There is increasing recognition that the development of evidence-informed health policy is not only a technical problem of knowledge exchange or translation, but also a political challenge. Yet, while political scientists have long considered the nature of political systems, the role of institutional structures, and the political contestation of policy issues as central to understanding policy decisions, these issues remain largely unexplored by scholars of evidence-informed policy making.We conducted a systematic review of empirical studies that examined the influence of key features of political systems and institutional mechanisms on evidence use, and contextual factors that may contribute to the politicisation of health evidence. Eligible studies were identified through searches of seven health and social sciences databases, websites of relevant organisations, the British Library database, and manual searches of academic journals. Relevant findings were extracted using a uniform data extraction tool and synthesised by narrative review.56 studies were selected for inclusion. Relevant political and institutional aspects affecting the use of health evidence included the level of state centralisation and democratisation, the influence of external donors and organisations, the organisation and function of bureaucracies, and the framing of evidence in relation to social norms and values. However, our understanding of such influences remains piecemeal given the limited number of empirical analyses on this subject, the paucity of comparative works, and the limited consideration of political and institutional theory in these studies.This review highlights the need for a more explicit engagement with the political and institutional factors affecting the use of health evidence in decision-making. A more nuanced understanding of evidence use in health policy making requires both additional empirical studies of evidence use, and an engagement with theories and approaches beyond the current remit of public health or knowledge utilisation studies. In the past two decades there has been a tremendous increase in expenditure on global health research. The Global Forum for Health Research, for example, reported that international funding for this has risen from US$30 billion in 1986 to an estimated $163 billion in 2005 However, within research and policy communities there has been increasing awareness that getting research into policy is not only a technical matter of knowledge translation and exchange, but also a political challenge Outside the field of public health, the discipline of policy studies has long explored the decision-making process, illustrating how different political systems shape the capacity of governments to develop effective policies. Key political system features include the territorial structure of the state – whether it is a unitary  or a devolved  state It is also well established in social and political science that decision-making processes involve tradeoffs between competing interests and values While social and political scientists have long considered the nature of political systems, the role of institutional structures, and the political contestation of policy issues as central to understanding decision making, these issues remain largely unexplored by scholars of evidence-informed policy making. It remains unclear, for example, how the political nature of a given health issue might affect the use of relevant evidence . Nor is there significant understanding of whether particular state structures or institutional bureaucratic arrangements may facilitate or impede the use of evidence for health decision making.To advance our understanding of these questions, we conducted a systematic review of empirical studies that examine the complex interface between politics, policy, and the use of evidence. Previous systematic reviews have been undertaken on aspects of health research utilisation, but these have primarily focussed on technical aspects of knowledge translation including barriers to evidence use, and ways to overcome them. Past reviews have addressed, for example, policy makers’ perceptions of their use of evidence The methods of the analysis and inclusion criteria for the study were specified in advance and are documented in the attached protocol . EligiblHealth polic* AND (research OR evidence) AND (governance OR institution* OR polit*);Evidence-based AND  AND policy AND (governance OR institution* OR polit*)Internet search engines such as Google and Google Scholar were also used to identify material which was not published in journals or available online (e.g. monographs and book chapters). The British Library catalogue was searched to identify relevant titles which met our inclusion criteria. Individual websites were then reviewed for grey literature, selected on the basis of their relevance to the subject and on recommendation from key individuals working in the field. These included the online repositories of the Program in Policy Decision Making at McMaster University, the Centre for Evidence & Policy at King’s College, the WHO Evidence into Policy Network (EVIPNet), and Evidence to Policy Initiative (E2Pi) at the University of California at San Francisco.BMC Health Services Research; Evidence & Policy; Health Policy; Health Policy & Planning; Journal of Health Politics, Policy, and Law; Milbank Quarterly; Social Science & Medicine; Health Research Policy and Systems. The bibliographies of all included text were also reviewed for further relevant citations. Articles were downloaded to an Endnote database and duplicates were removed. All remaining references were then transferred to a Mendeley database to facilitate collaboration during the screening and data extraction phases.Finally, manual literature searches were undertaken in the online archives of the following journals from 1990 until May 2012: Electronic searches yielded 9,730 items. A further 34 items were identified through searches in journal archives, recommendations of colleagues, and through following up of references found in the included articles. After removing of duplicates, 9,257 unique studies remained. The first and second author conducted a preliminary screening of all retrieved studies on the basis of titles and abstracts. 647 articles met the inclusion criteria and were retained. The full texts of these were obtained and assessed for relevance .Given the dearth of specific studies on the politics of evidence-based health policy, we adopted an inclusive approach throughout the selection process. It was decided to include works whose aims were tangential to the central focus of our review, but which presented and discussed relevant findings. However, papers that provided a description of wider political and institutional contexts, but did not explore the ways in which such contexts may have shaped the use of evidence were excluded. We also excluded all contributions that were not supported by empirical data, such as commentaries, letters, and conceptual frameworks. Finally, all three authors discussed and refined the inclusion criteria at several stages of the process and independently reviewed the final list of articles included.The first and the second author extracted data from included studies using a uniform data extraction tool . In addiWhether the study analysed features of political systems that influenced the use (or neglect) of evidence for health policy;Whether the study analysed institutional mechanisms that influenced the use (or neglect) of health research;Whether the study analysed other contextual factors that contributed to the politicisation and contestation of health evidence.The relevant material extracted from the included studies was tabulated and organised according to the three overarching questions noted above. Within these broad thematic areas, collected data were combined according to recurrent issues that emerged from the studies themselves and presented by narrative review After full-text review, 56 studies were selected for inclusion. They focused on a variety of countries, settings, and health issues. Most included studies utilised qualitative methods such as semi-structured interviews and critical analysis of policy documents, although different approaches and sampling criteria were used. Most studies examined single cases of research use in one country, but 12 studies included multiple country comparison or data and 4 studies provided comparative analysis of different cases of research utilisation in the same country. With few exceptions, selected studies can be situated in the field of public health and were primarily driven by practical concerns with health care and health services. Indeed, 35 out of 56 studies were published in health journals, while the majority of the remainder were published in public policy journals. In most contributions the analysis of political and institutional elements was often subordinate to other research objectives, such as the identification of technical barriers to, and facilitators of, the use of evidence or descriptions of the ways in which evidence was used to inform specific health policies or programmes. Only 6 studies were judged to have explicitly engaged with political theories or concepts The first of the key questions we set out to explore is whether any links could be found between the use of evidence for health policy and key features of different state political systems . We identified 4 studies that explicitly addressed this question, all of which were concerned with the implications of centralised governance. One study explored decision-making processes at the UK National Health Service (NHS) prior to the reforms of the late 1990s Another study examined the failure of the British government to handle risk communication during the public health crisis of bovine spongiform encephalopathy (BSE) in the late 1980s. Having analysed the political and institutional context in which decisions about scientific evidence were made, this study found that a centralised system in which government agencies control expert advice with little public oversight is more vulnerable to the pressure of expert interest groups in decisions around evidence use We found no studies that systematically explored the effects of democratisation on the use of evidence, but the findings of some studies which noted the importance of changes in regime are relevant to this question. Two studies reported that the shift to parliamentary democracy in South Africa in 1994 created a new governance model