Introduction

The value of every scientific study is not limited only to the results presented, but also to the way in which they are reported and documented. Systematic reviews and meta-analyses are fundamental tools in scientific progress, as they allow the collection, evaluation, and synthesis of data from multiple independent studies. However, to be effective, they require clear, transparent, and reproducible reporting of methodology and findings. Within this framework, PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) was developed as an internationally recognized guideline that aims to enhance the quality of reporting in such studies.

Definition and Purpose

The PRISMA Statement includes a 27-item checklist, along with a flow diagram that shows the exact number of studies identified, evaluated, and ultimately included in a systematic review or meta-analysis. Its main purpose is to help authors improve the transparency and completeness of their reporting, ensuring that the process is understandable and reproducible. At the same time, PRISMA can also be used as a basis for the evaluation of other types of research, such as interventions, diagnostic, or prognostic studies, while serving as a valuable tool for the critical appraisal of published systematic reviews.

Historical Development of PRISMA

The need for standardized reporting guidelines became evident as early as the 1980s, when studies highlighted weaknesses in the reporting of meta-analyses. Early attempts were made by researchers such as Mulrow and Sacks, but their reports were not sufficient. In 1996, the QUOROM Statement was developed, focusing on meta-analyses of randomized controlled trials, aiming to address this gap in reporting. However, in 2009, these guidelines underwent a major revision and were renamed PRISMA. This new form was enriched to reflect modern developments in the methodology of systematic reviews and to provide a more comprehensive framework for the international scientific community.

PRISMA Checklist

The PRISMA checklist consists of 27 items, organized into different sections of a scientific report. It begins with the title and abstract, emphasizing that the title must clearly state the nature of the study, while the abstract should be structured and include information on background, objectives, data sources, eligibility criteria, interventions, results, and conclusions. The introduction section explains the rationale of the study and clearly defines its objectives, framed within PICOS (Participants, Interventions, Comparisons, Outcomes, Study design).

The methodology section covers the study protocol and registration, eligibility criteria, information sources, search strategy, data collection process, and methods for assessing the risk of bias. Results are presented in detail and include the selection of studies, their characteristics, the assessment of risk of bias, the results of individual studies, and the synthesis of data through meta-analyses. Additional analyses, such as subgroup or sensitivity analyses, may also be included. The discussion section focuses on a summary of the main findings, the limitations identified at both study and review level, and the conclusions that can be drawn for future research. Finally, funding sources and the role of sponsors are reported to ensure transparency.

The Role of the Flow Diagram

A central feature of PRISMA is the flow diagram, which clearly illustrates the process of identifying and selecting studies. Through this, readers can understand how the initial number of articles retrieved in a search is narrowed down to the final set of studies included in the analysis. The flow diagram plays a key role in ensuring transparency and credibility of the process.

Importance and Applications

PRISMA is not a tool for measuring the quality of a review but rather a guideline for proper and complete reporting. It is used by authors, editors, and reviewers to ensure the validity and comparability of results. Additionally, it offers a standardized reporting framework that can be adapted to different research aims, such as etiological, epidemiological, diagnostic, or prognostic studies. Its use enhances the reliability of scientific knowledge and supports evidence-based decision-making in fields such as healthcare and policy-making.

Conclusions

In summary, PRISMA is an essential tool for improving the quality and transparency of systematic reviews and meta-analyses. Its application ensures the reliability of scientific knowledge, enhances the reproducibility of research, and provides a clear framework for reporting that is internationally accepted. In the future, further development of PRISMA is expected to integrate new scientific approaches and technological tools, ensuring that research continues to uphold the principles of transparency, validity, and progress in scientific inquiry.