Dietary recommendations should be based on scientific evidence, and ideally, systematic reviews (SRs) are conducted as part of the guideline development process. The usability of SRs for decision-making is primarily determined by the quality of the evidence from available primary studies, as well as the quality of the SRs themselves. A comprehensive SR protocol ensures high-quality implementation and minimises bias, while making these protocols publicly accessible, promotes transparency and prevents redundancy. The PROSPERO database offers valuable insights into planned methodologies. The aim of this study is to investigate the completeness of reporting in SR protocols for diet- or nutrition-related trials, determine how this has changed over time, and examine the publication of completed SRs by comparing their content with those described in the corresponding protocols.

We developed a systematic search strategy for PROSPERO to identify nutrition- or diet-related SR protocols registered at two different time points (2019 and 2024). Following a screening process to identify eligible protocols, relevant predefined data will be extracted. Subsequently, a structured search will be conducted to identify potential journal publications of the selected protocols, as well as publications describing the results of the SRs, from which relevant predefined data will be also extracted. The methodology of the published articles will be compared with the corresponding a priori protocols registered in PROSPERO. The PROSPERO records registered in 2019 will be compared with those registered in 2024. The results will be evaluated by descriptive statistics, the reporting completeness of PROSPERO records will be assessed based on Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P), the planned use of any approaches to assess certainty of evidence will be investigated, and the adherence of published SRs to the methodological details outlined in their corresponding PROSPERO entries will be examined.

Since both databases and publications used in this study are publicly available, ethical approval is not required. Results of the study will be submitted for publication in an international, peer-reviewed journal.

The present study has previously been registered with the Open Science Framework (https://osf.io/8fsx7).

Prehospital emergency care (PEC) requires rapid evidence-based decisions to maximise the effectiveness of care and to improve clinical outcomes. There are multiple challenges related to clinical research performed in the PEC setting. The aim of our study is to systematically review and assess the characteristics, quality of reporting, risk of bias and pragmatism in recent PEC trials, thereby identifying potential gaps and strengths that can guide the design of future prehospital studies.

We will systematically search databases MEDLINE, Embase and Cochrane CENTRAL to identify all randomised controlled trials conducted in the field of PEC and published in English language between 2010 and 2024. No restrictions will be made to the participants, interventions and outcomes. Risk of bias will be evaluated using the Cochrane Risk of Bias 2 tool. The level of pragmatism will be assessed using the Pragmatic-Explanatory Continuum Indicator Summary-2 score. Exploratory data analysis will be used to investigate and summarise main patterns. Differences in characteristics between PEC fields, study designs, publication year and associations between pragmatism levels, risk of bias and quality of reporting will be the primary focus.

There are no ethical concerns directly relevant to this review. This study has been previously registered with the Open Science Framework (osf.io/rzn9j). The manuscript will be submitted for publication to a relevant, peer-reviewed journal.