that was more open to the uptake of research findings, as academic researchers were appointed to managing positions in the National Department of Health and new research institutes were established to support policy making Our second area of analysis was to identify empirical studies of how different institutional mechanisms  shape the use of health evidence. While more studies were identified which addressed this issue than the theme of political systems, many studies cut across a wide range of topics, providing a variety of disparate findings.One study on policy for health inequalities in the UK, for example, found that the division of responsibilities within government bureaucracies limited the use of evidence, arguing that “individual civil servants are compelled to focus on small, specific areas of policy activity, making it extremely difficult for them to engage with ideas beyond their immediate area of responsibility” Institutional path-dependency was found to be another important hurdle to unbiased or systematic evidence use. A study of WHO’s management of the 2009 H1N1 pandemic suggested that previously chosen policy responses are likely to be prioritised over alternative evidence-informed options, especially when the health issue is surrounded by scientific uncertainties Another institutional challenge noted in three studies was how high turnover of staff in health departments could undermine the systematic use of evidence for policy or planning We found a number of studies which included some institutional analysis of bodies outside government departments of health which are tasked with facilitating evidence utilisation and knowledge brokering. A comparative study of nine Latin American and three European countries, for example, found that the use of evidence from economic evaluations for health policy decisions was increased in countries  which had formally-mandated organisations to provide such evidence Works focussing on non-governmental evidence-providing bodies also pointed to how personal connections between knowledge brokers and decision makers can be an important factor increasing the uptake and use of evidence in both high-income Our final theme of analysis was to explore other contextual factors that may influence and politicise the use of evidence in health policy making. A set of studies were identified that analysed how existing normative positions including: values and moral convictions Several further studies noted how the alignment of health issues with existing political priorities in a country can affect the use of evidence. A study on health policy in China reported that research findings on the impact of health expenditure on rural poverty had a direct impact on policy because they reflected already existing concerns of policy-makers about economic growth and poverty reduction An article from Canada further suggested that policy decisions about the content of an intervention may be more amenable to the influence of research than broader or more conceptual decisions with multiple social implications Several studies from lower-income settings noted that when a health issue is particularly important to international donors, this too can impact on the use of evidence, including the ways in which research is prioritised and conducted, and how findings are interpreted and used to inform policy decisions. Donors tended to promote interventions with strong evidence bases, but they do so in ways that may neglect local context, needs and capabilities Finally, the tensions between national and international concerns and the influence of national as opposed to international evidence was also a theme that appeared in some included studies. A study from the Netherlands found that there was a growing reliance on international rather than national data, raising concerns over the relevance of such research to specific country needs, the ease of access to findings, and the perceived legitimacy by local policy makers This review arose from recognition of the importance of political factors in shaping the use of evidence to inform health policy processes, yet the limited explicit engagement with relevant theories in the literature on evidence-informed health policy. We structured our analysis around three analytical themes emerging from social and political sciences as explaining policy outcomes: the features of state political systems, the institutional structures and arrangements of bodies using evidence, and the politicisation of specific issues. A stand-out finding from our review was that little empirical work has been done explicitly analysing these issues, with many included studies dealing with them only indirectly.The systematic review approach, however, enabled us to identify the political and institutional factors that have so far been identified in the existing literature as important in shaping the uptake of evidence for health policy making. These factors include concentration of power and political centralisation, levels of democratisation, institutional mechanisms and processes, turnover of staff in government bodies, the influence of donors and external organisations, the pressure of wider policy strategies and political cultures, as well as the alignment of evidence with predominant values or existing political agendas. Results also indicate that processes of evidence-based policy making often involve a complex interplay of these factors, both at the national and international level.Nevertheless, our understanding of these issues remains patchy and inconclusive. The selected studies do not constitute a clearly defined body of research, developed around shared debates, research questions or theoretical approaches. While many studies relied on theories of knowledge utilisation, these were generally applied to support and guide empirical work rather than using empirical works to test or refine specific theories. Most notably, despite the fundamentally political nature of decision making processes, the extensive literature on political institutions, and the highly contested nature of many health issues, very few works could be identified which explicitly applied policy science perspectives to understand the use of evidence in health policy making. As a result, the analysis of political and institutional influences was limited, with no significant consideration of key issues such as the influence of party systems, the relations between different branches of government, power imbalances and hierarchies, and questions of political legitimacy.Furthermore, the highly contextual nature of the policy process points to the need for comparative case study analysis to facilitate theory development Finally, we conducted this literature review according to systematic, and therefore replicable, criteria for data collection and inclusion Despite these limitations, our review contributes to improved recognition of the political dimension of health evidence utilisation, and can thus stimulate critical thinking about current policy debates. In particular, the perceived need to ‘bridge the gap’ between research and policy has encouraged the development of technical recommendations to facilitate research uptake; with the universal value of using the research often taken for granted. For example, some consensus has emerged in recent years about the benefits of closer interactions between researchers and policy-makers, from the early stages of research processes Furthermore, our approach raises concerns about the public health community’s tendency to depoliticise the idea of evidence use, evaluating policy making processes simply by whether, how much, or how quickly pieces of evidence are taken up by policy makers. Such an approach can obscure the complexity of the policy making process in which policy makers must evaluate competing social outcomes and value systems in ways which are accountable to local populations. Simply calling for policy to be ‘evidence based’ encourages decision makers to prioritise those issues where a large or more coherent body of evidence is available  as opposed to more complex social and structural interventions to prevent ill health for which it is not so easy to identify direct causal mechanisms or gather evidence of immediate effect Our review also suggests that an unreflective acceptance of over-simplified concepts of ‘evidence based policy’ is not conducive to good governance practices. For example, political pressures may encourage a selective use of evidence as a rhetorical device to support predetermined policy choices or ideological positions, or may delay decision-making on contentious issues while less contentious topics with clearer, uncontested evidence bases are followed. Such biases are likely to be amplified when there is a lack of institutional capacity or structures able to provide competent and independent scientific advice. However, empirical studies indicate that even institutional bodies that operate according to the most rigorous procedures may be vulnerable to distortions and/or the influence of interest groups This review identified a number of key issues at the interface of health policy, politics, and evidence use. With a greater awareness of the politics of evidence-informed health policy, more specific and explicit questions must be asked about the effects of different political factors impacting on evidence use in policy making and their interdependencies. What kind of institutional arrangements are more likely to facilitate a ‘good’ use of evidence in different political contexts? Are decisions seen as more legitimate if evidence is used to inform decision-making? How can these be evaluated? What can be done to reduce the biased and opportunistic use of evidence for political ends? To what extent can evidence-based guidelines promote policy change across different political and institutional settings?Improved understanding of questions such as these requires the in-depth analysis of case studies of research uptake, with careful consideration of the institutional and organisational arrangements that may influence the selection and use of evidence. The work of Kogan and Henkel in the 1980s, for example, undertaking a seven year evaluation of the UK Department of Health’s use of evidence Table S1Data extraction form.(DOCX)Click here for additional data file.Table S2Characteristics of included studies.(DOCX)Click here for additional data file.Text S1Research protocol.(DOCX)Click here for additional data file.Checklist S1PRISMA checklist.(DOC)Click here for additional data file.


