What evidence syntheses reveal about PROSPERO, INPLASY, OSF, the Research Registry, and protocols.io: a meta-research study

Authors

• Raissa Tabosa Ferreira, Universidade de Brasília
• Manuela Queiroz Reis, Universidade de Brasília
• Maria Heloísa Pignataro Lange, Universidade de Brasília
• Maycon Willian Fontes da Costa, Universidade de Brasília
• Giovanna Kettlen Mendes Silva, Universidade de Brasília
• Anne Beatriz Oliveira Lemos, Universidade de Brasília
• Douglas Raphael Lela Dias, Universidade de Brasília
• Maria de Lourdes Santos Viana, Universidade de Brasília
• Ana Luiza Oliveira dos Santos, Universidade de Brasília
• Ana Beatriz Maia Fernandes, Universidade de Brasília
• Manuella Rocha Boaventura Pinheiro, Universidade de Brasília
• Clarice Wanderley de Sousa, Universidade de Brasília
• Kevin Henrique Azevedo Duarte, Universidade de Brasília
• Gustavo Vicentis de Oliveira Fernandes, Missouri School of Dentistry and Oral Health
• Carlos Marcelo da Silva Figueredo, Griffith University
• Mario Vianna Vettore, Aarhus Universitet
• Marcelo Marotta Araujo, Universidade Estadual Paulista "Júlio de Mesquita Filho"
• Fabio Gamboa Ritto, University of Oklahoma College of Dentistry
• João Vitor dos Santos Canellas, Universidade de Brasília

Document Type

Article

Publication Title

Frontiers in Research Metrics and Analytics

Abstract

Background: This meta-research study examined how protocol registration information is reported in evidence syntheses published from 2020 to 2025 and registered in PROSPERO, INPLASY, OSF, the Research Registry, or protocols.io. Methods: We analyzed 4,750 studies covering various evidence synthesis types. Data were collected on registry use, reporting transparency, and accessibility features. Statistical comparisons included effect sizes with 95% confidence intervals. Results: PROSPERO remained the most widely used, with registrations from 70 countries. Among studies registered on non-PROSPERO platforms, more than 90% were found in INPLASY and OSF. Compared with PROSPERO, both registries demonstrated stronger reporting practices, with higher protocol status updates in INPLASY and more hyperlinks in OSF. However, a hyperlink did not always ensure public availability, as several OSF protocols required author authorization. Protocols in PROSPERO were associated with multiple publishers. In contrast, INPLASY protocols were more frequently linked to open-access journals, particularly those published by Frontiers and MDPI. Conclusion: Although PROSPERO remains the reference registry, INPLASY and OSF are playing an increasingly important role in promoting openness and accessibility. Researchers are encouraged to search multiple registries, especially PROSPERO, INPLASY, and OSF, before starting a new study to minimize the duplication of efforts. Systematic review registration: https://www.doi.org/10.37766/inplasy2025.6.0114, identifier INPLASY202560114.

DOI

10.3389/frma.2026.1738112

Publication Date

1-1-2026

Recommended Citation

Ferreira, Raissa Tabosa; Reis, Manuela Queiroz; Lange, Maria Heloísa Pignataro; da Costa, Maycon Willian Fontes; Silva, Giovanna Kettlen Mendes; Lemos, Anne Beatriz Oliveira; Dias, Douglas Raphael Lela; Viana, Maria de Lourdes Santos; dos Santos, Ana Luiza Oliveira; Fernandes, Ana Beatriz Maia; Pinheiro, Manuella Rocha Boaventura; de Sousa, Clarice Wanderley; Duarte, Kevin Henrique Azevedo; Fernandes, Gustavo Vicentis de Oliveira; Figueredo, Carlos Marcelo da Silva; Vettore, Mario Vianna; Araujo, Marcelo Marotta; Ritto, Fabio Gamboa; and Canellas, João Vitor dos Santos, "What evidence syntheses reveal about PROSPERO, INPLASY, OSF, the Research Registry, and protocols.io: a meta-research study" (2026). MOSDOH Faculty Publications. 211.
https://scholarworks.atsu.edu/mosdoh-faculty/211