Ensuring patients benefit from the latest medical and technical advances remains a major challenge, with rational-linear and reductionist approaches to translating evidence into practice proving inefficient and ineffective. Complexity thinking, which emphasises interconnectedness and unpredictability, offers insights to inform evidence translation theories and strategies. Drawing on detailed insights into complex micro-systems, this research aimed to advance empirical and theoretical understanding of the reality of making and sustaining improvements in complex healthcare systems.Using analytical auto-ethnography, including documentary analysis and literature review, we assimilated learning from 5 years of observation of 22 evidence translation projects (UK). We used a grounded theory approach to develop substantive theory and a conceptual framework. Results were interpreted using complexity theory and ‘simple rules’ were identified reflecting the practical strategies that enhanced project progress.The framework for Successful Healthcare Improvement From Translating Evidence in complex systems (SHIFT-Evidence) positions the challenge of evidence translation within the dynamic context of the health system. SHIFT-Evidence is summarised by three strategic principles, namely (1) ‘act scientifically and pragmatically’ – knowledge of existing evidence needs to be combined with knowledge of the unique initial conditions of a system, and interventions need to adapt as the complex system responds and learning emerges about unpredictable effects; (2) ‘embrace complexity’ – evidence-based interventions only work if related practices and processes of care within the complex system are functional, and evidence-translation efforts need to identify and address any problems with usual care, recognising that this typically includes a range of interdependent parts of the system; and (3) ‘engage and empower’ – evidence translation and system navigation requires commitment and insights from staff and patients with experience of the local system, and changes need to align with their motivations and concerns. Twelve associated ‘simple rules’ are presented to provide actionable guidance to support evidence translation and improvement in complex systems.By recognising how agency, interconnectedness and unpredictability influences evidence translation in complex systems, SHIFT-Evidence provides a tool to guide practice and research. The ‘simple rules’ have potential to provide a common platform for academics, practitioners, patients and policymakers to collaborate when intervening to achieve improvements in healthcare.The online version of this article (10.1186/s12916-018-1076-9) contains supplementary material, which is available to authorized users. There is an urgent need to improve the delivery of high quality healthcare, including the need to improve patient safety and reduce harm –3, to enTo address these challenges, there is a need to bridge the gap between the production of research evidence and the consistent delivery of evidence-based care in routine practice –15. TherTraditional approaches to translating evidence into practice have taken a rational-linear approach (where knowledge is created by one set of experts and passed on to another set to be implemented) , 20. EvaIt is increasingly recognised that context matters; having an ‘appropriate’ context can support an intervention achieve its outcome . ApproacWhen designing intervention and implementation strategies, as well as when conducting rigorous evaluations, there is a tendency to reduce messy real world situations into the individual component parts in an attempt to determine the relationships between them. Doing so risks overlooking the complex and intricate patterns that emerge from their interactions.Complexity sciences provide an alternative approach to studying interventions in complex systems such as healthcare. Complexity science originated in physical chemistry as a ‘push-back’ against traditional reductionist approaches . Put simComplex systems are characterised as a dynamic network of agents acting in parallel, constantly reacting to what the other agents are doing, which in turn influences the behaviour of the network as a whole . The intOn the one hand, complex systems are highly dynamic, continually responding and adapting to internal and external stimuli. While, on the other, they can demonstrate inertia where embedded behaviours remain unchanged and even temporary perturbations or major structural alterations can fail to disrupt existing norms , 35. FroThe use of complexity science as a lens to understand healthcare systems is increasing . To dateThis study aims to develop a deeper explanation of evidence translation in healthcare using a complex systems lens, thereby contributing to both the fields of implementation science and complexity science. Drawing on detailed insights into complex micro-systems, this research advances empirical and theoretical understanding. A primary focus is given to understanding the implications of complexity theory with an objective of identifying a series of ‘simple rules’ about how to intervene in complex systems. The ‘simple rules’ aim to make complexity navigable (whilst recognising that it will never be simple), providing actionable guidance to both practice and research.The study was conducted using an analytical auto-ethnography and grounded theory approach Fig. . An analEmpirical data was collected through participant observation and document analysis of the National Institute of Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC), Northwest London (NWL) programme (UK), and 22 evidence translation projects  settings. We chose not to build exclusively on any existing theories as no single existing framework fit well with our experiences. Whilst several fields of study were relevant, no single frameworks brought together concepts from different fields, including knowledge translation, implementation, improvement and complexity.Results from the grounded theory analysis were interpreted through complex systems thinking , 34, 35.The NIHR established the CLAHRC programme in England to accelerate the translation of evidence into practice for the benefit of patients. Thirteen regional CLAHRC programmes were funded, each led by academic and healthcare partnerships and with autonomy to decide how they would approach ‘closing’ the translational gap –46.The CLAHRC NWL approach brought together healthcare staff, including clinical, managerial and support staff (hereafter referred to as ‘staff’) with patients, carers, family members and the wider community  and academic partners from a diverse range of disciplines  into project teams of 5–15 people to translate evidence into practice in their local micro-systems. Project teams used a suite of quality improvement tools and methods, including the model for improvement, action-effect diagrams and plan-do-study-act cycles, process mapping, statistical process control, stakeholder engagement, and patient and public involvement combined with iterative evaluation, to guide and support the implementation process –51.During the first 5 years of the CLAHRC NWL 2008–2013), 22 diverse topics considered of clinical importance were explored with 55 teams over four rounds of 18-month projects  is presented, introducing the three strategic principles of the framework, namely ‘act scientifically and pragmatically’, ‘embrace complexity’ and ‘engage and empower’, and the 12 ‘simple rules’.Secondly, there is a detailed presentation of the 12 ‘simple rules’ and accompanying substantive theory. The results demonstrate how the theory and rules emerged from the empirical data and how understanding is enhanced by application of a complex systems lens. The presentation of the rules and substantive theory is accompanied by two illustrative case examples from CLAHRC NWL projects to bring to life the practical reality of evidence translation.The theory of SHIFT-Evidence can be summarised as follows: to achieve successful improvements from evidence translation in healthcare, it is necessary to ‘act scientifically and pragmatically’ whilst ‘embracing the complexity’ of the setting in which change takes place and ‘engaging and empowering’ those responsible for and affected by the change.SHIFT-Evidence reflects the nature of work and breadth of effort required to translate evidence into complex systems. The findings revealed that attention and effort was often drawn away from the original project focus in directions that were not anticipated in advance, such as dependent issues relating to people, processes or structures, or to resolve existing problems with ‘usual care’. We established that failure to resolve these issues compromised the success of an intervention and diminished the ability to draw useful conclusions about the effectiveness of any intervention in a real-world setting. As such, the SHIFT-Evidence framework is conceptually based on the premise that the implementation of evidence-based interventions is not necessarily sufficient to achieve improvements in care, and that it is not possible to fully anticipate what changes will be required in any individual setting. In short, evidence translation and wider systems improvement are inextricably linked within complex systems.The accumulating data about the ‘daily realities’ of evidence translation and improvement required us to reconceptualise our understanding of the problem, and associated potential solutions. Our focus moved from evidence-based medicine and interventions, to focusing on the complexity of the systems within which we hoped to intervene. As such, literature relating to complex systems thinking grew in importance over time to become the primary lens by which we were able to make sense of our experiences  and local context-specific problem solving .We recognised the value of drawing insights from both perspectives. Effective improvement initiatives can benefit from drawing on a scientific knowledge base , and from making pragmatic adjustments in line with the opportunities and constraints of the actual setting for the change.