligibility. Since the platform's update in February 2025, qualifying submissions are published automatically without manual review by the Centre for Reviews and Dissemination (CRD) team, significantly reducing processing times compared to prior versions that involved screening within 5-10 working days.^[29] If issues are detected during automated checks, users are prompted to revise and resubmit. Ineligible submissions, such as those for scoping reviews, literature reviews without health-related outcomes, or retrospective registrations (e.g., after screening or data extraction has started), are not published.^[16] Once published, each record receives a unique identifier in the format CRD4202XXXXXX, which serves as a permanent reference and can be cited in publications.^[1] Registrants can update the record at any stage to reflect amendments, providing justification for changes, or mark it as completed (with publication details), ongoing, abandoned, or discontinued. The platform sends periodic reminders to maintain record currency, promoting transparency throughout the review lifecycle.^[22] Common pitfalls in the registration process include incomplete specification of PICO elements, such as vaguely defined outcomes or populations, failure to list at least two electronic databases in the search strategy, or omitting conflict of interest disclosures, which can delay publication until addressed.^[16] Additionally, attempting to register reviews outside PROSPERO's scope, like diagnostic test accuracy studies without a health outcome focus or animal-only studies, often results in non-publication after automated flagging.^[30] Users are encouraged to consult the eligibility criteria outlined in the platform's help section prior to submission to minimize revisions.^[28]

Database Features and Management

PROSPERO offers robust search functionality to facilitate discovery of registered systematic review protocols. Users can perform free-text searches across all fields or apply advanced filters by topic keywords, review status (e.g., ongoing, completed, or withdrawn), country of the review team, and registration date range. Search results can be exported in formats such as RIS for integration with bibliographic software like EndNote and CSV for tabular analysis in tools like Excel, enabling efficient data handling and citation management.^[31]^[22]^[32] The database is hosted on secure servers at the University of York, benefiting from the institution's infrastructure including daily backups to safeguard against data loss and ensure operational continuity. PROSPERO maintains compliance with the UK General Data Protection Regulation (GDPR) through the University of York's data protection policies, which govern personal data processing. It also aligns with open data principles by granting free public access to all approved records upon publication, promoting transparency without embargo periods.^[33]^[34]^[1] Administrative oversight is provided by the Centre for Reviews and Dissemination (CRD) team at the University of York, which processes thousands of submissions monthly—reaching approximately 6,500 published records in November 2024 alone. The team performs annual audits to uphold data quality standards and utilizes automated duplication detection during registration to flag similar protocols, reducing redundant efforts and enhancing the registry's utility.^[23]^[28]^[35] Accessibility features emphasize openness and ease of use, with the database available without login requirements for browsing and viewing records since its inception. Registered authors access a secure login portal via email or ORCID to submit updates or amendments to their protocols. While primarily interface-limited to English, PROSPERO supports global users through its international scope, though full multilingual translation is not currently implemented.^[16]^[36] Sustainability is supported by ongoing funding from the National Institute for Health and Care Research (NIHR), which has sustained operations since the registry's development under the CRD at the University of York. This funding model ensures long-term maintenance, with the database hosting over 389,000 records as of November 2025.^[1]^[16]

Impact and Evaluation

Evidence of Benefits

A 2018 meta-epidemiological study of orthodontic systematic reviews published between 2012 and 2016 found that those registered in PROSPERO had an average 6.6% higher score on the AMSTAR methodological quality tool compared to unregistered reviews, after adjustment for potential confounders (95% CI: 1.0–12.3%).^[37] This association highlights how prospective registration promotes adherence to rigorous methodological standards from the outset. For instance, during the COVID-19 pandemic, duplicate registrations occurred in only 13% of analyzed records, underscoring the registry's role in minimizing unintended overlaps despite high submission volumes.^[38] This transparency benefit extends to broader impacts, including improved completion rates: early registrations (2011–2015) saw only 7% marked as completed, often leaving "zombie" records that clutter the database.^[39] Additionally, PROSPERO facilitates funder oversight, as exemplified by the UK's National Institute for Health Research (NIHR), which mandates registration for funded systematic reviews to track progress and ensure accountability.^[40] As of 2025, PROSPERO contains over 388,000 registrations, reflecting continued growth. Recent updates include an improved user interface and faster registration processing to enhance usability.^[1]^[41]

