Systematic reviews: Separating fact from fiction

3D bioprinting of liver models: A systematic scoping review of methods, bioinks, and reporting quality

Background

Effective communication is crucial for broad acceptance and applicability of alternative methods in 3R biomedical research and preclinical testing. 3D bioprinting is used to construct intricate biological structures towards functional liver models, specifically engineered for deployment as alternative models in drug screening, toxicological investigations, and tissue engineering. Despite a growing number of reviews in this emerging field, a comprehensive study, systematically assessing practices and reporting quality for bioprinted liver models is missing.

Methods

In this systematic scoping review we systematically searched MEDLINE (Ovid), EMBASE (Ovid) and BioRxiv for studies published prior to June 2nd, 2022. We extracted data on methodological conduct, applied bioinks, the composition of the printed model, performed experiments and model applications. Records were screened for eligibility and data were extracted from included articles by two independent reviewers from a panel of seven domain experts specializing in bioprinting and liver biology. We used RAYYAN for the screening process and SyRF for data extraction. We used R for data analysis, and R and Graphpad PRISM for visualization.

Results

Through our systematic database search we identified 1042 records, from which 63 met the eligibility criteria for inclusion in this systematic scoping review. Our findings revealed that extrusion-based printing, in conjunction with bioinks composed of natural components, emerged as the predominant printing technique in the bioprinting of liver models. Notably, the HepG2 hepatoma cell line was the most frequently employed liver cell type, despite acknowledged limitations. Furthermore, 51% of the printed models featured co-cultures with non-parenchymal cells to enhance their complexity. The included studies offered a variety of techniques for characterizing these liver models, with their primary application predominantly focused on toxicity testing. Among the frequently analyzed liver markers, albumin and urea stood out. Additionally, Cytochrome P450 (CYP) isoforms, primarily CYP3A and CYP1A, were assessed, and select studies employed nuclear receptor agonists to induce CYP activity.

Conclusion

Our systematic scoping review offers an evidence-based overview and evaluation of the current state of research on bioprinted liver models, representing a promising and innovative technology for creating alternative organ models. We conducted a thorough examination of both the methodological and technical facets of model development and scrutinized the reporting quality within the realm of bioprinted liver models. This systematic scoping review can serve as a valuable template for systematically evaluating the progress of organ model development in various other domains. The transparently derived evidence presented here can provide essential support to the research community, facilitating the adaptation of technological advancements, the establishment of standards, and the enhancement of model robustness. This is particularly crucial as we work toward the long-term objective of establishing new approach methods as reliable alternatives to animal testing, with extensive and versatile applications.

An Evidence Synthesis of Covert Online Strategies Regarding Intimate Partner Violence

This systematic review synthesizes evidence of how people use the internet to deploy covert strategies around escaping from, or perpetrating, intimate partner violence (IPV). Online tools and services can facilitate individuals leaving abusive relationships, yet they can also act as a barrier to departure. They may also enable abusive behaviors. A comprehensive literature search of published and unpublished studies in electronic databases was conducted. Two researchers independently screened abstracts and full texts for study eligibility and evaluated the quality of included studies. The systematic review includes 22 studies (9 qualitative and 11 cross-sectional studies, a randomized control trial [RCT] and a nonrandomized study [NRS]) published between 2004 and 2017. Four covert behaviors linked to covert online strategies around IPV were identified: presence online, granular control, use of digital support tools and services, and stalking and surveillance. The same technology that provides individuals with easy access to information and supportive services related to IPV, such as digital devices, tools, and services, also enables perpetrators to monitor or harass their partners. This review takes a rigorous interdisciplinary approach to synthesizing knowledge on the covert strategies adopted by people in relation to IPV. It has particular relevance to practitioners who support survivors in increasing awareness of the role of digital technologies in IPV, to law enforcement agencies in identifying new forms of evidence of abuse, and in enabling designers of online/social media applications to take the needs and vulnerabilities of IPV survivors into account.

The rationale behind systematic reviews in clinical medicine: a conceptual framework

A systematic review (SR) is a type of review that uses a systematic method to provide a valid summary of existing literature addressing a clear and specific question. In clinical medicine (CM), the concept of SR is well recognized, especially after the introduction of evidence-based medicine; The SR of randomized clinical trials (RCTs) is considered the highest level of evidence on therapeutic effectiveness. Despite the popularity of the SRs and the increasing publication rate of SRs in CM and other healthcare literature, the concept has raised criticisms. Many of proper criticisms can be due to the deviation of some existing SRs from the original philosophy and well-established rationale behind the concept of SR. On the other hand, many criticisms are misconceptions about SRs which still exist even several decades after introducing the concept. This article presents a conceptual framework for clarifying the rationale behind SR in CM by providing the relevant concepts and their inter-relations, explaining how methodological standards of an SR and its rationale are connected, and discussing the rationale under the three-section: SR as a type of synthetic research, SR as a more informed and less biased review, and SR as an efficient scientific tool.