This paper reports the rationale and plan for this five-year knowledge translation research program. The overarching aims of the program are threefold: to improve outcomes for people with traumatic brain injury; to create a network of neurotrauma clinicians and researchers with expertise in knowledge translation and evidence-based practice; and to contribute knowledge to the field of knowledge translation research. The program comprises a series of interlinked projects spanning varying clinical environments and disciplines relevant to neurotrauma, anchored within four themes representing core knowledge translation activities: reviewing research evidence; understanding practice; developing and testing interventions for practice change; and building capacity for knowledge translation in neurotrauma. The program uses a range of different methods and study designs, including: an evidence fellowship program; conduct of and training in systematic reviews; mixed method study designs to describe and understand factors that influence current practices ( It is defined as injuries caused by external mechanical force to the head, injuries. Incideninjuries. There ainjuries.TBI can result in long term or lifelong physical, cognitive, behavioural, and emotional consequences. As a result of these consequences, TBI is one of the most disabling injuries and the Worldwide, much research is conducted relevant to TBI and with the potential to improve outcomes for people with TBI. HoweverThe care of people with TBI includes many disciplines because patients often have a long journey of care through pre-hospital, hospital, rehabilitation, and community settings-18. At thttp://www.netprogram.org.au) commenced, funded by the Victorian Government’s Transport Accident Commission and Department of Innovation Industry and Regional Development, Australia. This five-year program provides opportunity to develop and sustain a coordinated collaborative approach to KT for TBI in Australia. The overall aims of the program are: to improve outcomes for people with TBI; to create a network of neurotrauma clinicians and researchers with expertise in KT and evidence-based practice; and to contribute knowledge to the field of KT research. The program includes a range of integrated activities in the knowledge-to-action-cycle[In November 2009, the Neurotrauma Evidence Translation (NET) program , and building capacity to conduct research synthesis. The theme builds on the work of the Global Evidence Mapping Initiative (http://www.evidencemap.org)[For research evidence to be effectively implemented in clinical practice, it first needs to be synthesised and summarised and then made available in formats that are useful and relevant to the local setting. Theme omap.org), which iTheme one of the NET program has two main components: an Evidence Fellowship Program, and the development of locally relevant best practice recommendations.Knowledge of current research evidence combined with clinical experience and patient preference is pivotal to evidence-based practice. To support evidence-based practice, clinicians need skills to search for, acquire, appraise, and interpret research findings. Barriers to evidence-based practice for clinicians have been well-documented, and include a lack of time, insufficient resources, and limited skills in accessing and applying research. FellowsThe objectives of the NET Evidence Fellowship Program are to:1. build skills and capacity for evidence-based practice within the neurotrauma community through mentoring clinicians to undertake systematic reviews;2. encourage fellows to become future leaders and knowledge champions;3. produce systematic reviews in priority neurotrauma topics to inform clinical practice.e.g., Cochrane Collaboration author training); one-on-one mentoring and training by an experienced systematic reviewer and trainer with skills in searching, critical appraisal, interpretation of results and evidence-based decision making; and the provision of peer and administrative support.To inform the design of the NET Evidence Fellowship Program, a systematic search was conducted in MEDLINE and EMBASE from 1996 to August 2011 to identify literature that described and evaluated evidence-based practice skill-development programs. Relevant papers were reviewed regarding their program concept, results, and experiences. The program was designed to incorporate the main findings from the systematic review and includes: recruitment of clinicians by targeting specific networks or recommendations by referral; access to training workshops  between the research settings of the original studies and the site of implementation[When evidence has been synthesised, and a reliable body of evidence exists, then efforts need to focus on converting the evidence into formats that are useful to end-users. The secentation,31 may iOur process therefore encompasses the following steps: identifying current, high quality clinical practice guidelines (CPGs) and extracting recommendations; selecting strong recommendations in key clinical management areas; updating evidence and creating evidence overviews; discussing evidence and producing agreed ‘evidence statements’; discussing the relevance of the evidence with local stakeholders; and developing locally applicable actionable best practice recommendations, suitable for use as the basis of quality indicators. The process is reported in full elsewhere.This project aims to develop recommendations in three areas of practice, relevant to TBI, in acute and rehabilitation phases of care. To date, the process has been completed for the management of mTBI in Australian emergency department (ED) settings,33.Once evidence-based best practice has been agreed, current practice needs to be determined so as to identify gaps between evidence and practice and establish areas most in need of change. In addiTBI is a frequent cause of presentation to EDs, and 70% to 90% of these are classified as mild,42. The To explore current practice in the ED management of mTBI we triangulated data derived from the following methods: a literature search identifying previous studies on mTBI management in Australian EDs; an audit of management of mTBI in two Victorian EDs; and qualitative interviews with ED staff and directors in a purposeful sample of Victorian EDs to explore reported management. Our descriptions of current practices were compared with agreed local best practice, as determined in theme one,33, so aInterviews with ED staff and directors also explored the individual, team, organisational, and system factors that may influence management and implementation of the agreed local best practice recommendations. We interviewed 42 participants (staff and directors) across 13 EDs until data saturation was reached. Sites we.g., baclofen, botulinum toxin A) and non-pharmacological interventions . Currently, little is known about the nature of current management of spasticity following TBI in rehabilitation or community settings.Skeletal muscle spasticity is a major physical complication resulting from TBI. There is limited epidemiological data regarding the prevalence of spasticity following TBI, however it has been reported to affect more than one in ten patients with severe TBI. Spastici.e., the factors that influence the actual change process).We plan to explore current practice in the management of spasticity through conduct of a survey of Australian medical and allied health practitioners who manage spasticity following TBI. A random sample of practitioners working in rehabilitation and community care settings will be invited to complete a survey eliciting information about their assessment and treatment of spasticity following TBI. Our estimates of current practice will be compared with systematic review evidence supporting the use of interventions for managing skeletal muscle spasticity following TBI, as determined in theme one, so enabOnce the factors influencing practice and practice change have been identified, the next steps are to develop a KT intervention aiming to address these factors, and to test its effectiveness. We aim Theme three aims to improve outcomes for patients with mTBI presenting to the ED through implementation of the locally relevant best practice recommendations developed in theme one. More specifically, the objectives are:1. to systematically develop a targeted, theory-informed, and evidence-based implementation intervention to increase uptake of evidence informing the ED management of mTBI into practice;2. to test in a cluster randomised trial (CRT) the effectiveness of this intervention in changing practice compared with passive dissemination of the recommendations;3. to conduct a process