“science of muddling through” in dynamic and evolving systems )Further research is required to examine how to effectively operationalise the SHIFT-Evidence ‘simple rules’ in practice . For exaSHIFT-Evidence is a unique framework with explanatory and predictive power grounded in the practical reality of evidence translation and improvement in healthcare. It advances thinking about how to intervene in complex systems, namely that, to achieve successful improvements from evidence translation in healthcare, it is necessary to ‘act scientifically and pragmatically’ whilst ‘embracing the complexity’ of the setting in which change takes place and ‘engaging and empowering’ those responsible for and affected by the change.A series of 12 action-orientated ‘simple rules’ are proposed to guide patients, practitioners, managers, policymakers and academics to intervene in complex systems. We propose that efforts to translate evidence into practice should be reconceptualised from focusing on simple relationships between interventions and outcomes to understanding the complex and nuanced work required when ‘intervening to achieve an improvement’. This better reflects the iterative and negotiated process required to test multiple interventions whilst noticing and responding to learning that emerges from the system over an extended period of time.This 18-month Collaboration for Leadership in Applied Health Research and Care (CLAHRC) North West London (NWL) project aimed to improve the timeliness and effectiveness of initial treatment of CAP during emergency hospital admission in order to improve patient outcomes and experience.Outline of problem (primarily explored during months 0–6)Evidence-based treatment for CAP was identified by the project team through a review of the 137 national guideline recommendations . Core reThe project leads believed all clinicians were aware of the treatment guidelines. Doctors agreed they knew the evidence and were confident that they and their clinical teams were delivering high-quality evidence-based care; thus, the project was considered unnecessary by many senior clinicians.A baseline audit of local practice showed 0% of patients received all evidence-based care elements, with compliance ranging from 13% to 90% for the individual elements. Further investigation revealed that junior doctors’ awareness of evidence was lower than expected, and that doctors, pharmacists and nurses needed to coordinate their work within the few first hours of hospital admission.Initial solutions (tested and implemented during months 7–18)An intervention was developed grouping the evidence-based care elements onto a single page paper-based ‘care bundle’ –108, desThe team collected weekly data on the extent to which each care element was delivered within 4 h. Following the initial implementation, low compliance persisted with < 5% of patients receiving all elements.To address poor uptake, the bundle was iterated 15 times over 12 months until the design and content was accepted by different clinical groups, the wording was clarified and the bundle deemed compatible with other usual care and documentation practices.During this initial phase it emerged that improvements needed to be addressed in the wider system, including updating oxygen and antibiotic prescribing policies and the lack of a process for ordering appropriate microbiological tests. Review of patient data also raised concerns about the accuracy of the initial diagnosis of CAP at first assessment.Four other sites across NWL engaged with the programme to adopt the CAP care bundle . New sites were motivated by data showing the care bundle improved delivery of evidence-based care but all spent several months appraising the evidence and intervention against their local experiences, knowledge, system and context before implementation commenced.Key learning about complexityCoordinated solutions were required that involved different professions working with senior executives to change policies and overcome barriers. These actions, combined with better staff education and awareness of CAP and the care bundle, improved delivery of timely care.Despite initial success, many factors continued to threaten sustained success on the original site. Regular review of compliance data enabled factors causing variation to be identified and addressed. For example, when measures showed a sudden drop in compliance, the original team investigated and identified junior doctors’ rotation as a contributing factor. They devised ways to improve junior doctor training and awareness at induction.Staff from different sites met together and learned that their challenges were common. Much of the knowledge shared was tacit, and passed on through discussions rather than written or formalised knowledge exchange.Other sites experienced similar factors to the original site that influenced their sustained success, including staff turnover and the emergence of conflicting organisational improvement priorities.OutcomesAlthough initially reluctant, rigorous weekly measurement allowed the team in the first site to track progress, identify potential improvements and, ultimately, to demonstrate success. Over 12 months, variation in delivery of the individual care elements reduced from 13–90% before the bundle to 74–92% afterwards, and overall compliance increased from 0% to 49% .Two sites achieved sustainable use of the bundle 1 year after the formal end of the project by integrating the bundle into the routine admission process. One site maintained measurement of CAP bundle compliance to continue monitoring and responding to variation in use and maintained high levels of compliance.The 18-monthCollaboration for Leadership in Applied Health Research and Care (CLAHRC) North West London (NWL) MM project aimed to implement an evidence-based post-discharge follow-up phone call , 111 to Outline of problem (primarily explored during months 0–6)The follow-up phone call intervention was intended to ensure patients understood their new medicines regimen. The project team expected the introduction of phone calls to be straightforward, but quickly discovered that they needed to address many related issues.Obtaining information about patients’ medication history to inform the follow-up phone call was a major problem, requiring triangulation of information from several sources after hospital admission. The availability of this information was recognised as a systemic problem which directly affected the ability to complete medicines reconciliation at discharge.Separate medication lists were maintained by up to four different professional groups for their own purpose  with little awareness of each other’s documentation practices. This silo-working increased the risk of medication errors. For example, a patient with arthritis was unable to open bottles with a child-proof top. The physiotherapist was aware of this, but the pharmacy was not and continued to dispense medications in inaccessible containers.Initial solutions (tested and implemented during months 7–12)Staff recognised that they would need to redesign the process, and renegotiate their roles to coordinate their work more effectively. A single agreed medicines reconciliation form was introduced, which allowed them to assess the quality of medicines reconciliation.Patients involved with the project challenged assumptions about relying on clinicians and organisations for this information. In a spin off project, clinical teams worked with patients to develop a patient-held ‘My Medications Passport’, which could act as an information source to support medicines reconciliation and help patients take greater ownership of their medication histories , 113.Key learning about complexityThe team had to negotiate with the executive team to secure the appropriate budget and permission for the changes in medicine reconciliation to take place. Delivering longer term changes required permission or support from people outside the team, including the education leads responsible for doctors’ induction.Aligning the project to organisational priorities took time and effort, and helped secure vital resources, including executive support, to further champion the work and permission for team members to be released to support the project.At the start of the project, medicines reconciliation had poor visibility within the hospital and was not an organisational priority. The team worked to increase its profile, identifying how the work related to key hospital concerns, including the importance of medicines reconciliation to admissions avoidance, how it linked to the safe and effective flow of patients through emergency care, and how it contributed cost-savings by avoiding inappropriate prescribing.Investigation into the causes of medication errors revealed several variables affecting the process, including the number of patients being admitted, the complexity of each patient’s condition, and the number and type of medications per patient. These variables were further influenced by staff working practices, including the time available to reconcile an individual patient’s medications. Variation in doctors’ performance prompted the team to improve teaching for junior doctors emphasising the importance of documenting medication changes using standardised procedures for recording and reconciling medicines. Junior doctors assumed someone else completed the medication documentation, so the team worked with them until it was accepted as a routine responsibility.OutcomesDuring the project, the error rate in medicines reconciliation reduced from 24% to an average of 11%. Week-to-week variation reduced from 0%–74% to 0%–32% ; at thisAdditional file 1:Project and programme publications: a list of CLAHRC NWL projects conducted between 2008 and 2013, and supporting publications from the CLAHRC NWL programme (DOCX 32 kb)Additional file 2:Research methods (DOCX 90 kb)Additional file 3:Example of coding and theory development (DOCX 14 kb)


The growing evidence base on the extent of and opportunities to reduce inequities in children's health and development still lacks the specificity to inform clear policy decisions. A new phase of research is needed that builds on contemporary directions in precision medicine to develop precision policy making; with the aim to redress child inequities. This would include identifying effective interventions and their ideal time point(s), duration, and intensity to maximize impact. Drawing on existing data sources and innovations in epidemiology and biostatistics would be key. The economic and social gains that could be achieved from reducing child inequities are immense. This includes designing and implementing policies across multiple portfolio areas that can change the social conditions that create inequities , as well as better utilizing existing social, health, and education infrastructure to redress them.7 To make inroads on health inequities, however, as well as considering programs and services aimed at the individual or micro level, there is a need to remain steadfastly focused on interventions and reforms that impact the institutions, social systems, and public policies that fundamentally drive health inequities.8At the same time, we are entering the age of precision and personalization. Precision medicine is based on specific evidence about how biological factors and their interactions with each other and treatment drive patient outcomes, so that treatment  can be adapted based on the unique profile of each patient. Precision public health approaches have focused on harnessing the power of Big Data, particularly genomic data, to