Advancing systematic-review methodology in exposure science for environmental health decision making

Systematic review (SR) is a rigorous methodology applied to synthesize and evaluate a body of scientific evidence to answer a research or policy question. Effective use of systematic-review methodology enables use of research evidence by decision makers. In addition, as reliance on systematic reviews increases, the required standards for quality of evidence enhances the policy relevance of research. Authoritative guidance has been developed for use of SR to evaluate evidence in the fields of medicine, social science, environmental epidemiology, toxicology, as well as ecology and evolutionary biology. In these fields, SR is typically used to evaluate a cause-effect relationship, such as the effect of an intervention, procedure, therapy, or exposure on an outcome. However, SR is emerging to be a useful methodology to transparently review and integrate evidence for a wider range of scientifically informed decisions and actions across disciplines. As SR is being used more broadly, there is growing consensus for developing resources, guidelines, ontologies, and technology to make SR more efficient and transparent, especially for handling large amounts of diverse data being generated across multiple scientific disciplines. In this article, we advocate for advancing SR methodology as a best practice in the field of exposure science to synthesize exposure evidence and enhance the value of exposure studies. We discuss available standards and tools that can be applied and extended by exposure scientists and highlight early examples of SRs being developed to address exposure research questions. Finally, we invite the exposure science community to engage in further development of standards and guidance to grow application of SR in this field and expand the opportunities for exposure science to inform environment and public health decision making.

Groundwater Management in Coastal Areas through Landscape Scale Planning: A Systematic Literature Review

Groundwater is one of the main resources for social-ecological systems. As part of the total water cycle and deeply connected with land use, groundwater management faces many challenges, especially in coastal areas. Landscape Scale Planning is an emerging approach for land use planning providing a framework for management based on evidence, given that landscapes have physical and information flows. Landscape Scale Planning embraces the following three dimensions: (i) the spatial dimension centres on the recognition of distinct landscape units; (ii) the temporal dimension entails past, current and future uses of a landscape; and (iii) the modification dimension involves the anthropogenic alterations that affected and will affect the landscape and its features along the spatial and temporal dimensions. Through a systematic literature review of 28 selected publications, this paper explores how groundwater management can be improved through a Landscape Scale Planning approach. The results show that Landscape Scale Planning can be applied as an integrative framework for groundwater management. Landscape units based on, but not limited to, geology, topography, cultural and socio-economic aspects can aid groundwater management to consider the differing spatial and temporal characteristics of the aquifer. Landscape Scale Planning can also favour the inclusion of land use change dynamics in groundwater management processes. To this end, the paper proposes guidelines for applying Landscape Scale Planning to inform groundwater management and consider land use changes.

On the role of review papers in the face of escalating publication rates - a case study of research on contaminants of emerging concern (CECs)

In the past few decades, there has been a dramatic increase in scientific publications dealing with contaminants of emerging concern (CECs) and the escalating publication rate makes it close to impossible for individual researchers to get an overview of the field. Assuring the relevance and quality of the research conducted in any research field is a crucially important task. The rapidly increasing publication rates imply that review papers will play a progressively more central role to that end. The aim of the present paper is to critically assess whether reviews dealing with contaminants of emerging concern (CECs) are effective vehicles for a healthy dialogue about methodological weaknesses, uncertainties, research gaps and the future direction of the field. We carried out a tiered content-analysis of CEC review papers. Relevant papers were identified through searches in Web of Science (Clarivate), leading to the identification of 6391 original research papers of which 193 are review papers. We find that the majority of CEC reviews are written as if they are comprehensive, even though this clearly is not the case. A minority (~20%) take a critical-analytical approach to the reviewing task and identify weaknesses and research gaps. The following widespread tendencies in CEC research papers are commonly noted as concerning: to equate removal of CECs to 'decreased concentrations in the effluent'; to focus on parent substances and not concern oneself with degradation products; to focus on most commonly studied substances rather than those of most concern; to not deal with the corollary of our inability to detect or assess the risk for all substances, and to give insufficient attention to uncertainties and the unknown. Several critical-analytical reviews are among the highest cited, which suggests that they have the potential to function as effective vehicles for a healthy dialogue on these topics. On the other hand, it would appear that the concerns expressed in these reviews have a limited impact, as the same concerns are repeated over time. This might be due to a tendency among review authors to express their concerns implicitly, instead of clearly spelling them out. Our study suggests that CEC reviews presently fail to provide adequate and reliable guidance regarding the relevance and quality of research in the field. We argue that the overwhelming number of publications in combination with a lack of quality criteria for review papers are reasons to this failure: it is well documented that choices made during the reviewing process have a major impact on the outcome of a review. These choices include: search engine; the criteria used to include or exclude papers; the criteria used to assess the quality of the data generated in the research papers included; the criteria used for the choice of substances/ organisms/ technologies reported on. The lack of transparent procedures makes it very difficult, if not impossible, to assess the quality of the findings presented or to put those findings in context. In this light, it is noteworthy that criteria for a good review paper are rarely spelled out by peer-reviewed journals or included in instructions on scientific writing. The dramatic increase in publications is a challenge for the entire research community, particularly for research fields that are expected to provide policy-relevant data. We argue that only when peer-reviewed journals start specifying quality criteria for review papers, can such papers be relied upon to provide adequate and strategic guidance on the development of CEC research. We anticipate that our findings and conclusions are valid for many other research fields.

