Opening the review: perceptions and challenges of Open Science at CSP.

We analyze the perceptions and challenges related to open peer review (OPR) among contributors to Cadernos de Saúde Pública (CSP), in the context of Open Science practices. Seeking to understand how authors and reviewers perceive the adoption of this model, a cross-sectional survey was conducted between January and April 2025, with 1,280 respondents among nearly 3,000 Brazilian reviewers from the past three years. The questionnaire, developed on REDCap, consisted of 20 open- and closed-ended questions. Most respondents were female (59.4%), had a PhD degree (70.6%), and ties to public institutions (55.9%) by working in Collective Health research and teaching. As for OPR, while 23.1% were in favor of disclosing the names of authors and reviewers, 24.2% were opposed and 32.7% preferred intermediate answers, revealing caution. Respondents pointed out prior knowledge between authors and reviewers (52.7%) as the main source of discomfort, followed by fears about conflicts of interest and professional constraints. Results indicate that the CSP scientific community recognizes the benefits of OPR for transparency, but also underscore the need for clear guidelines, active editorial mediation, and participant protection. Model acceptance depends on its gradual and contextualized implementation, based on dialogue, training and recognition of review work. In conclusion, OPR can strengthen integrity and trust in science if accompanied by institutional responsibility and sensitivity to the specificities of Collective Health.