inform targeted prevention approaches, including the prediction of individual risk.precision policy making. This would require specificity in the evidence about modifiable factors that redress child inequities; including evidence about their interactions with each other and existing interventions to create real world synergistic solutions. Equipped with this evidence, policy makers can choose the maximally effective public health, social, education, or health services strategy (or more likely series of strategies), target populations of children, developmental timing, and intensity and duration to reduce child inequities.4 Accelerating our research in this new direction will require wide ranging and trans-disciplinary collaborations, while maximizing the potential of existing evidence and data sources.To this end, we argue for the need to apply precision concepts to developing evidence that can enable 9 A clear implication of these findings was the need to create disincentives for employers to schedule work hours in a way that impacts on parenting capacities. This has since been actioned through legislation to address unpredictable work scheduling practices.9There are successful examples internationally where researchers have helped to inform precise policy decisions and action through evidence generation. For example, research from the United States found that children whose parents work unpredictable schedules or nonstandard hours exhibit poorer cognitive and behavioral outcomes, with disadvantaged and minority children being disproportionately impacted.10 Relative disadvantage is multidimensional, and manifests across the circumstances in which children, live, learn, and develop .11 Disadvantage can be experienced through four social determinants lenses ; children experience poorer outcomes for each increment of increasing disadvantage.Evidence to date shows starkly that inequities exist in all countries across children's physical health, social–emotional, and cognitive outcomes.children .4 Inequi12 optimizing the quality of parenting and the home learning environment,13 cash transfers,14 and mutually reinforcing combinations of strategies15—is the most effective and cost effective means of reducing the societal burden of health inequities.3 However, our current policy efforts in these areas are not closing these gaps.13 Governments continue to make large social service investments to remedy inequities later in life , rather than having a comprehensive policy and prevention funding response in the early years.3There is strong evidence to suggest that intervening in early childhood—such as through good quality preschool,2Evidence needed to inform the development of precision policy to redress child inequities includes identifying effective interventions to target specific populations of children, and the time point(s), duration and intensity, and intervention combinations that can maximize impact . The con12 in the Australian context there is a lack of evidence to inform with any level of specificity what approach is most effective.16 In the absence of this evidence, policy is being enacted regardless, such as decisions on the number of hours of preschool attendance to subsidize.Preschool is one example of where greater precision in the evidence is needed. Many governments see preschool as a major opportunity to reduce inequities. While current evidence suggests that preschool may be effective for certain populations,16 The development of such evidence would be informed by input from policy agencies and practitioners to ensure that the design reflects the current real-world considerations. Once findings were available, policy makers would inform interpretation and jointly consider where effort might be strategically and practically placed to effect recommendations for action.In contrast, precision policy responses could draw on specific evidence about what is most effective in terms of number of hours; curriculum/program elements most predictive of outcomes; teacher qualification; duration ; complementarity with other programs and supports; and approaches to engaging the most vulnerable families.18 Increasing data volume and variety in epidemiology and the expansion of “big data” have made possible the precision medicine and precision public health movements.18 The breadth of longitudinal and multilevel data available in existing cohorts, maximized through linkage with administrative data, can similarly enable researchers to generate policy relevant findings quickly and cost effectively. Well considered and comprehensive analyses of cohort data can provide robust evidence on opportunities and potential to reduce child inequities that can guide decision making, including where to target further evaluative intervention studies.19 Future cohorts may well provide the platform for within cohort trials in a more integrated approach to develop the evidence for precision thinking.Addressing the questions highlighted in 17 Notwithstanding these challenges, through choice of analytic methods it is possible to use cohort data to go beyond examining associations between exposures and outcomes to make the stronger inferences about causal relationships that are required to meaningfully inform policy. For instance, techniques such as causal mediation continue to be advanced20; while techniques such as marginal structural models make it feasible to simulate what intervention can realistically achieve.21 Techniques such as effect-measure modification can help to assess whether an intervention may have varying effects for different subgroups of children .22Utilizing secondary data in innovative ways requires careful thought and planning to address analytic challenges like attrition of those most disadvantaged from the cohorts over time.7 This includes accounting for the many interrelated factors influencing child health and development and their temporal ordering; considering the importance of timing of different exposures in determining the significance of their impact.23 Failure to do so presents a risk of treating single risk factors as if they occur in a vacuum, with the implication being narrow or isolated “magic bullet” intervention strategies with limited long-term impact.24When designing analyses, researchers require a nuanced complex systems perspective.25 RCTs have the further potential for innovative policy relevant designs, such as stepped wedge.26 In addition to making best use of existing data, we should also make best use of existing evidence, utilizing systematic reviews addressing social determinant risk factors from longitudinal population studies and policy relevant interventions.28In addition to such investigations in cohort data, larger data sources enable precision for subpopulations. For example, routine antenatal care data have informed how the Australian health care system can be improved for women of refugee backgrounds, which would be challenging to capture within mainstream cohorts.18 How to weigh up the goal of addressing inequities with the need to maximize overall public benefit is also complex; for example, when it is less cost effective to improve the outcomes of those who are the very worst off, than to improve outcomes of those slightly better off.29 Managing these concerns will be vital for researchers and policymakers seeking to build the evidence base.Ethical concerns have been raised regarding precision medicine that aim to identify individuals or populations “at risk”; such as privacy, and discrimination and stigmatization.6 Even the best evidence guided interventions may not work as intended,30 highlighting the need for continued evaluation and monitoring of policy efforts. As this new thinking enabled by recent methodological advances is implemented from concept to policy change, it will be vital to document case studies and exemplars to learn from and show what is possible, and evaluate this process itself.The ultimate translation of this work into precision policy is not without its complexities. Even when evidence carries clear and precise policy implications, hurdles remain in the way of policy action, including competing political interests, resource and time constraints, and siloing of government portfolios.Research designed to address or prevent child health inequity needs to enter a new phase of precision. The challenge is to develop ethical frameworks to define and prioritize inequities, and to build an evidence base with sufficient specificity to generate actionable policy implications capable of leading to measurable change. Greater precision in policy will help to direct limited public funds toward intervention opportunities that will have the greatest impact. This ensures that resources are put to the best possible use and maximizes return on investment. Redressing child inequities is both a social justice and economic imperative.


Kansas is updating the PASRR (Preadmission Screen and Resident Review) Level 1 screen per new guidance from the PASRR Technical Assistance Committee (PTAC), via a partnership between the State and university researchers. PTAC has directed states to screen for undiagnosed serious and persistent mental illness (SPMI) and also recommends screening for substance related disorders. Stakeholders were engaged through advisory workgroups and a content validity expert panel. These activities led to the creation of a revised PASRR Level-1 screen, but stakeholders also raised several concerns. PASRR law does not require Level-1 assessors to have professional training in mental health diagnoses or treatment, yet new guidelines asks them to screen for undiagnosed SPMI. Further, there are apparent discrepancies between these new guidelines and PASRR Level-2 criteria. Finally, current information management systems are not equipped to handle the higher security protocols associated substance use disorders. The draft instrument was tested with a sample of 103 nursing facility applicants by trained PASRR assessors and inter-rater reliability (IRR) was tested via a standardized vignette with 14 trained PASRR assessors. Only 3% of actual NF applicants were identified as possibly having an undiagnosed SPMI and only 43% of assessors correctly identified symptoms of a suspected SPMI in the standardized vignette, indicating poor validity and reliability in assessing for undiagnosed SPMI during the Level-1 screen. New PASRR guidelines may better ensure that nursing facility residents receive appropriate care for SPMI, however, there are many challenges to ensuring an accurate screen and supporting successful implementation.