A review of methods used for hazard identification and risk assessment of environmental hazards

BACKGROUND

Approximately one quarter of all deaths globally are attributed to living or working in an unhealthy environment, with household and ambient air pollution, along with exposures to ultraviolet radiation and chemicals amongst the leading causes. At present there are no international standards for assessing the risks of these environmental hazards. The use of heterogeneous methods to identify health risks from environmental hazards may reduce the level of confidence the public has in the conclusions that are made.

OBJECTIVES

To describe and compare the processes and methods used by national and international organisations that conduct hazard identification and/or risk assessment (HI/RA) of environmental hazards and to identify knowledge gaps to inform the development of future methods.

METHODS

We searched the websites of 19 organisations (ten national, five international and four World Health Organization (WHO) units) and extracted data from all relevant, publicly available resources which described the processes and methods used in HI/RA of environmental hazards. We contacted each organisation for any additional information.

RESULTS

Five organisations were excluded from further analysis: three made recommendations but did not conduct HI/RA; one used heterogenous methods across their reviews for HI; and one WHO unit did not have any published guidelines. Of the 14 organisations analysed, five (36%) describe the process for establishing the questions to be answered in the assessments. Only one (7%) organisation uses systematic review methods, although five (36%) state that they use such methods. Ten (71%) assess the scientific quality of the included studies, however only three (21%) use explicit criteria. Only three (21%) organisations assess the quality of the body of evidence using explicit criteria. Four (29%) organisations describe the process for making the final HI conclusions and three (38%) the final RA conclusions. Eight (57%) have a conflict of interest policy and seven (50%) organisations describe a process for managing them. The US Office of Health Assessment and Translation and the World Health Organisation meet the most criteria for describing their processes and methods.

CONCLUSIONS

The processes and methods used by organisations conducting HI/RA of environmental hazards are inconsistent. There is a need for empirically based tools and methods to be adopted for the evaluation and synthesis of evidence, and the formulation of conclusions across all organisations that conduct HI or RA. These tools and methods will lead to increased transparency, comparability and validity of the assessments.

The author's reply to N.R. Haddaway

In this reply we respond to the commentary of Dr. Haddaway addressed in searching for pitfalls in our systematic mapping exercise "Collating science-based evidence to inform public opinion on the environmental effects of marine drilling platforms in the Mediterranean Sea" recently published in Journal of Environmental Management (Mangano, M.C. and Sarà, G. 2017. Journal of Environmental Management 188: 195-202). We discussed each so called "pitfalls" and, in our opinion, the main cornerstones of systematic map - SM (repeatability, comprehensiveness, transparency, traceability, quality, generalizability) are safe guaranteeing the "gold standard" required by this technique. Where needed we explain our position in doing a "tailoring" of some steps, and we stressed the differences among our approach and a SM protocol. We also stressed the importance of our main message, to select the most rigorous approach (evidence-based), to create a credible, salient and effective knowledge baseline to inform end users and guarantee the creation of a solid science-policy nexus (here specifically we provided a final review product, an easy to follow up graphical evidence).

The benefits of systematic mapping to evidence-based environmental management

Reviews of evidence are a vital means of summarising growing bodies of research. Systematic reviews (SRs) aim to reduce bias and increase reliability when summarising high priority and controversial topics. Similar to SRs, systematic maps (SMs) were developed in social sciences to reliably catalogue evidence on a specific subject. Rather than providing answers to specific questions of impacts, SMs aim to produce searchable databases of studies, along with detailed descriptive information. These maps (consisting of a report, a database, and sometimes a geographical information system) can prove highly useful for research, policy and practice communities, by providing assessments of knowledge gaps (subjects requiring additional research), knowledge gluts (subjects where full SR is possible), and patterns across the research literature that promote best practice and direct research resources towards the highest quality research. Here, we introduce SMs in detail using three recent case studies that demonstrate their utility for research and decision-making.