PRISMA-Ethics – Reporting Guideline for Systematic Reviews on Ethics Literature: development, explanations and examples

Systematic reviews (SR) are very well elaborated and established for synthesizing statistical information, for example of clinical studies, for determining whether a clinical intervention is effective. SRs are also becoming more and more popular in bioethics. However, the established approach of conducting and reporting a SR cannot be transferred to corresponding work on ethically sensible questions directly. This is because the object of investigation is not statistical information, but conceptual or normative information, e.g., ethical norms, principles, arguments or conclusions. There is some evidence that the quality of reporting of SRs on ethics literature could be improved in many regards. Although insufficient reporting is not a problem specific to bioethics, as poor study reports are also very common in SRs in e.g. medicine, authors of such SRs have the possibility to follow a reporting guideline – the well-established statement on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). For SRs on ethics literature, the PRISMA Statement can only be partially adopted due to the different type of information searched and analyzed.Thus, an international group of authors with years of experience in conducting and reviewing SRs on ethics literature adapted PRISMA for its application in the field of bioethics (“PRISMA-Ethics”). As methods stemming from qualitative research are often used for analysis and synthesis in SRs on ethics literature, also elements of the ENTREQ Guideline were incorporated in PRISMA-Ethics. The resulting reporting guideline has 22 items and is intended to provide authors of SRs on ethics literature with all information necessary for an adequate reporting of their SRs. It also allows readers, reviewers and journal editors critically evaluating the presented results and conclusions made. In this paper, we explain the rationale and give examples for each item. While we acknowledge heterogeneity on how to conduct a SR on ethics literature, we still maintain that there is a need for general reporting standards for improving transparency, understandability and verifiability of such SRs. We invite authors of SRs on ethics literature to test PRISMA-Ethics and to evaluate its usefulness. We hope for a critical discussion of the guideline and welcome its broad implementation.