The recent surge in cancer drug approval has provided us in cardio-oncology with a new and unique era, which modern medicine has not experienced before: the diminishing availability of “conventional” evidence-based medicine. The drastic and quick changes in oncology has made it difficult, and at times even impossible, to establish a meaningful evidence-based cardio-oncology practice by simply following the oncologists' practice. For the modern cardio-oncologist, it seems that a more proactive approach and methodology is needed. We believe that only through such an approach  the cardio-oncologist will obtain meaningful evidence to perform their every-day practice in this new era. Over the last few years, the field of cardio-oncology has seen a number of new developments, challenges, and changes in paradigms. First, with advancements in cancer therapy, long-term survival has reached an all-time high. In 2016, in the U.S. alone, the cancer survivor population increased to over 15 million with a projection to over 26 million by 2040. Of further interest, nearly three quarters of these patients are 65 years and older with a higher burden of comorbidities, most frequently cardiovascular in nature –7. Thus,+ may accelerate reactive oxygen species (ROS) formation (Fenton reaction)  . Anothereaction) .In distinction to the above, initial experience with trastuzumab outlined the occurrence of a different type of cardiac dysfunction (type 2) that was dose-independent and mostly reversible –17. TrasRecently, arguments against the type 1 vs. type 2 concept have arisen, in view of the fact that doxorubicin-induced cardiotoxicity is not always irreversible , 10, andFor the reasons outlined, any subtyping of cardiotoxicity is inherently difficult. While one may argue about some overlap between the type 1 and type 2 cardio-toxicities , the conA number of other intertwined molecular processes induced by various cancer treatments, including mitochondrial-related defects [e.g., iron accumulation , 29, imphttps://ascopost.com/news/september-2019/cancer-drugs-account-for-over-a-quarter-of-all-new-drug-approvals-in-the-us/). In view of this surge of new therapies, the recent practice of oncology has been changing very frequently and dramatically. One of the most impressive revolutionary milestones in this regard is the development of immune checkpoint inhibitors (ICIs). Currently, hundreds of phase I, II, and phase III/IV clinical trials of anti-PD-1, PD-L1, and CTLA-4 are being carried out across the globe . Other societies and regulatory institutions should follow with the goal of providing nationally and even universally accepted credentials . Aligned with these efforts is the need for standardization of the definition of cardiovascular toxicities in a joint, cross-disciplinary manner. Such initiatives will help clinical practice as well as research, allowing for the direct comparison of outcomes. Furthermore, there should be standardization not only in terms of outcomes but also in terms of availability of cardio-oncology services. Quality and outcomes are another aspect that will be key to further substantiate the importance of the field.Providing the evidence base for these practice and education related efforts is of utmost importance. It calls for research that will provide new insight, mechanistically, translationally, and clinically, and help transition cardio-oncology from a “Band-Aid” to an evidence-based practice approach. These research efforts should cover the entire continuum of cancer care, from before, to the during, and the after cancer therapy with most optimal prevention, surveillance, and treatment. Furthermore, at the time of drug development itself, its potential for cardiovascular toxicity should be carefully evaluated such that at the time of its introduction one can be prepared to expect and address emerging issues. Big data and artificial intelligence may aid in this regard and steer into a bright future. As outlined herein, what is needed are more proactive approaches to change the cardio-oncology practice from “dealing with the common final CV adverse effects” by merely following the oncology practice, to an evidence-based practice by learning the pathophysiology and principles of cardiovascular toxicities across cancer treatments .Changing paradigms, changing times, and changing minds, this is how we see the past, present, and future of cardio-oncology.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


This study aimed to investigate the methodological quality of clinical guidelines (CGs) for integrated Chinese and Western medicine (ICWM) to inform clinical practice and guideline development.  We searched PubMed, EMBASE, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang Data, VIP, five guideline databases, and four online book malls to identify ICWM CGs published up to January 11, 2019. Four independent appraisers assessed the quality of CGs using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument and evaluated six specific concerns for ICWM. The standardized scores were calculated for the individual AGREE II domains.  Sixty-two ICWM CGs were included. The median standardized scores in the six domains of AGREE II were 65% in scope and purpose, 46% in clarity of presentation, 26% in applicability, 24% in stakeholder involvement, 15% in rigor of development, and 0% in editorial independence. The quality of ICWM CGs was significantly associated with the publication year  and the development method . Only one ICWM CG obtained a direct recommendation for use, and 14 could be recommended for use after modifications. The intra-appraiser consistency of the AGREE II appraisal was good . ICWM CGs also lacked a systematic search of ancient traditional Chinese medicine (TCM) classics (40.3%), conversion of TCM recommendations from ancient Chinese to the vernacular (14.5%), a discussion of interactions between TCM and Western medicine (27.4%), and rankings of different ICWM choices (0%). Study Registration. This study has been registered at PROSPERO (no. CRD42018095767). Although an improvement after 2014 occurred, the current 64 ICWM CGs are generally of poor methodological quality. Only 15 ICWM CGs can be recommended for use directly or with modifications. As the key distinctions from Western/Chinese medicine CGs, the ICWM-specific recommendations are also insufficient for the ICWM CGs, especially for interactions between TCM and Western medicine and rankings of different ICWM choices.  Although Western medicine has become the mainstay of the health care system in China, traditional Chinese medicine (TCM), an ancient medical approach with 3000 years of history, is still widely practiced , 2. InteICWM practice, however, is difficult. TCM is fundamentally different from Western medicine in both theory and practice. Western medicine is based on modern scientific methods and evidence, whereas TCM uses philosophical perspectives to explain physiological and pathological changes in the human body, as manifested in its unique diagnostic method of syndrome differentiation and use of Chinese herbs and acupuncture to treat diseases . Due to An essential approach to improving ICWM practice is to develop and utilize clinical guidelines (CGs), which are recommendation documents systematically developed to standardize clinical decisions in specific clinical settings . To dateMany efforts have been made by methodologists to improve the quality of CGs. The Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument, developed in 2009, is a representative achievement of these efforts to assess the quality of CGs . Owing tA previous study explored the quality of ICWM CGs published before 2014 [This is a survey of currently available ICWM CGs published before January 11, 2019, using the AGREE II instrument. The study protocol is registered at PROSPERO (no. CRD42018095767). We report this study following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria where applicable .http://www.amazon.com, http://www.jd.com, http://www.amazon.cn, and http://www.dangdang.com). The keywords used for the search included “integrated Chinese and Western,” “guideline,” “consensus,” and “recommendation,” among others , and four online book malls  CGs developed for TCM or Western medicine alone; (2) no full text available; (3) translations; (4) CGs developed by a single author; (5) guideline-like textbooks; and (6) systematic reviews, narrative reviews, clinical pathways, and clinician training manuals.Two appraisers, independently and in duplicate, screened the bibliographies to identify potentially eligible CGs and then read the full text to determine the final eligibility. Discrepancies were resolved by discussion.The following information was extracted from the CGs included using a standardized, pilot-tested form: authors, publication year, publication form, type of CG (evidence-based or consensus-based), type of developer, scope, condition, numbers of pages and references, consensus method, evidence grading system, composition of development team, and funding sources.We used the AGREE II instrument to assess the quality of ICWM CGs across the following six domains: scope and purpose (3 items), stakeholder involvement (3 items), rigor of development (8 items), clarity of presentation (3 items), applicability (4 items), and editorial independence (2 items). The items in AGREE II are scored from strongly disagree (1 point) to strongly agree (7 points). A standardized score for each domain was calculated using the following formula: /(maximum score − minimum score)) × 100%. Finally, we performed an overall assessment of “whether you recommend this guideline for use” with the following standards proposed by previous studies , 18: (1)https://www.agreetrust.org/resource-centre/agree-ii/agree-ii-training-tools/). Before the formal appraisal, the appraisers performed a pilot exercise for two ICWM guidelines with different methodological qualities and discussed and addressed discrepancies. The formal appraisal was performed using an official online platform “My AGREE PLUS (https://http://www.agreetrust.org/my-agree/),” which is widely used in AGREE II appraisals and may enhance consistency between appraisers [Four appraisers who had experience in the development and appraisal of CGs independently assessed the quality of each CG. To enhance the consistency between the appraisers, they were trained in both English and Chinese versions of the AGREE II user's manual , 20, a ppraisers , 23.To assess whether the CGs appropriately specified key concerns for ICWM, we consulted five clinicians each in Western medicine and Chinese medicine to collect the information they were most interested in and the gaps they most frequently faced when using ICWM guidelines. We determined the following six ICWM-specific concerns by a consensus meeting: (1) whether the CG included evidence from ancient TCM classics; (2) whether ancient Chinese in the TCM recommendations had been converted to the vernacular for the comprehension of non-TCM practitioners; (3) whether the CG provided the principles of the addition and subtraction of TCM interventions based on syndrome