evaluation alongside the CRT to understand the pathway of change.A systematic process to map intervention components to identified determinants of practice change will be used in developing the targeted theory-informed intervention,52,56.We will conduct a CRT to test whether the intervention is effective in improving the uptake of key evidence-based recommendations in the management of mTBI. Hospital EDs will form the clusters. A randomised design is the preferred design to evaluate the effectiveness of an intervention because it minimises bias in estimating intervention effects,58. In tThe overarching and supporting theme of the NET program is to build sustained capacity and infrastructure for KT in TBI, therebyBuilding capacity and developing infrastructure requires investment in resources and structures, such as innovative training, skill development and support for practitioners, and sustained commitment from clinical leaders. Cross sector relationships and partnerships are needed between researchers, clinicians, policy makers, and healthcare consumers to build forums for exchange. To inform this, we need evaluation of what works to implement research into practice; for whom, why, and at what cost. Theme four will harness activities and networks from themes one to three to establish resources and systems, develop a workforce with KT skills, and foster a sustainable neurotrauma KT structure and culture. Specific functions under theme four include the coordination and hosting of three KT conferences over the course of the program, stakeholder dialogue events, and brokerage of relationships across disciplines and sectors through advisory structures and shared prioritisation.The NET program has a program-wide multidisciplinary steering committee, which provides strategic direction to the program, offers practical support towards achieving the overarching aims of the program, and fosters links between the NET program and its identified stakeholder groups—the neurotrauma clinical community, consumers, policy makers, and funders. A number of networks and collaborations have been formed spanning Australia, Canada, USA, and UK, and these teams are exploring new neurotrauma KT initiatives that build upon the activities in the NET program.The NET program is a coordinated approach to KT in TBI in Australia. The program comprises a series of interlinked projects spanning varying clinical environments and disciplines, anchored within four themes representing core KT activities: reviewing research evidence; understanding practice; developing and testing interventions for practice change, and building capacity for KT in neurotrauma. The program aims to contribute to improving care for patients with TBI in Australia, and to contribute to the science of KT research.CPG: Clinical Practice Guideline; CRT: Cluster Randomised Trial; ED: Emergency Department; (m)TBI: (mild) Traumatic Brain Injury; NET: Neurotrauma Evidence Translation; KT: Knowledge Translation.Denise O’Connor is an Associate Editor for Implementation Science. The authors declare they have no other competing interests.Sally Green and Russell Gruen conceived of the program and wrote the original grant proposal. Joanne McKenzie and Denise O’Connor contributed to sections of the original grant proposal. Marije Bosch wrote the first draft of the manuscript and prepared the revised versions. All other authors critically reviewed and contributed to draft revisions, and read and approved the final version of the manuscript.


Here we present our attempt at off pump HeartMate II left ventricular assist device (LVAD) implantation using the anticoagulant bivalirudin in a patient with heparin induced thrombocytopenia, which resulted in thrombosis within the LVAD device. This required that our procedure be converted to on pump, and a new HeartMate II LVAD device to be implanted. In our view, this thrombotic event may have been caused by a number of factors that include bivalirudin’s (1) short half-life of about 20 minutes, (2) decreased activity with blood stasis, (3) inability to prevent clot propagation, and (4) uncertainty with real-time monitoring of therapeutic levels. To prevent future thrombotic events, it may be beneficial to immediately deair the LVAD device prior to the coring of the left ventricle during off pump LVAD placement. In addition, a solution other than blood may be used for priming. If blood is used for priming of the LVAD device, the duration of blood stasis should not exceed 20 minutes when bivalirudin is being used for anticoagulation. Furthermore, this case emphasizes the importance of having a backup LVAD device available and ready to use during surgical procedures. Left ventricular assist devices (LVAD) can be implanted with the assistance of cardiopulmonary bypass (on pump), or without cardiopulmonary bypass (off pump). We have recently published our institutional experience with off pump placement of the LVAD. The dirWe present our attempted case with off pump placement of a HeartMate II LVAD using bivalirudin for anti-coagulation that resulted in clot formation inside the device. This required urgent conversion of the procedure to be completed with cardiopulmonary bypass (CPB) and a new HeartMate II LVAD device was later implanted successfully.A 71-year-old Caucasian female with heart failure and a history of heparin induced thrombocytopenia type 2 (HIT) presented for placement of an off pump HeartMate II. Her baseline activated clotting time (ACT) was 124 seconds. A 50 mg bivalirudin bolus was given followed by continuous infusion of bivalirudin titrated to 1.25 mg/kg/hr to achieve an ACT of 326 seconds after induction of general anesthesia and insertion of invasive lines. We have previously described our off pump LVAD implantation technique[This is our attempted case with off pump LVAD placement reported with bivalirudin, which resulted in significant LVAD thrombosis. In this case, we were able to titrate bivalirudin to increase the ACT to the suggested goal of >300 seconds-8. HowevThe thrombosis may have occurred due to the amount of time that passed (about 20 minutes) between the retrograde priming of the device with blood and the coring of the left ventricle. The timing is important because the half-life of bivalirudin is only 25 minutes (compareAnother plausible mechanism responsible for this clot may be because of bivalirudin’s reversible binding kinetics with thrombin and proteolytic cleavage of bivalirudin by thrombin. Proteolytic destruction by thrombin plays a major role in bivalirudin elimination, and this places areas of blood stasis at high risk of having subtherapeutic bivalirudin levels. Accordingly, several case reports exist of thrombus associated with bivalirudin in CPB venous reservoirs, in the CPB circuit after or near the termination of the CPB procedure, and post cardiotomy ECMO,10. It iBivalirudin is unable to prevent clot propagation as effectively as heparin. Nielson et al. have conducted in vitro studies that demonstrate that direct thrombin inhibitors have similar efficacy compared to heparin in initiation of clot formation, but they are not as effective as heparin in preventing clot propagation. Furthermore, ACT utilization to monitor a safe level of anti-coagulation may be grossly inadequate, because ACT only measures clot initiation, and not clot strength or clot propagation. AccordiFurthermore, no guidelines exist regarding the optimal dosing or regarding the most prudent method of monitoring the anticoagulation of any of the direct thrombin inhibitors during surgery. RecentlIt is important for the perioperative team to understand that different implantation techniques can have technical limitations. To prevent this complication in the future and in a patient with HIT, the deairing/priming of the LVAD should be done immediately prior to cannulation of the left ventricle. We also need to be aware of bivalirudin’s pharmacologic properties. A different solution can be used for LVAD priming as opposed to blood. In addition, this case also points out the importance of having a backup LVAD available during surgical procedures.Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.LVAD: Left ventricular assist device; HIT: Heparin induced thrombocytopenia; CPB: Cardiopulmonary bypass; ACT: Activated clotting time.The authors declare that they have no competing interests.HA conceived of the study, and helped with the drafting and proofreading of the manuscript. RB, OM, and GD participated in background literature review, drafting, and proofreading of the manuscript. CS helped conceive the study, emphasized the significance of this topic, and helped proofread the manuscript. All authors read and approved the final manuscript.