Criticisms and Limitations

Despite its contributions to transparency in systematic reviews, PROSPERO has faced criticism for the accumulation of "zombie reviews"—abandoned or unfinished registrations that remain in the database without updates, cluttering the registry and potentially misleading researchers about existing research gaps. A 2017 analysis revealed that only 7% of registrations from 2011 to 2015 were marked as completed or updated to published status, highlighting how these inactive entries distort perceptions of ongoing work and hinder efficient planning of new reviews. Inconsistencies between registered protocols and final published reviews represent another limitation, undermining the registry's goal of reducing bias. Additionally, PROSPERO's English-only interface for all registration fields creates accessibility barriers, excluding non-English-speaking researchers and contributing to higher rejection rates for submissions from diverse linguistic backgrounds prior to scope expansions in 2021.^[1] The registry's scope is limited to prospective protocols for systematic reviews of health and social care interventions, explicitly excluding scoping reviews, rapid reviews, and other formats.^[42] Enforcement challenges further compound these issues, as there is no mandatory requirement to link registrations to final publications or update statuses. Moreover, underuse persists in low- and middle-income countries, reflecting barriers like resource constraints and limited awareness in these regions.

Comparisons with Other Registries

PROSPERO, as an international registry for prospective systematic review protocols primarily focused on health and social care outcomes, differs from the Cochrane Library's protocol system in scope and rigor. While PROSPERO accepts registrations for a broad range of non-Cochrane reviews without requiring peer review, Cochrane protocols undergo editorial and peer-review processes before publication in the Cochrane Library, ensuring higher methodological scrutiny but limiting access to Cochrane-affiliated reviews.^[43] The 2013 integration, which enabled automated uploads of new Cochrane intervention and diagnostic test accuracy protocols to PROSPERO, helped minimize duplication and overlap between the two platforms.^[24] In comparison to INPLASY, launched in March 2020 as the International Platform of Registered Systematic Review and Meta-analysis Protocols, PROSPERO maintains a narrower scope by restricting registrations to reviews with clear relevance to human health outcomes, whereas INPLASY accommodates a wider variety, including scoping reviews, rapid reviews, and those in non-health fields like social sciences.^[44] INPLASY offers faster processing, with 94% of protocols published within 24 hours and all within 48 hours, contrasting PROSPERO's typical 5-10 day review period, which can extend to 30 days or more due to eligibility checks.^[45]^[2] By March 2023, PROSPERO had amassed over 150,000 registrations, far surpassing INPLASY's 4,658 protocols during the same period. As of November 2025, INPLASY has grown to over 8,480 registrations.^[1]^[44]^[46] PROSPERO shares a prospective registration emphasis with ClinicalTrials.gov but focuses exclusively on systematic review protocols rather than clinical trial data, omitting elements like intervention details or participant recruitment specific to trials.^[43] Unlike ClinicalTrials.gov, which mandates registration for certain trials under U.S. law with potential enforcement, PROSPERO operates without fees or legal requirements for reviews, relying on voluntary compliance to promote transparency.^[47] Both platforms are free to use, but PROSPERO's review-specific design avoids the trial-centric reporting obligations of ClinicalTrials.gov.^[1] From 2011 to 2020, PROSPERO captured 71% of protocol registrations among analyzed systematic reviews, establishing its dominance in health and social care domains, while alternatives like INPLASY serve niche areas such as social sciences.^[48] PROSPERO's strengths lie in its established trust, built over a decade of operation with advanced search functionalities and institutional backing, though it faces criticism for delays and scope limitations; in contrast, platforms like INPLASY provide greater flexibility in review types and processing speed.^[2] 2023 analyses conclude that no single registry fully covers the diverse needs of systematic review protocols worldwide, highlighting the complementary roles of these platforms.^[44]