differentiation; (4) whether the CG specified the interactions between TCM and Western medicine; (5) whether the CG ranked the efficacy and safety of different ICWM interventions; and (6) whether the CG provided monitoring criteria for both diseases (Western medicine concept) and syndromes (TCM concept). All these items received an answer of “yes” or “no.” The assessment was also performed by four appraisers, and they achieved consistency through discussion.U test or the Kruskal–Wallis H test, and the difference was significant if the p value was less than 0.05. The intraclass correlation coefficient (ICC) and 95% confidence interval (CI) were calculated to assess consistency among the appraisers using a two-way mixed model; an ICC <0.50, 0.50–0.74, 0.75–0.89, and 0.90–1.00 indicated poor, fair, good, and excellent consistency, respectively [We calculated the mean, standard deviation, median, interquartile range (IQR), range, or proportion to describe the characteristics of the CGs, standardized AGREE II scores, and additional items. We performed stratified comparisons of CGs with different characteristics using the Mann–Whitney ectively .As shown in The standardized AGREE II scores of the included CGs are shown in This domain requires the CGs to explicitly describe the objectives and target population. The median score was 65.3% (IQR: 55.6–70.8), with 54 CGs (87.1%) scoring >50% but only two (3.2%) scoring >80%.This domain requires the CGs to assemble a multidisciplinary guideline development team, consider the values and preferences of patients, and define target users. The median score was 23.6% (IQR: 18.1–33.3). Only two CGs (3.2%) scored >50%. Twenty-nine CGs (46.8%) provided author affiliations or specialties, but only 11 (17.7%) involved methodologists. No guidelines considered the values and preferences of patients.With regard to this domain, CGs should clearly describe the search strategy and rigorously assess the evidence. The median score was 14.6% (IQR: 9.4–21.4). Only three CGs scored >50%. Of the six CGs (9.7%) that reported the evidence grading system, two (3.2%) used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and the others used less rigorous tools. To build consensus, 11 CGs (17.7%) used the Delphi method, and 5 (8.1%) used the meeting method.This domain requires the CGs to clearly present recommendations and provide multiple options for health issues. The median score was 45.8% (IQR: 37.5–55.6), and 23 CGs (37.1%) scored >50%. Thirteen CGs (21.0%) used tables or graphs to present the key recommendations.For this domain, the CGs must consider facilitators or barriers of application and provide monitoring criteria. The median score was 25.0% (IQR: 13.9–43.1), and 11 CGs (17.7%) scored >50%. Only one CG provided a diagnostic manual as an additional tool to facilitate application.This domain requires the CGs to be free from competing interests. We were unable to calculate the median and IQR for this domain because most guidelines failed to report the relevant information. Six CGs (9.7%) reported nonprofit government funding or declared no competing interests and scored from 83.3% to 100%.Only one CG obtained a direct recommendation for use based on the criterion of a score greater than 60% in all six domains , 33, 73.Overall, the intra-appraiser consistency was good in all AGREE II domains, as indicated by ICC values ranging from 0.813 to 0.998 .Based on the assessment of ICWM-specific concerns, 25 (40.3%) guidelines cited ancient TCM classics, but only 9 (14.5%) adequately converted ancient Chinese to plain text in the TCM recommendations. Of the 60 treatment CGs, 31 (50.0%) provided the principles on addition and subtraction of TCM interventions, 17 (27.4%) described interactions between TCM and Western medicine, and 14 (22.6%) provided monitoring criteria for both diseases and TCM syndromes. No guideline included recommendations on ranking the efficacy and safety of different integrated treatment choices. The detailed results are presented in This study is a significant update of a previous study on the quality of ICWM CGs. We used a precise definition of ICWM CGs and performed a comprehensive search; as a result, we added 32 new and 9 updated ICWM CGs to those detailed in the previous survey. With good intra-appraiser consistency, our results revealed that the overall methodological quality of ICWM CGs is poor. Only one ICWM CG was directly recommended for use, and fourteen CGs can be recommended after modifications. Compared with 626 Western medicine CGs , the ICWThe rigor of development is a vital component ensuring the quality of CGs, but the score for this domain was very low across the ICWM CGs. Using an evidence-based framework to develop CGs allows for the systematic identification of the current evidence, a rigorous and transparent assessment, and the development of evidence-informed recommendations, enhancing the quality of CGs . The strUsing the publication year of a previous study assessing the quality of ICWM CGs as a time node, we found that CG quality in five domains was better for those published after 2014 than those published during 2014 or before. This subgroup difference should also be associated with the better quality of evidence-based CGs; in fact, most (93.3%) evidence-based CGs included in the study were published after 2014. We consider that there were two possible reasons for the increasing tendency of publishing evidence-based CGs. First, the amount of high-grade evidence for ICWM such as systematic reviews increased rapidly after 2014, which is the foundation for developing an evidence-based CG. Second, the methodology of evidence-based CG development  became more complete and popular in China after 2014.Both evidence- and consensus-based CGs require consensus methods to formulate recommendations. The formal consensus methods include the Delphi method, the nominal group method, and consensus-building meetings . Some ICThere were particularly conspicuously low scores in the editorial independence domain. In general, the development of a CG requires considerable physical resources and financial support, which may be associated with potential bias . Nevertheless, because there are generally no requirements for a conflicts of interest statement for publication , most ICThis survey also investigated six ICWM-specific concerns that represent key differences between ICWM guidelines and guidelines for Western or Chinese medicine alone and are associated with a better methodological quality of ICWM CGs. As a traditional medical science, TCM practice is highly dependent on evidence from ancient classics . DespiteA growing controversy in TCM is the potential toxicity of Chinese herbs . Hence, There are some limitations of this study. Although we searched electronic databases and online book malls, some ICWM CGs that have not been published but are being used in clinical practice may have been omitted. We empirically consider these CGs to be of low quality. Moreover, because AGREE II does not provide detailed criteria, we used a nonofficial standard that has been applied in several previous studies for the overall assessment , but the judgment boundary in the standard is not fully recognized.Although the quality of ICWM CGs has been improving, there are still substantial methodological gaps. We have several suggestions for future ICWM CGs based on the results of this study. First, assembling an interdisciplinary team, including Western medicine experts, TCM experts, economists, patient representatives, and methodologists familiar with guideline development methodology and AGREE II, would help to reduce methodological limitations. Additionally, a methodology training program for all team members before development may be helpful. Second, we strongly recommend using the GRADE approach to assess the quality of evidence and formulate recommendations. A specialized evidence grading system is warranted for assessing ancient TCM classics. Third, all ICWM CGs need to expand upon recommendations regarding ICWM-specific concerns, especially regarding interactions between Western medicine and TCM and a ranking of recommendations based on comprehensive considerations of efficacy and safety. Finally, obligatory requirements for disclosing the role of funders and conflicts of interest are indispensable for improving the editorial independence of ICWM CGs.The current 62 ICWM CGs are generally of poor methodological quality, especially in terms of stakeholder involvement, rigor of development, applicability, and editorial independence. The quality of CGs published after 2014 and evidence-based CGs are relatively high. Only one and fourteen ICWM CGs could be recommended for use directly and with modifications, respectively. Most ICWM CGs fail to provide important ICWM-specific concerns, including ancient TCM classic evidence, translation of ancient Chinese, interactions between TCM and Western medicine, and rankings of different ICWM choices. Rigorous methodology and ICWM-specific considerations are thus warranted in future ICWM CGs to improve their quality and applicability.


Bile acids (BAs) are amphipathic sterols primarily synthesized from cholesterol in the liver and released in the intestinal lumen upon food intake. BAs play important roles in micellination of dietary lipids, stimulating bile flow, promoting biliary phospholipid secretion, and regulating cholesterol synthesis and elimination. Emerging evidence, however, suggests that, aside from their conventional biological function, BAs are also important signaling molecules and therapeutic tools. In the last decade, the therapeutic applications of BAs in the treatment of ocular diseases have gained great interest. Despite the identification of BA synthesis, metabolism, and recycling in ocular tissues, much remains unknown with regards to their biological significance in the eye. Additionally, as gut microbiota directly affects the quality of circulating BAs, their analysis could derive important information on changes occurring in this microenvironment. This review aims at providing an overview of BA metabolism and biological function with a focus on their potential therapeutic and diagnostic use for retinal diseases. Selenarctos thibetamus) and brown (Ursus arctos) bears have been used for thousands of years to remove toxins from the body, stop convulsions, and improve vision [Bile acids (BAs) are hormones which serve many different roles in the body’s digestive and metabolic systems. Their unique chemical composition contributes to their reported anti-inflammatory and antioxidant effects, explaining their historical use in traditional Chinese medicine (TCM) ,2,3. A te vision ,3. In TCe vision ,3. Modere vision ,5,6. Thee vision .Current interest in BAs arose from the discovery of their signaling properties and ability to regulate the activity of many genes