Accelerating Progress in Obesity Prevention — Solving the Weight of the Nation  report on e Nation , the urgn Making , in the n Making  and a coBridging the Evidence Gap report explains that timely and credible evidence is needed to help decision makers decide what to do and understand how to do it, distinguish actions that are likely to be effective from those that are not, justify particular actions in high-risk populations, quantify likely effects, estimate costs and cost-effectiveness, set priorities regarding specific outcomes, determine who benefits, and anticipate potential problems. The report sponsors — Kaiser Permanente, The Robert Wood Johnson Foundation, and the Centers for Disease Control and Prevention — were motivated by their perception that effective approaches to obesity prevention were proving difficult to identify, creating a risk that ongoing efforts to address the problem would be ill-conceived or haphazard.Decisions about obesity prevention are being made daily in communities, states, and countries worldwide. The Bridging the Evidence Gap report and related summaries, as well as the presentations from 2 workshops convened by the committee, are available from IOM at www.iom.edu/Reports/2010/Bridging-the-Evidence-Gap-in-Obesity-Prevention-A-Framework-to-Inform-Decision-Making.aspx.Below we describe the evidence framework that resulted from the study committee’s consensus process and provide some examples of how it can be applied to evaluate existing evidence and inform the generation of new evidence. The full Early in its deliberations, the study committee decided that it would be essential to understand how various forms of evidence are generated and used in obesity prevention efforts and are related to core concepts in the broader sphere of evidence-based public health (EBPH) ,3. This Described by Kohatsu et al, EBPH is a process of integrating science-based interventions with community preferences to improve the health of populations . As in eTo align with the core concepts of EBPH, approaches and tools should be geared to the types of research and practice issues that arise in public health ,7. For eAlthough to date few approaches to EBPH have been systems-based, evidence gathering and use in the L.E.A.D. framework has a systems perspective . PreciseThe L.E.A.D. framework adapts an EBPH typology recommended by the International Obesity Task Force ,9 for spThe L.E.A.D. framework identifies several different types of evidence and study designs that can be useful for informing decisions about obesity prevention and provides resources and explanations in the report narrative and appendices. L.E.A.D. does not imply lowering standards for the quality of evidence used in public health compared with medicine. Rather, it introduces the concept that broader and different standards are needed to account for the complexity and practicalities associated with issues that arise in obesity prevention and other public health problems . Evidence sources may be quantitative or qualitative or a combination of both and may come from academic research, program evaluations, surveys, polls, reports, or policy documents related to obesity or to other public health issues from which parallels can be drawn. Specific study designs and methods identified in the report include experiments and quasi-experiments, qualitative research, mixed methods, evidence synthesis methods, parallel evidence, and expert knowledge. The point is to be systematic but much more inclusive when determining what constitutes useful evidence related to a particular question. Evidence quality is then to be evaluated by standards appropriate to that type of evidence rather than by a single standard. Examples of existing criteria for assessing quality of evidence from these different methods are provided.One way that EBPH differs from EBM is that it relies less on randomized controlled trials and more on approaches that assess external validity. Study design cannot be the sole criterion for whether evidence is useful. A randomized controlled trial is the most rigorous design for hypothesis testing  but is nGuide to Community Preventive Services framework for translating evidence into recommendations, the RE-AIM framework  for translating research into practice, the Health Canada risk assessment and management framework, the International Obesity Task Force obesity prevention portfolio approach for selecting a set of interventions, and the Green and Kreuter framework for identifying program components and interventions   a statement of the question, 2) a transparent description of the strategy used to locate the evidence, 3) a table reporting the evidence, and 4) a summary of the evidence organized as answers to the EBPH-derived questions . Becausetching”) ,15-19.In addition to the systems perspective, recognizing opportunities to generate new evidence is also recommended as a theme of the L.E.A.D. framework. Such opportunities might arise at any stage of the process. Generation of new evidence is critical not only because of the dearth of suitable evidence about obesity-relevant environmental and policy changes but also to keep the evidence base current with the dynamics of the obesity problem. The “why,” “what,” and “how” questions in Kaiser Permanente Healthy Eating Active Living Community Health Initiative (HEAL-CHI)BackgroundObesity is a major health problem among both adults and children in the United States ,21. In CContextReversing the obesity epidemic requires a sustained effort at multiple levels, including environmental and policy changes . Since cEvidence BaseGuide to Community Preventive Services has made a positive recommendation  endation , on the endation  that hasAs recommended in the L.E.A.D. framework, an approach to increasing the evidence base is to evaluate community interventions that either attempt to implement existing programs such as CATCH or create new programs developed by schools and communities themselves. Although these evaluations do not use experimental designs, they follow the recommendations in the LE.A.D. report that advocate for taking advantage of all opportunities to increasing the evidence and exploring alternative, nonexperimental research designs.Lessons and Future DirectionsThe HEAL-CHI evaluation used a logic model approach to assessing intervention impact that combined estimates of the reach and strength of the interventions with population-level measures of physical activity, nutrition, and overweight . In particular, we assessed whether there were significant positive population-level changes where “high-dose”  interventions were implemented. The information about reach and strength came from independent assessments of the number of people exposed and the intensity of the interventions. For example, one high-dose intervention was an after school physical activity program that one-quarter of all children participated in that added 20 minutes per day of moderate to vigorous physical activity. Results indicated that in almost half of the cases (4 of 9) where high-dose interventions were implemented, significant positive changes favored the intervention. For example, in the community implementing the after-school physical activity program, the percentage of seventh graders doing vigorous physical activity at least 20 minutes per day increased from 61% to 67%, while the percentage in comparison communities declined from 56% to 51%.ImplicationsThe HEAL-CHI initiative used L.E.A.D. thinking at several points — both in applying criteria for interventions and in evaluating the results. Our experience suggests that L.E.A.D. may be a useful approach for incorporating evidence into community-based obesity prevention initiatives. The L.E.A.D. framework encourages both taking a broader view of the existing evidence and using an array of designs in doing evaluations that add to the evidence base. If the L.E.A.D. framework is widely adopted, publishing results such as those we found in the HEAL-CHI initiative in peer-reviewed publications will be easier.Bridging the Evidence Gap report directs recommendations to decision makers in the policy and programmatic arenas as well as to those who fund, generate, and publish evidence about obesity prevention and other complex public health challenges. Central themes are to apply the L.E.A.D. framework as a guide in the use and generation of evidence and to incorporate systems-thinking into research activities. The report also recommends the development of resources to support evidence-based public policy decision making and research, including researcher training, compendiums of knowledge, registries of implementation experience, and guidance on standards for evidence evaluation where they are lacking. The need for a public-private consortium to take up dissemination, support for, and further development of the L.E.A.D. framework is emphasized.The Bridging the Evidence Gap report was released, it has gained visibility among potential users. The report page on the IOM website has generated more than 17,000 page views. The L.E.A.D. framework has been presented at national and international meetings and cited in journal articles and policy documents. Scanning approximately 40 identified citations indicates that most have involved referencing the report in support of the importance of developing comprehensive multistakeholder and multisectoral strategies, taking a systems perspective, or using expanded approaches to evidence-gathering or choice of study designs. Applications of the framework reflected in published documents include a CDC Division of Nutrition, Physical Activity, and Obesity fact sheet that explains how the framework relates to potential uses of their research and practice-based initiatives, evidence sources, and guidance documents (In the approximately 2 years since the ocuments ; adaptatocuments ; use of ocuments ; use of ocuments ,34; and What does this mean for obesity prevention and for advancing appreciation for the science and practice of EBPH? The answer depends on further use of frameworks such as L.E.A.D. In an ideal sense, L.E.A.D. could become a transformative and integrative EBPH paradigm and tool, as intended by the IOM study committee that developed it. The transformational aspect is the positioning of evidence needs in a public health context and demonstrating that rigor and relevance can be achieved using EBPH concepts and tools. Advances in obesity prevention will depend in part on articulating the value of multiple and varied types of information for answering policy and practice questions. If widely adopted and used, L.E.A.D. could become a critical component of identifying and using evidence-informed strategies for achieving national health objectives . Such us