Integration and Future Directions

PROSPERO's integration with established reporting guidelines enhances the standardization of systematic review protocols. The PRISMA-P guidelines, introduced in 2015, were specifically designed to align with PROSPERO's registration fields, allowing reviewers to transition seamlessly from registry entry to full protocol development by incorporating 17 essential items derived largely from PROSPERO's structure. This linkage promotes comprehensive protocol reporting and reduces inconsistencies in health-related systematic reviews.^[26] The platform also connects with workflow tools and international registries to support efficient review processes. For instance, PROSPERO registrations are commonly referenced in software like Covidence, a collaborative tool for screening and data extraction, enabling teams to verify protocol transparency during review execution. Additionally, PROSPERO was developed in collaboration with the World Health Organization's International Clinical Trials Registry Platform (ICTRP), drawing inspiration from trial registration standards to extend similar transparency measures to systematic reviews.^[7]^[49] Partnerships further amplify PROSPERO's reach within the open science ecosystem. Through affiliations with the EQUATOR Network, PROSPERO supports training and endorsement of reporting standards like PRISMA-P, fostering better protocol quality across global research communities. Data from PROSPERO registrations can be shared via platforms such as the Open Science Framework (OSF), which hosts protocols for broader discoverability and reuse, aligning with initiatives to enhance reproducibility in evidence synthesis.^[2] Looking ahead, PROSPERO continues to evolve amid growing demands for research transparency. With over 389,000 registered reviews as of November 2025, the platform faces increasing volumes that underscore the need for scalable infrastructure, potentially exceeding current capacities in the coming years.^[1] Future enhancements may include expanded support for diverse review types, building on its acceptance of rapid and umbrella reviews, to accommodate evolving methodological needs. Sustained funding from the National Institute for Health and Care Research (NIHR) remains central to PROSPERO's operations, though discussions on long-term viability highlight the importance of international collaborations to ensure accessibility. Policy advancements, such as recommendations in a 2023 Systematic Reviews survey, advocate for mandatory protocol registration to address barriers like administrative burdens and low uptake, thereby reducing duplication and bias in systematic reviews.^[1]^[50]

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Registration of systematic reviews in PROSPERO: 30000 records ...
Feb 20, 2018 · Since November 2013, new protocols for Cochrane intervention and diagnostic test accuracy SRs have been added to PROSPERO. While SRs ...
[47]
Study protocols | Cochrane Bias
PROSPERO is an international database containing protocols of systematic reviews with a health-related outcome. The database aims to reduce duplication of ...<|separator|>
[48]
The international platform of registered systematic review and meta ...
An important difference between PROSPERO and INPLASY is that PROSPERO does not accept systematic reviews without an outcome of clear relevance to human health.
[49]
INPLASY's guidance for registering systematic review protocols (2025)
Feb 9, 2025 · The review stage options are: 1) The review has not yet started; 2) Preliminary searches; 3) Piloting of the study selection process; 4) Formal ...
[50]
https://pmc.ncbi.nlm.nih.gov/articles/PMC10720136/
[51]
Protocol registration issues of systematic review and meta-analysis ...
Aug 25, 2020 · About 72.9% of the responders believed that protocol registration helped in avoiding unnecessary duplication of the reviews. However, 67.5% ...
[52]
An international prospective register of systematic review protocols
Background: Support has grown for the prospective registration of protocols for systematic reviews to encourage transparency in conduct and reporting.
[53]
Perspectives on systematic review protocol registration: a survey ...
Dec 14, 2023 · In a recent survey, SR authors listed several reasons for failing to register SR protocols, including the lack of awareness, non-mandatory ...