through the orphan nuclear receptor farnesoid X receptor (FXR) . FXR agoBAs eliminate cholesterol, aid in lipid transport, and stimulate bile flow and biliary phospholipid secretion . BAs maiBAs are produced in hepatocytes and are transported to the gallbladder through bile canaliculi. There are two major pathways for BA synthesis: the classical and alternative pathways ,20 Figu. The claThe alternate pathway is initiated by sterol 27-hydroxylase (CYP27A1), a mitochondrial cytochrome P450 enzyme that is widely distributed in macrophages and most tissues ,23,24. SOnce in the intestinal lumen, gut microbiota produces secondary bile salts by modifying primary BAs with 7α-hydroxylation, deconjugation, oxidation, and epimerization of hydroxyl groups on carbon-3, carbon-7, and carbon-12 ,25,26. BUnconjugated BAs are reabsorbed into intestinal enterocytes via passive diffusion in the jejunum and colon, whereas conjugated BAs, bile salts, are reabsorbed through a sodium-dependent BA transporter (ASBT) in the jejunum ,31. WhilThough BAs are an integral part of numerous biological processes, they can also exert toxic effects and cause inflammation, apoptosis, and cell death ,34,35. BStudies have shown that the accumulation of hydrophobic BAs inside hepatocytes leads to their injury and death. In one study, hepatocytes expressed dramatic levels of subcellular damage when exposed to concentrated CA and CDCA . The canAside from their hydrophobicity, abnormal amounts of BAs can lead to toxic effects on hepatic cells as well. Decreased BA concentration will stimulate hepatic cell apoptosis, while increased BA concentration will stimulate necrosis ,41. CytoUDCA and TUDCA, although present at very low circulating levels in humans, have been studied for their cytoprotective effects due to their hydrophilic nature and low toxicity . Their mBA pharmacological use has been applied to pathologies such as cholelithiasis, primary biliary cirrhosis, primary sclerosing cholangitis, and cystic fibrosis and is being suggested for neurodegenerative disorders associated with increased apoptosis such as Huntington’s Disease ,44. The Some studies demonstrate that the mechanism by which UDCA protects membranes is dependent on membrane cholesterol. In one study, cholesterol was found to influence the toxicity of both UDCA and the highly toxic sodium deoxycholate (SDC). UDCA was able to mitigate the cytotoxic effects of SDC only in the presence of cholesterol, whereas, enhancing its cytotoxic effects in the absence of cholesterol. This relationship of events suggests that the extent of UDCA cytoprotective effects is dependent on the level of cholesterol in membranes. In the context of treating cholestasis patients with UDCA, one must consider changes in membrane cholesterol composition that might affect the efficacy of this drug .cerebrotendinous xanthomatosis, a rare congenital disease characterized by several neurological and ocular symptoms such as cataracts, neurological dysfunction, and premature retinal degeneration [-/- mice [Although the liver is the primary site of BA production, several recent studies have identified extrahepatic production sites, including the brain and retina ,21. The neration . One stu-/- mice . Combine-/- mice . CYP46A1-/- mice . A singl-/- mice . Based o+/taurocholate co-transporting polypeptide  and the apical sodium-dependent BA transporter , which serve their primary transport functions in the liver and intestine, respectively. The gene SLC10A4 has been localized in the human eye, and it is associated with cholinergic synapses throughout the central nervous system. While SLC10A4 is also responsible for encoding protein P4, little data supporting the functional properties of the P4 gene is currently available [BAs require essential transporters to maintain their enterohepatic circulation and facilitate their active transport through membrane barriers in the liver and intestine. The sodium BA cotransporter family (SLC10) is a solute carrier family of genes that has been found to contain several BA transporters localized in many different tissues in the body. Most studied are the Navailable ,51.Emerging evidence suggests that aside from their conventional biological function in the enterohepatic system, BAs are also important signaling molecules  by activIn the last decade, studies on the usefulness of BAs in the treatment of ocular diseases have gained great interest in the scientific community. Particularly, UDCA and TUDCA are reported to be beneficial against photoreceptor degeneration, ganglion cell death, cataract, diabetic retinopathy (DR), etc. . PreviouAlthough the mechanism of action of UDCA and TUDCA remains unclear, it is thought to involve suppression of both caspase-dependent and caspase-independent apoptosis, likely by inhibiting the release of the apoptosis-inducing factor (AIF) from the retinal pigment epithelium (RPE), photoreceptors, and retinal ganglion cells (RGC) ,61,62.Retinal detachment, oxidative stress, and inflammation are also a key contributor to photoreceptor degeneration following their detachment from the RPE . PhotoreIn galactosemic rats, TUDCA treatment alleviated cataract formation by inhibiting the unfolded protein response (UPR)-dependent pathway . CataracOne study has explored the significance of TUDCA structural resemblance to compounds that bind to a light-activated form of rhodopsin to inhibit the activation of transducin. This study used computer modeling systems to show that TUDCA docks to light-activated rhodopsin using a similar mode of binding to the C-terminal domain of the transducin alpha subunit. These results suggest that TUDCA specific interaction with rhodopsin may contribute to its effect as a potential therapeutic compound for degenerative retinal diseases .Retinal degenerative diseases are important causes of blindness with little or no present effective cures. BA therapeutic potential has been tested in several models of retinal degeneration. Leber congenital amaurosis (LCA) is a form of retinal dystrophy that often leads to severe vision impairment and blindness; it has been shown that ER stress induced by S-opsin aggregation leads to rapid cone degeneration ,73,74. TIn one model of light-induced retinal damage, TUDCA treatment was shown to reduce superoxide radical levels . TUDCA tIn models of retinitis pigmentosa (RP), TUDCA has also been studied as a potential therapeutic agent. The common outcome of the RP disease family includes apoptosis of rods followed by degeneration of cones ,78,79. Ord10 mice to test the efficacy of TUDCA in RP [Boatright et al. utilized CA in RP . Rd10 miCA in RP . In anotCA in RP . At P30 CA in RP  resembliCA in RP . TUDCA tCA in RP  and signCA in RP .In another study of retinal degeneration, photoreceptor degeneration in mice retinas was chemically (N-methyl-N-nitrosourea) induced . To explBAs were also tested in models of optic nerve injury. Optic nerve transection was performed on C57BL/6 mice following systemic TUDCA treatment for 10 days. Immunohistochemistry staining on retinal flat mounts indicated a loss of 60% of RGC in control mice, which was completely prevented in mice treated with TUDCA .Diabetic retinopathy, a retinal neurovascular disorder, is the leading cause of blindness in adults of working age groups in the Western world ,87. UDCAPericytes play an important role in maintaining vascular integrity, and it is thought that retinal pericytes loss, an early hallmark of DR, leads to the BRB breakdown ,90,91,92TGR5 receptor plays an important role in regulating metabolic homeostasis . TGR5 acAge-related macular degeneration is known to result in severe visual loss due to the development of choroidal neovascularization (CNV) along with related manifestations, such as subretinal hemorrhage, RPE detachment, and fibrovascular disciform scarring, also known as wet or exudative AMD ,99,100. Further evidence of UDCA therapeutic potential was seen in our recent study of ROP, a leading cause of preventable blindness in children ,104. We Together, these findings support the idea that BAs have the potential to show their effects at nearly every structural layer of the eye. Evidence continues to support their therapeutic potential in neurodegenerative and ocular disorders.The human gut is a densely populated ecosystem containing numerous bacteria that coordinate with the host and facilitate the digestion of exogenous foods and the generation of secondary metabolites. While the bacteria found here are primarily obligate anaerobes, facultative anaerobes, archaea, and yeast also reside in the gut . BacteriClostridium, Bifidobacterium, Lactobacillus, Bacteroides, and Enterococcus genera, have the ability to deconjugate BAs into primary BAs with BSH, which hydrolyze the BA amide bond [Bacteroides, Clostridium, Lactobacillus, and Bifidobacterium contain genes which encode BSH. It is suggested that BSH activity is used by bacteria as a BA detoxification mechanism, which can alter both the local gastrointestinal and the systemic functions of the host organism [Bacteroides, Eubacterium, Clostridium, Bifidobacterium, Lactobacillus, Peptostreptococcus, and Escherichia as well as bacteria of the genera Clostridium, Peptococcus, and Fusobacterium, respectively [Eubacterium and Clostridium genera can transform primary BAs into secondary BAs with 7-α-dehydroxylation [Once in the large intestine, many intestinal bacteria, specifically those of ide bond . Specifiorganism . Aside fectively . Subsequxylation .BAs are known to affect many systems in the body, and most studies demonstrate many of these effects can be toxic . The ampDisruption of the gut microbiome alters BA metabolism and leads to deficits in the metabolic pathways they regulate, including glucose and cholesterol homeostasis; by doing so, they threaten the host’s overall health . Gut micBAs possess unique properties that make them candidates for the treatment of various diseases characterized by inflammation and oxidative stress. Secondary BAs like UDCA and TUDCA are more hydrophilic and less cytotoxic than their primary BA counterparts, making them a candidate for therapeutic treatment. While UDCA and TUDCA are found at low levels in systemic in humans, they have been applied to pathologies like cholestasis, cystic fibrosis, and primary biliary cirrhosis for their pharmacological qualities. The gut microbiota converts primary BAs to secondary BAs, and current evidence indicates the gut microbiome plays a significant role in BA circulation. Although the retinal BA pathway and BA interactions in the eye are not fully understood, it is known that the gut microbiome and its resulting effects on retinal BAs may play a central role in ocular disease. Future investigation is needed to determine the mechanism by which changes in the gut microbiome affect retinal diseases and how BA therapy can modify this interaction.