P < 0.05), while there was no significant association between the spleen stiffness and spleen index/presence of esophageal varices in CHC patients. The area under the receiver operating characteristic curve based on the spleen stiffness was 0.80. In conclusion, spleen stiffness significantly correlates with the presence of ascites but not esophageal varices in CHC patients.Although spleen stiffness has recently been identified as potential surrogate marker for portal hypertension, the relationship between spleen stiffness and portal hypertension has not been fully elucidated. We attempted to determine the relationship between the liver or spleen stiffness and the presence of ascites or esophageal varices by acoustic radiation force impulse (ARFI) imaging. A total of 33 chronic hepatitis C (CHC) patients  were enrolled. We evaluated the relationship between the liver or spleen stiffness and indicators of portal hypertension as well as clinical and biochemical parameters. Fourteen healthy volunteers were used for validating the accuracy of AFRI imaging. The liver and spleen stiffness increased significantly with progression of liver disease. A significant positive correlation was observed between the liver and spleen stiffness. However, spleen stiffness, but not liver stiffness, was significantly associated with the presence of ascites ( In cirrhotic patients with portal hypertension, increase of the spleen size is due mainly to tissue hyperplasia associated with a parallel increase of the splenic blood flow, which probably participates in the pathogenesis of portal hypertension . HoweverARFI imaging is a new elastographic technology integrated into conventional B-mode ultrasonography. It is an inexpensive and noninvasive modality, conveniently performed in patients who are not suitable candidates for MRI. ARFI imaging allows quantification of the shear-wave velocity (SWV) (m/sec), which has been shown to be correlated with the liver fibrosis stage –13. The Thirty-three consecutive hepatitis C patients  with chronic hepatitis or liver cirrhosis seen at our institution were enrolled. The control group, which was used for validating the accuracy of ARFI imaging, was composed of 14 healthy volunteers . The median age was lower in the control group than in the chronic hepatitis group or liver cirrhosis group. The inclusion criteria for the controls were at the age of 18 years or older, no history of chronic liver disease, and normal serum liver enzyme levels at the time of enrollment.Laboratory tests, including the serum bilirubin and albumin, platelet count, prothrombin time, and serum markers of fibrosis , were performed in all patients within 1 month from the beginning of the study. In all patients, a fiberoptic upper gastrointestinal endoscopy was performed to check for the presence of esophageal varices and abdominal ultrasonography to check for the presence of ascites and determine the spleen index. Esophageal varices were evaluated by the endoscopist without knowledge of the data of liver and spleen stiffness measurement. Calculation of the median liver and spleen stiffness was possible in all subjects. Liver cirrhosis was diagnosed by the predictive model of cirrhosis in patients with CHC based on standard laboratory tests . This stLiver and spleen stiffness were measured by ARFI imaging in Virtual Touch Tissue Quantification using an ACUSON S2000 apparatus . One experienced sonographer operated the apparatus. ARFI imaging involves targeting an anatomic region to be interrogated for elastic properties with the use of a region-of-interest (ROI) cursor while performing real-time B-mode imaging. Transmission of longitudinal acoustic pulses leads to tissue displacement, which results in shear-wave propagation away from the region of excitation. The SWV is measured within a defined ROI  by using ultrasound tracking beams laterally adjacent to the single push beam. The shear-wave propagation velocity is proportional to the square root of the tissue elasticity. Results are expressed in meters per second. We used a curved array at 4 MHz for B-mode ARFI imaging. We measured the liver stiffness in the right liver robe, 2-3 cm below the liver capsule, via an intercostal approach, and the spleen stiffness in the lower pole of the spleen, 2-3 cm below the spleen capsule, also via an intercostal approach. In each patient, 5 valid ARFI imaging measurements were performed in the liver and the spleen based on previous reports , 13, 15.H-test followed by Mann-Whitney's U-test with post-hoc Bonferroni's correction. Analysis of variance for comparison of two groups was performed by Mann-Whitney's U-test. Comparisons of percentages between the ascites and non-ascites groups or between the esophageal varices and non-varices groups were performed using Fisher's exact test. The correlations between the liver stiffness and the spleen stiffness or between the spleen index and spleen stiffness were assessed by calculation of Spearman's correlation coefficient. We assessed the diagnostic performance of ARFI imaging by receiver operating characteristic curve (ROC curve) analysis. The ROC curve represents the sensitivity versus (1-specificity) for all possible cut-off values. Area under the ROC curve (Az) and 95% confidence intervals of the Az values were calculated. Differences were regarded as significant when the P values were less than 0.05.All data were presented as median and range. Analysis of variance for comparison of more than two groups was performed using the Kruskal Wallis The clinical and biochemical characteristics of the study subjects are listed in P values of the significant differences between the groups were as follows: control versus cirrhosis (P < 0.001); chronic hepatitis versus cirrhosis (P < 0.001).Determination of liver stiffness was possible in all volunteers and patients. There were no subjects who met the definition of unreliable measurements of liver stiffness. P values of the significant differences between the groups were as follows: control versus cirrhosis (P < 0.001); chronic hepatitis versus cirrhosis (P = 0.002). Determination of spleen stiffness was possible in all volunteers and patients. There were no subjects who met the definition of unreliable measurements of spleen stiffness. P < 0.01).In the overall subject population, no significant correlation was found between the spleen stiffness and spleen index.P < 0.05).The median liver SWV (range) was 2.54 m/sec (IQR 2.02–3.30 m/sec) in the presence of ascites and 2.28 m/sec (IQR 2.12–2.50 m/sec) in the absence of ascites. The liver stiffness did not differ between the groups with and without ascites. On the other hand, the median spleen SWV (range) was 3.6 m/sec (IQR 3.24–3.80 m/sec) in the presence of ascites and 2.90 m/sec (IQR 2.78–3.28 m/sec) in the absence of ascites . The splThe median liver SWV (range) was 2.39 m/sec (IQR 1.89–2.63 m/sec) in the presence of esophageal varices and 2.40 m/sec (IQR 2.12–2.90 m/sec) in the absence of esophageal varices. Also, the median spleen SWV (range) was 3.41 m/sec (IQR 3.04–3.66 m/sec) in the presence of esophageal varices and 3.18 m/sec (IQR 2.90–3.63 m/sec) in the absence of esophageal varices. The liver stiffness and spleen stiffness did not differ between the groups with and without esophageal varices.P = 0.012) and spleen stiffness (P = 0.012) were found to be significantly different between the cirrhotic patients with and without ascites. The clinical characteristics of the patients with cirrhosis are shown in The liver stiffness cut-off value of 2.52 m/sec had a negative predictive value (NPV) of 50.0%, positive predictive value (PPV) of 80.0%, sensitivity of 53.3%, specificity of 77.8%, accuracy of 62.5%, positive likelihood ratio (+LR) of 2.40, and negative likelihood ratio (–LR) of 1.67. In contrast, the spleen stiffness cut-off value of 3.34 m/sec had an NPV of 63.6%, PPV of 84.6%, sensitivity of 73.3%, specificity of 77.8%, accuracy of 75.0%, +LR of 3.30, and −LR of 2.92. The major findings of our study were that the spleen stiffness, but not the liver stiffness, was correlated with the presence of ascites and that the spleen stiffness did not correlate with the presence of esophageal varices in chronic