Modern standards for evidence-based decision making in clinical care and public health still rely solely on eminence-based input when it comes to normative ethical considerations. Manuals for clinical guideline development or health technology assessment (HTA) do not explain how to search, analyze, and synthesize relevant normative information in a systematic and transparent manner. In the scientific literature, however, systematic or semi-systematic reviews of ethics literature already exist, and scholarly debate on their opportunities and limitations has recently bloomed. A systematic review was performed of all existing systematic or semi-systematic reviews for normative ethics literature on medical topics. The study further assessed how these reviews report on their methods for search, selection, analysis, and synthesis of ethics literature. We identified 84 reviews published between 1997 and 2015 in 65 different journals and demonstrated an increasing publication rate for this type of review. While most reviews reported on different aspects of search and selection methods, reporting was much less explicit for aspects of analysis and synthesis methods: 31 % did not fulfill any criteria related to the reporting of analysis methods; for example, only 25 % of the reviews reported the ethical approach needed to analyze and synthesize normative information. While reviews of ethics literature are increasingly published, their reporting quality for analysis and synthesis of normative information should be improved. Guiding questions are: What was the applied ethical approach and technical procedure for identifying and extracting the relevant normative information units? What method and procedure was employed for synthesizing normative information? Experts and stakeholders from bioethics, HTA, guideline development, health care professionals, and patient organizations should work together to further develop this area of evidence-based health care.

(Semi-)systematic approaches to finding, analysing, and synthesising ethics literature on medical topics are still in their infancy. However, our recent systematic review showed that the rate of publication of such (semi-)systematic reviews has increased in the last two decades. This is not only true for reviews of empirical ethics literature, but also for reviews of normative ethics literature. In the latter case, there is currently little in the way of standards and guidance available. Therefore, the methods and reporting strategies of such reviews vary greatly. The purpose of the follow-up study we present was to obtain deeper methodological insight into the ways reviews of normative literature are actually conducted and to analyse the methods used. Our search in the PubMed, PhilPapers, and Google Scholar databases led to the identification of 183 reviews of ethics literature published between 1997 and 2015, of which 84 were identified as reviews of normative and mixed literature. Qualitative content analysis was used to extract and synthesise descriptions of search, selection, quality appraisal, analysis, and synthesis methods. We further assessed quantitatively how often certain methods (e.g. search strategies, data analysis procedures) were used by the reviews. The overall reporting quality varies among the analysed reviews and was generally poor even for major criteria regarding the search and selection of literature. For example, only 24 (29%) used a PRISMA flowchart. Also, only 55 (66%) reviews mentioned the information unit they sought to extract, and 12 (14%) stated an ethical approach as the theoretical basis for the analysis. Interpretable information on the synthesis method was given by 47 (60%); the most common methods applied were qualitative methods commonly used in social science research (83%). Reviews which fail to provide sufficient relevant information to readers have reduced methodological transparency regardless of actual methodological quality. In order to increase the internal validity (i.e. reproducibility) as well as the external validity (i.e. utility for the intended audience) of future reviews of normative literature, we suggest more accurate reporting regarding the goal of the review, the definition of the information unit, the ethical approach used, and technical aspects.

Background Systematic reviews (SR) are 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 cannot be transferred to SRs 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 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 poorly reported manuscripts are also very common in SRs in e.g. medicine, authors of such SRs have the possibility to follow existing reporting guidelines (e.g. PRISMA). Method An international group of authors with years of experience in conducting and reviewing SRs on ethics literature developed a reporting guideline for this specific area of application (RESERVE). The relevant background was provided by two reporting guidelines: PRISMA for systematic reviews and ENTREQ due to the importance of qualitative research approaches. Results RESERVE has 22 items and is intended to provide authors of SRs on ethics literature with all information necessary for an adequate reporting. 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. Conclusions 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. We invite authors of SRs on ethics literature to test and evaluate the usefulness of RESERVE. We hope for a critical discussion of the guideline and welcome its broad implementation.