The PFAS measured showed excellent agreement with certified plasma PFAS concentrations in NIST SRM 1957 reference serum. The method was tested on serum samples from 20 healthy individuals. In this proof-of-concept study, we identified significant associations between plasma PFAS and BA levels, which suggests that PFAS may alter the synthesis and/or uptake of BAs.There is evidence of a positive association between per- and polyfluoroalkyl substances (PFASs) and cholesterol levels in human plasma, which may be due to common reabsorption of PFASs and bile acids (BAs) in the gut. Here we report development and validation of a method that allows simultaneous, quantitative determination of PFASs and BAs in plasma, using 150 μL or 20 μL of sample. The method involves protein precipitation using 96-well plates. The instrumental analysis was performed with ultra-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS), using reverse-phase chromatography, with the ion source operated in negative electrospray mode. The mass spectrometry analysis was carried out using multiple reaction monitoring mode. The method proved to be sensitive, robust, and with sufficient linear range to allow reliable determination of both PFASs and BAs. The method detection limits were between 0.01 and 0.06 ng mLThe online version of this article (10.1007/s00216-019-02263-6) contains supplementary material, which is available to authorized users. In clinical studies, both in metabolomics and in environmental exposure studies, the volume of sample available for analysis is often restricted. Thus, it is desirable that the analytical methods can assay multiple substance classes simultaneously, while using as small volume of sample as possible. This presents a challenge, both regarding the chemical characteristics of the compounds that can be quantitatively covered by a single extraction and/or analytical method, as well as in terms of the concentration range of said substances which can be assayed for. While several methods have been developed for untargeted analyses which can simultaneously assay a large number of metabolites, it remains problematic to analyze simultaneously both specific metabolites and exogenous compounds , with the main challenge typically being the low concentrations of the latter.In this study, we demonstrate the development of a targeted method for the analysis of two distinct compound classes, namely (i) endogenous bile acids (BAs) and (ii) exogenous per- and polyfluoroalkyl substances (PFASs) in human serum or plasma. BAs are metabolites that facilitate the digestion and absorption of lipids in the small intestine and they are also important metabolic regulators involved in the maintenance of lipid and glucose homeostasis , 2. PFAShttps://www.efsa.europa.eu/sites/default/files/news/efsa-contam-3503.pdf). Interestingly, it has been hypothesized that 7-alpha-hydroxylase (CYP7A1), which catalyzes the first and rate-limiting step in the formation of BAs from cholesterol, may be downregulated by PFASs − and [FSO3]− were used for quantification of PFCAs and PFSAs, respectively. Additional 1–2 product ions were monitored as qualification ions except for PFPeA and PFHxA, for which only one product ion was monitored. For BAs, monitoring of the transitions between molecular anion [M–H]− and one to two product ions including [SO3]−, [taurine–H]−, [CH2CHSO3]−, and [NH2CH2COO]− for the conjugated BAs and [M–H]− and [M–H–2H2O]− for the non-conjugated BAs.MS analysis was performed in multiple reaction monitoring (MRM) mode and experimental details of the MS/MS method are given in ESM Table For method validation, the following parameters were investigated: linearity, method detection limit (MDL), repeatability, accuracy and precision, recovery, and matrix effect. Linearity was determined with matrix-matched standards, and plotted as relative peak areas  versus analyte concentration.The analytical method was a combination of two methods that we developed earlier for BAs and PFASs , 16. Them/z = 499 and major fragment at m/z = 80 and tend to co-elute), we specifically monitored two different (other than 499 > 80) product ions unique to the two compounds in order to ensure interference-free quantitation   of the matrix-matched calibration curves ranged from 0.9995 to 0.99998 for PFASs and from 0.9906 to 0.9997 for BAs. The relative response factors (RRFs) of the calibration curve ranged between 0.603 and 1.47 for PFASs and between 0.23 and 1.70 for BAs with relative standard deviation < 15% for all major serum PFASs and < 22% for the broad range of BAs with the exception of three BAs above 25%: CA (26%), HCA (27%), and ωαMCA (31%).The linearity (n = 7). Overall, the method performed well, giving MDLs in the range of 0.01–0.06 ng mL−1 for PFAS using 150 μL of sample. The MDLs for BAs were in the range of 0.002–0.152 ng mL−1, with the exception of CA (0.1 ng mL−1) and GCDCA (0.56 ng mL−1), which gave higher MDLs due to higher background noise in the water blanks. With a 20-μL sample volume, the MLDs were in the range of 0.02–0.5 ng mL−1 for all PFASs except for PFUnDA, for which the MDL was 10 ng mL−1. For BAs, the MLDs were in the range of 0.0025 to 1.0 ng mL−1 with the exception of wMCA and 12-oxo-LCA which had higher MDL (10 ng mL−1).MDLs were determined by calculating the mean concentrations plus three times the standard deviation in water blanks run with the sample batch , ranged from 2 to 7% for all major plasma PFAS, with the exception of PFUnDA at 24% in the NIST sample  increased re-uptake of the bile acids in the gut, (ii) decreased clearance from the blood, (iii) increased production of the conjugated bile acids in the liver, or (iv) decreased de-conjugation of them by the microbiota, or any combination of these. Additionally, our results appear to suggest increased microbial formation of LCA. Indeed, PFAS exposure has been shown to cause alteration in gut microbiota, with higher exposure to PFAS associated with reduced microbiome diversity . On the Taken together, our observed associations between PFASs and BAs are potentially important for our understanding of cardiometabolic diseases, which is because BA metabolism is known to play a role in the pathogenesis of type 2 diabetes (T2D), atherosclerosis, and non-alcoholic fatty liver disease (NAFLD) . TaurineThe method presented here is suitable for fast, automated analysis of PFASs and BAs from human serum, and the sample amount can be reduced to 20 μL, however, with some loss of sensitivity. Our validation of the method demonstrated that the method is robust and accurate. Our preliminary findings that various PFASs have significant association with BAs support the notion that they may play a role in the health impacts of PFAS exposure, such as the known impact of PFAS on cholesterol levels, and in metabolic pathologies such as T2D and NAFLD. Taken together, our findings warrant further investigation of the impact of both specific and mixtures of PFAS on BA metabolism, including the potential role of gut microbiota. Such studies may provide valuable insight into the pathogenesis and varying incidence of common metabolic and immune-mediated inflammatory disorders.ESM 1(PDF 419 kb).


Signals of adverse drug reactions (ADRs) form the basis of some regulatory risk-minimization actions in pharmacovigilance. Reviews of limited scope have highlighted that such signals are mostly supported by reports of ADRs or multiple types of evidence. The time that elapses between a report of a suspected ADR and the communication of a signal has not been systematically characterized. Neither has the features of reports of suspected ADRs that authors used to support putative causal relationships, although difficulties with establishing causal relationships between medicinal products and adverse events have been highlighted. The objectives of this study will be to describe the evidence underpinning signals in pharmacovigilance, the features of reports of ADRs supporting signals, and the time that it takes to communicate a signal.We shall retrieve records from PubMed, EMBASE, Web of Science, and PsycINFO (from inception onwards), without language/design restrictions, and apply backward citation screening. We shall hand-search the websites of 35 regulatory agencies/authorities, restricted publications from the Uppsala Monitoring Centre, and drug bulletins. Signals will be requested from the competent stakeholder, if absent from websites. We shall use VigiBase, the World Health Organization’s Global Individual Case Safety Report database, to determine the dates on which ADRs were reported. We shall manage records using EndNote (v. 8.2); one reviewer will screen titles/abstracts and full texts, a second will cross-validate the findings, and a third will arbitrate disagreements. Data will be charted via the Systematic Reviews Data Repository, following the same procedures as for data retrieval. Evidence will be categorized according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. Features of reports of ADRs will be coded. Tables will display frequencies of types of evidence and features of reports of ADRs. We shall use plots or pictograms (if appropriate) to represent the time from the first report of a suspected ADR to a signal.We expect the findings from this review will allow a better understanding of global patterns of similarities or differences in terms of supporting evidence and timing of communications and identify relevant research questions for future systematic reviews.osf.io/a4xns A systematic review of definitions, later adopted by the Council for International Organizations of Medical Sciences, defined a signal in pharmacovigilance as “information that arises from one or multiple sources (including observations and experiments), which suggests a new potentially causal association, or a new aspect of a known association, between an intervention and an event or set of related events, either adverse or beneficial, which would command regulatory, societal or clinical attention, and is judged to be of sufficient likelihood to justify verificatory and, when necessary, remedial actions” , 2.Based on this definition, a signal can be supported by diverse levels of evidence, ranging from one or more reports of suspected adverse drug reactions (ADRs) to observational studies and randomized clinical trials –5. On thComparative assessments of signals discussed at the Pharmacovigilance Risk Assessment Committee have suggested that reports of ADRs often supported signals, but that support from multiple sources of evidence increased the likelihood of regulatory action (e.g. changes to Summaries of Product Characteristics) , 9. SimiAn important component of detection of signals of ADRs is clinical judgment of the data. The Bradford-Hill viewpoints or guidelines  and otheOver several decades of pharmacovigilance, many definitions of signals have been developed and applied, and different types of studies have been used to detect signals, resulting in a complex body of evidence whose breadth has been only partly characterized. Delays to withdrawals have been investigated systematically, while those relating to the time to signal have been limited in scope. Furthermore, while reports of ADRs remain a staple in signal detection, it is unclear to what extent their features  have been described or contributed to putative causal relationships. This is relevant when one considers that recent data-driven methods to prioritize signals arising from reports of ADRs are based on the quality of information of the reports themselves and a limited set of features, i.e. the presence of a narrative, the geographical distribution of the reports of ADRs, how recently reports of ADRs have been entered into a database, and a numerical measure of data completeness , 29. ComWe therefore believe that it is worthwhile to conduct a scoping review, since such reviews are suitable for addressing broad exploratory questions pertaining to types of evidence in an area of research –32The aims of this scoping review are as follows: (a) to provide an evidence synthesis for decision-making at a regulatory level; (b) to collate signals currently in different platforms; (c) to produce an overview of the types and levels of evidence of studies that support signals; (d) to highlight any differences or similarities in assessment of the evidence used to support signals, with a particular focus on reports of ADRs; and (e) to better understand the delays before