hepatitis C patients. We also showed that ARFI imaging is an excellent modality for measurement of not only the liver stiffness but also the spleen stiffness, even in the presence of ascites. Our study is the first report until now to evaluate the association between spleen stiffness and the presence of ascites. Ascites can be relatively easily detected by conventional abdominal ultrasonography. However, the finding is of potential clinical significance in view of the possibility of predicting the development of ascites in chronic liver disease by measuring the spleen stiffness, even before ascites can be detected by conventional abdominal ultrasonography. Specifically, ARFI imaging might be useful to predict the development of ascites in posttransarterial chemoembolization by measuring the spleen stiffness before transarterial chemoembolization. In addition, in the event of difficulty in detecting the presence of ascites by conventional ultrasonography due to miscellaneous reasons, such as noticeable obesity or posthepatic resection, ARFI imaging may be useful for suggesting the presence of ascites by measuring the spleen stiffness in an inexpensive and noninvasive way. Previous studies reported that the rates of unsuccessful measurements for liver and spleen stiffness using ARFI imaging were 2.8%  and 4.8%One of the possible reasons for the finding that the liver stiffness was not significantly correlated with the presence of ascites is as follows. Portal hypertension develops as a result of an increase in intrahepatic resistance to portal blood flow due to the profound morphologic changes in the liver characterized by fibrosis and regenerative nodules compressing the sinusoids, which lead to vascular obliteration, activation of the hepatic stellate cells, and vasoconstriction due to intrahepatic nitric oxide deficiency and enhanced vasoconstrictor activity . In the One of the possible reasons for the positive correlation between the spleen stiffness and presence of ascites is as follows. The anatomic features and microcirculation of the spleen are well characterized. Splenic tissue is composed primarily of red pulp tissue and, to a lesser degree, white pulp. Within the red pulp, blood is received by the penicillar arterioles, which open directly into the venous sinuses and trabecular vein. Blood exits through the splenic vein into the splanchnic venous circulation. White pulp is composed of a central artery surrounded by lymphoid tissue. Penicillar arterioles originate from the central arteries outside the white pulp and drain into the venous sinuses and the red pulp . Thus, pNo significant correlation was found between the presence of esophageal varices and the liver stiffness or spleen stiffness in our study. This was probably because esophageal varices are only one of the components of collateral circulation and represent only a part of portal hypertension. Thus, the correlation may depend on the collateral circulation dynamics in the study population. In fact, previous reports on the association between esophageal varices and the liver stiffness or spleen stiffness are inconsistent. Some studies showed that the liver stiffness was positively correlated with the presence of esophageal varices , 10 and Previous studies with ARFI imaging , 8 showeOur study had limitations. First, we did not measure HVPG as the portal venous pressure; therefore, the correlation between the spleen stiffness and the portal venous pressure could not be evaluated. Another limitation was the relatively small sample size. Spleen stiffness, but not liver stiffness, was positively correlated with the presence of ascites as a representative marker of portal hypertension in patients with liver cirrhosis and the spleen stiffness did not correlate with the presence of esophageal varices in chronic hepatitis C patients. AFRI imaging showed the advantage of feasibility regardless of the presence of ascites, differing from the measurement by TE, and was applicable in patients who were unsuitable candidates for MRI, differing from the measurement by MRI elastography. However, our study is only preliminary due to the relatively small sample size, and a larger cohort study to verify our results is warranted in the future.


Clinical guidelines (CGs) are popular for healthcare decision making but their acceptability and use by healthcare providers is influenced by numerous factors. Some of these factors are professional-related, such as knowledge and perceptions of and attitudes toward CGs in general. The aim of our study was to evaluate attitudes and perceptions of Spanish physicians towards CGs.We coordinated six discussion groups with a total of 46 physicians. The participants were drawn from 12 medical specialties from both specialized and primary care. We recorded the sessions and transcribed the content verbatim. We analyzed the data using an approach based on the grounded theory.We identified two main constructs that defined the physicians' perceptions towards guidelines: knowledge and usefulness. “Knowledge” defined the theoretical meanings of guidelines, while “Usefulness” referred to the pragmatic approach to guidelines. These constructs were interrelated through a series of categories such as confidence, usability, accessibility, dissemination and formats.In our study, the constructs that impacted most on physician's attitudes to clinical guidelines were knowledge and usefulness. The tension between the theoretical and the pragmatic constructs determined the attitudes and how physicians use guidelines. Groups developing guidelines should ask relevant clinical questions and develop implementable and context specific recommendations. Developers should be explicit and consistent in the development and presentation of recommendations. Evidence-based medicine (EBM) has driven the use of tools for the critical synthesis of the literature, including systematic reviews and, more significantly, clinical guidelines (CGs). The former were recently defined as “statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options” Although concern has been raised over the trustworthiness of guidelines, several international initiatives have been put forward in order to develop credible guidelines. These endeavors, amongst other things, have targeted the vexing problem of guidelines and conflicts of interest, balancing the pros of having input from experts and assuring that conflicts of interest do not influence recommendations Health professionals' attitudes and expectations concerning EBM and CGs share some similarities. These include aspects such as a generally positive attitude toward bringing rigor to clinical practice, the need to improve their skills and the difficulties in the implementation of the evidence in real life In Spain, and despite the fact that CGs play a central role in the strategies to improve decision-making, several studies show that the implementation of CGs has certain drawbacks, such as the limited systematization and coordination of resources, the proliferation of guidelines that contrast with suboptimal updating, the redundancy in the subjects addressed, and biases in their methodology Another factor that may imply a barrier to the use of CGs is the existence of multiple systems for the formulation of recommendations, which sometimes have important limitations Qualitative research based on discussion groups. We reported the complete details of the study protocol elsewhere First, we organized six discussion groups in different geographical areas to reflect the regional differences in the organization of healthcare services in Spain. Enrolment of the 46 participating physicians from twelve medical specialties was carried out considering a purposive sample We designed a protocol to guide the moderation and the role of the observers, and to homogenize the process between groups. Similarly, we prepared a background document with general topics to be addressed in the group interviews, and with suggestions of both open and concrete questions that could be of assistance or guidance for moderators. To explore participants' perception regarding the different systems of classification and grading of the evidence, we prepared illustrative materials containing recommendations formulated with different rating systems.Discussion groups were moderated by members of the research team who had previous experience in that field, together with the collaboration of an observer, who collected field notes on anything that might be of interest for subsequent data analysis. No group interviews lasted more than ninety minutes. They were digitally audio-taped with the informants' consent and transcribed verbatim to obtain the final set of qualitative data for the analysis. The moderator initiated the discussion indirectly with an open-ended question (what comes to your mind when we speak about CGs?). During the session, the moderator assumed a minimally directive role, limiting intervention to prompting the group - if necessary - to address the topics in the script.Data were analysed in a first step from a theoretical approach based on the grounded theory in which categories of analysis were defined. This was later complemented with a discursive sociological approach that analysed discursive positions, narrative configurations and semantic spaces. All the analyses were triangulated between several members of the research team, and discussed with those in charge of the moderation and observation in each group utilization (implementation of the CPG in the setting of daily practice): confidence , access and dissemination , format (aspects related to the way information is presented), recommendations , and levels of scientific evidence .Physicians participating in the discussion groups showed that their perception of CGs was based on two main constructs related to their knowledge of CGs  and the possible usefulness of CGs (pragmatic characteristics). Both discursive constructs were involved in the following categories that shaped the participants' attitudes toward CGs and were also determinants of their The observed attitudes that define the knowledge construct that physicians have regarding CGs are based on a series of intellectual constructions on the characteristics of these documents, or the concepts supporting them. The main point in common when it comes to defining a CG, regardless of the methodological knowledge possessed by participants in the discussion groups in this respect, was that of the homogenizing function of CGs, which helps to standardize the practice, to organize assistance and, ultimately, to assist in clinical decision-making, assigning them an instrumental character .Participants easily identified the theoretical concepts that define CGs, showing a positive perception of medical professionals toward CGs as tools based either on scientific literature, or on a consensus that should homogenize the clinical practice . We obseAs to the attitudes towards CGs use, two differentiated behavioural patterns or demands were observed. First, there was the motivation of professionals to carry out an active search of documents that could facilitate their clinical practice. Second, professionals appeared to have a passive attitude, expecting the workplace organization  to facilitate access .CGs use in daily practice implies a process of implementation, involving dissemination and training in these documents. These two meanings constitute facilitating elements that take part in a positive feedback process, given that a correct dissemination and training contribute to a better knowledge and use of CGs .The perceived usefulness of CGs was identified as the main category filling the gap between theoretical knowledge and their use in the clinical practice. Physicians who participated in the discussion groups had a positive opinion about CGs as these tools can provide standards from which they can make the best possible decision when facing situations of uncertainty , althougAs for the CGs aim of reducing the variability in clinical practice, two opposing attitudes have been identified among participants in the discussion groups. On the one hand, CGs are perceived as useful tools for a correct approach of the most frequent conditions, and on the other hand, they are also perceived as assistance tools to address less common health issues of a lesser complexity .Availability of several formats of a CG is identified as another possible determinant of its use. Implementation and use of CGs could be facilitated by having a summarized version with concise information on the most important recommendations for clinical practice, submitting written recommendations in plain language with no ambiguities, and gaining access to an electronic format that allows for frequent updating .Another determinant in the use of CGs was confidence. Although the development and formulation process of recommendations is perceived as an important factor, participants in the discussion groups ascribed much more importance to those who develop and endorse the CGs. The fact that CGs developers can be expert methodologists or professionals not involved in clinical practice generates some rejection and limits their implementation. A factor that contributed most to the confidence perceived by health care professionals was authorship of recommendations, which could lead to a positive or negative attitude toward the use of a given CG. The involvement of the pharmaceutical industry in the development of CGs generates a certain attitude of suspicion, and even rejection to the recommendations included in CGs developed or financed by the same company .Certain aspects related to the usefulness of CGs create barriers to their use. One barrier is the inability of CGs to adapt or take into account the characteristics of the particular setting in which their recommendations are intended to be used, thus limiting its applicability. Their use is also limited by the availability of several CGs to address a single health problem; this makes it difficult to assimilate their contents, and recommendations may even diverge. Another point to consider is that updating of CGs may not keep up with scientific advances in certain pathologies, possibly triggering scepticism toward some of these documents .The collected data show that the levels of scientific evidence and the recommendations are a common element between the two main categories built upon discourse analysis (knowledge and use of CGs), being located in a macro-discourse level. They appear in the theoretical plane (as one of the basic components in the development of CGs), but also as a category that could guarantee credibility and confidence in CGs, thus facilitating their use, dissemination, and access.CGs methodological sections, with information such as tables synthesizing the evidence that back up the recommendations, were highly regarded by participants, since they are perceived as indicators of strictness, responsibility and transparency. However, although the inclusion of these sections in CGs adds value, it does not necessarily mean that users know how to handle them, since some knowledge of research methodology is needed to this end .Although the moderators of the groups tried to explore participants' perception of the different ways in which levels of evidence and the strength of the recommendations were graded, participants showed little interest in the grading models used. In general, participants showed a preference for systems based on numbers and letters to classify the evidence and grade the strength of the recommendations . The lacOur study identified two main constructs explaining how physicians perceive CGs, and how this perception impacts on the attitude towards them. On one hand, there is a conception at the level of knowledge of CGs  and, on the other hand, there are a series of categories related to their usefulness (from a pragmatic construction). The categories identified in the texts from the discussion groups shape aspects that enable us to relate these two main constructs, acting both as facilitators in the implementation of this conceptual perception of CGs, and as barriers to their use.Overall, health care professionals show a positive attitude toward CGs, regarding them as useful tools to standardize clinical practice and shared decision-making. However, a number of factors appear to hinder their practical use. These factors are related to aspects such as a limited knowledge and limited access to CGs, lack of confidence in developers, lack of manageable formats in daily clinical practice, and the absence of standardized classification systems of the levels of evidence and recommendations.Some barriers to the use of CGs have also been identified around these two constructs. The main sceptical attitudes toward CGs are related, on one hand, to the often difficult applicability of the scientific literature that supports recommendations at the individual level Our study suggests that an important barrier to the use of CGs, and a factor of physicians' perception of their usefulness, is the disagreement between the theoretical content of CGs and the daily practice. The role played by health professionals as primary actors in decision-making in clinical practice can differ from the objectives of CGs As in other studies Some of the barriers to the use of CGs have been associated with practical aspects in our study, as other authors have also pointed out Some participants in our study expressed the need to disseminate CGs better before their implementation Dissemination, form of access to CGs, and CGs format are the main determinants of their knowledge and use. Overall, the literature also identifies format as a facilitator for their use Contrary to our expectations, the participants in the discussion groups did not devote much time discussing grading systems. This is due to the natural complexity of qualitative designs and specifically in group discussions. A researcher who moderates group discussions has less control over the data produced than in in-depth interviews or quantitative studies. Participants expressed that the lack of standardized classification systems could be responsible for considerable confusion among users and a potential barrier to the use of CGs. This topic clearly deserves further research. Other authors highlight the importance of standardizing these systems to find a balance between rigour and simplicity Our study highlights the involvement that CGs developer groups should have when developing CGs aimed at answering specific and relevant questions. They should count on all the actors implicated, and they should be explicit, consistent and strict in the process of development. Finally, it is important that CGs are accompanied by working tools that strengthen their utility, trying to facilitate their dissemination and applicability, and taking into account the need to adapt CG formats to the specific characteristics of the different user profiles.