signals are detected and to clarify whether they have changed over time.The six-step framework introduced by Arksey and O’Malley  and refiosf.io/a4xns) and is being reported in accordance with the reporting guidance provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement  and iteratively refined the queries in line with the published literature on search strategies for adverse effects , 45. MorRelevant articles will be retrieved as follows:We shall search MEDLINE , EMBASE (1974–present), PsycINFO (1806–present), and Web of Science  for signals published by organizations involved in pharmacovigilance and/or independent research groups  and pharmaceutical companies. We shall use Web of Science to perform backward citation screening; if we cannot use Web of Science, we will use Google Scholar.We shall search the English language websites of 35 regulatory authorities or organizations involved in the World Health Organization (WHO) Programme for International Drug Monitoring, using the websites’ search engines, to identify communicated signals, expanding the list of countries compiled by Onakpoya et al.  where poWe shall hand-search the Uppsala Monitoring Centre (UMC)’s SIGNAL Document, the WHO Pharmaceuticals Newsletter, the Full List of WHO Medical Product Alerts, the WHO Drug Information, Australian Prescriber, Prescrire International, and other drug bulletins available in English via the International Society of Drug Bulletins’ index for relevant records.We shall query Google Scholar in incognito browser tabs. We shall evaluate the results as long as 20 results (two consecutive pages) yield at least one useful article.We shall also search OpenGrey and GreyNet International.We shall use VigiBase , to obtaThe planned data lock point for the retrieval of all records is the end of August 2020.A draft search strategy for PubMed and Google Scholar and sources of grey literature are provided as Additional file 2.Since one of our goals is to better understand the evidence underpinning signals, we want to be as comprehensive as possible, while being able to remove irrelevant publications. Thus, we will not constrain by study design, language, or specific population: primary or secondary research using qualitative or quantitative methods will be eligible. We shall consider as eligible a priori disproportionality analyses , 39, 40,2 ≥ 4 with or without a minimum of three reports of ADRs. To account for this, we shall not apply standard thresholds, but we will require the presence of a threshold for significance, whether referenced or in the full text.Clearly, these criteria are insufficient for discarding all irrelevant publications, and we may obtain a large list of references. We shall therefore stipulate that any retrieved study should concern patients . We have therefore devised criteria for exclusion. First, descriptive, experimental, and observational study designs that are not unequivocally conducted to detect signals, even though the original authors may have described their findings as “signals”. An explicit description of the findings as “signals” in the abstract and in the full text will be necessary for eligibility. Secondly, different thresholds for significance may be used in disproportionality analyses, e.g. PRR ≥ 2 with ΣThese criteria preserve the views of the original authors, minimize biases at our end, and allow us to work with a manageable data set.Disproportionality analyses , 39, 40 Systematic reviews with or without meta-analyses, randomized controlled trials, observational studies, or more recent methods for signal detection  as detailed in , in whicQualitative appraisals of individual reports or series of reports of ADRs, by either structured or unstructured methods , that hGovernment or agency reports, working papers, and drug bulletins, whose entries have been indexed as signals or which explicitly describe an association between one or more medicinal products/ADRs as “signal” (viz. European Medicines Agency ).Documents in languages other than English will be included if the review team can translate them into English. Requests for translations will be issued to the publishing stakeholder if the review team cannot translate.Abstracts or papers for which the full texts are unavailable.Documents that claim that the evidence does not support a signal or that no signal was detected.Signals that are communicated in the same or similar form or substance more than once by the same stakeholder .Non-English documents and websites for which a translation is unavailable.All retrieved records will be imported into EndNote™ X8.2. We shall deduplicate records manually, based on the lists of authors, titles, abstracts, journal, and pagination.Retrieved titles and abstracts will be reviewed by DS (first author) against the inclusion and exclusion criteria. IJO (last author) will cross-validate the findings. Disagreements will be resolved by arbitration by JKA (second author).Eligible records will be reviewed by full text by DS. IJO will cross-validate the findings. Disagreements will be resolved by arbitration by JKA. Data charting will follow the same process.We shall extract data to compute descriptive statistics in a form created in the Systematic Review Data Repository, adapted to scoping reviews . SpecifiTo extract the features of reports of ADRs that were considered as supporting putative causal relationships, we shall include a set of pre-determined codes in the extraction form as multiple-choice checkboxes, each followed by a free-text field. These are “Time-to-onset”, “Dose-response relationship”, “Positive de-challenge”, “Positive re-challenge”, “Site-specificity of ADR”, and “Population-specificity of ADR”. Quotations from the full texts will be inserted in the respective free-text field. DS has been involved in qualitative assessments of reports of ADRs, and the codes have been based on his experience.The extraction form will include a free-text field “Other” to accommodate the inclusion of other unanticipated features of reports of ADRs supporting putative causal relationships. Quotations from the full texts will be inserted in the field when they do not fall in any of the pre-specified codes and will be iteratively assigned codes in the form itself.We shall adopt a narrative approach to present the findings; these will be summarized by descriptive statistics and graphical illustrations after having standardized terminologies across included studies  and codes that relate to the unanticipated features of reports of ADRs.We shall code medicinal products to substance level, using the WHO Drug Dictionaries , and, where possible, code adverse events at the Low-Level Term level of the hierarchy in the Medical Dictionary for Regulatory Activities® (MedDRA) (latest version available at the start of the review), .We shall translate types of evidence to the Oxford Centre for Evidence-Based Medicine levels of evidence frameworkCodes extracted from the form in step 4 will be harmonized in the case of variance.We shall calculate absolute frequencies of types of evidence in Microsoft Excel and group them by type of stakeholder and/or year of publication. Similarly, we shall calculate the absolute frequencies of codes and publishing stakeholders.The complete (dd-mm-yy) date on which an ADR occurred, as stated in reports of ADRs entered in VigiBase, will be used to calculate the time-to-signal, by accounting for the date on which the signal relating to the same combination of medicinal product and the adverse effect was communicated. If the date of occurrence of the ADR is unavailable or incomplete, we shall use the first date on which the report was entered into VigiBase instead . This field is necessarily complete, and follow-up reports are reconciled to it in VigiBase. For signals communicated by multiple stakeholders, the earliest date of communication will be considered. Depending on available resources, we may calculate the time-to-signal, beginning from the date on which cumulative disproportionality reaches statistical significance for the information component (lower limit of the 95% CI > 0).We shall present frequencies of types of evidence grouped by stakeholders in tables. We shall use figures (e.g. histograms) to present changes in frequencies of types of evidence over intervals of time.We shall present all signals in tabular format, as combinations of medicinal product/ADR, or as medicinal product/medicinal product/ADR in the case of drug-drug interactions, together with their year of publication, stakeholder, eligibility criteria, population, setting, confounding factors, year of first entry in VigiBase, year of occurrence of the ADR (where available), and definition of signal. When signals are supported by spontaneous reports of ADRs, the codes of features of the reports of the ADRs will be included. Each signal will be accompanied by the time to signal.A separate table will include SDRs and will include the same fields as above, plus the metric for detection .We shall illustrate the time to signal for each stakeholder, in timeline plots and pictures (if appropriate).Illustrations will be created using Microsoft Excel.The results of the scoping review will consist of an overview of the levels of evidence underpinning signals. We shall highlight any discrepancies across stakeholders in levels of evidence, times to signal, and the most frequent features of reports of ADRs used to support putative causal relationships. We shall contextualize our findings with other published records and report the limitations of the study and recommendations for research. Variations from the published protocol will be presented and amendments made to the registered version. The full review will be submitted to a peer-reviewed journal for publication.To the best of the authors’ knowledge, this would be the first study to systematically chart the evidence in support of signals and draw international comparisons of its levels using a standardized framework. Previous characterizations of the evidence underpinning “initial safety signals”  have focWe expect to retrieve publications that report large lists of SDRs. This will pose some challenges, particularly during data charting, as the electronic form we choose may be unsuitable to accommodate all of them. Should this be the case, we shall adopt a customized Microsoft Excel sheet.We anticipate that when abstracts do not transparently report methods, we may discard relevant records. In fact, there are no guidelines for reporting signals or SDRs. Furthermore, our exclusion criteria may result in the omission of eligible records: considering as eligible only records whose findings are described as “signals” is an approach that is insensitive to the use of other expressions (e.g. “safety risk”). In principle, contact with original authors would disambiguate those cases in which other expressions have been used, but might render such a broad review infeasible. In the case of contact with regulatory agencies, however, we may ascertain whether communications of, for example, “safety concerns” or “important safety concerns” were considered signals, as long as they reply to our queries. It is possible that we may not receive replies.Furthermore, some publications may use discontinued terminologies to describe ADRs, such as the Coding Symbols for a Thesaurus of Adverse Reaction Terms, which have not been officially reconciled with MedDRA. This may introduce discrepancies in coding terms across terminologies. This is less likely to occur for medicinal products, as WHO-DD are quite comprehensive. However, WHO-DD are insensitive to vaccines; for example, trivalent inactivated influenza vaccine would be coded to “influenza vaccine”. We therefore plan to make this clear in the limitations of the resulting publication. Finally, as concerns the time to signal, the date of entry in VigiBase may be later than the date of receipt of a report to a national pharmacovigilance centre, which may underestimate the time to signal. Between the occurrence of an ADR and the date of entry in VigiBase, there may be a gap ranging from months to several years, thus exaggerating the time to signal. In the interest of transparency, we shall report both dates for each retrieved signal. Also, ADRs may have never been reported to VigiBase in association with some medicinal products, which would impede calculations of the time to signal.Additional file 1. PRISMA-P 2015 ChecklistAdditional file 2. Search strategy