Search

This article is an executive summary of a report from the Centers for Disease Control and Prevention Ventilator-Associated Pneumonia Surveillance Definition Working Group, entitled "Developing a New, National Approach to Surveillance for Ventilator-Associatied Events," published in Critical Care Medicine, by Magill SS, Klompas M, Balk R, Burns SM, Deutschman CS, et al. 2013;41(11):2467-2475. The full report provides a comprehensive description of the Working Group's process and outcome.

Introduction: Professional societies, like many other organizations around the world, have recognized the need to use more rigorous processes to ensure that health care recommendations are informed by the best available research evidence. This is the seventh of a series of 14 articles that were prepared to advise guideline developers in respiratory and other diseases on approaches for guideline development. This article focuses on synthesizing, rating, and presenting evidence in guidelines., Methods: In this review we addressed the following questions. (1) What evidence should guideline panels use to inform their recommendations? (2) How should they rate the quality of the evidence they use? (3) How should they grade evidence regarding diagnostic tests? (4) What should they do when quality of evidence differs across outcomes? (5) How should they present the evidence in a guideline? We did not conduct systematic reviews ourselves. We relied on prior evaluations of electronic databases and systematic reviews suggesting that the Grades of Recommendation, Assessment, Development and Evaluation Working Group (GRADE) approach includes the desired features of a system for grading quality of evidence, including provision of models for presenting evidence for guideline panels, and for the consumers of practice guidelines. This article describes the GRADE approach to grading the quality of evidence and presenting evidence. Available evidence, the practice of leading guideline developers, and workshop discussions provide the basis for our conclusions., Results and Discussion: GRADE rates the quality of evidence for each outcome across studies rather than for each study. In the GRADE approach randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down or up. Five factors may lead to rating down the quality of evidence: study limitations or risk of bias, inconsistency of results, indirectness of evidence, imprecision, and publication bias. Three factors may lead to rating up the quality of evidence from observational studies: large magnitude of effect, dose-response gradient, and situations in which all plausible confounders would decrease an apparent treatment effect, or would create a spurious effect when results suggest no effect. GRADE suggests use of evidence profiles that provide a comprehensive way to display the key evidence relevant to a clinical question. Guideline developers who follow this structure will find the transparency of their recommendations markedly enhanced.

Issues of financial and intellectual conflict of interest in clinical practice guidelines have raised increasing concern. Professional organizations have responded by more rigorous regulation of conflict of interest. Nevertheless, tension remains between the competing goals of optimizing guideline quality by using the experience and insight of experts and ensuring that financial and intellectual conflicts of interest do not influence recommendations. The executive committee of the American College of Chest Physicians' Antithrombotic Guidelines has developed a strategy comprising 3 innovative aspects to address this tension: First, place equal emphasis on intellectual and financial conflicts and provide explicit criteria for both; second, a methodologist without important conflicts of interest should have primary responsibility for each chapter; and third, experts with important financial or intellectual conflicts of interest can collect and interpret evidence, but only panel members without important conflicts can be involved in developing the recommendation for a specific question. These strategies may help to achieve the benefits of expert input without conflicts of interest influencing recommendations.

This chapter about antithrombotic therapy for coronary artery disease is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicans Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggestions are weaker as there is uncertainty regarding the benefits, risks and costs such that individual patients' values may lead to different choices (for a full understanding of the grading see the "Grades of Recommendation for Antithrombotic Agents" chapter by Guyatt et al, CHEST 2008; 133[suppl]:123S-131S). Among the key recommendations are the following: for all patients presenting with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS), without a clear allergy to aspirin, we recommend immediate aspirin (162 to 325 mg po) and then daily oral aspirin (75 to 100 mg) [Grade 1A]. For NSTE ACS patients who are at at least moderate risk for an ischemic event and who will undergo an early invasive management strategy, we recommend "upstream" treatment either with clopidogrel (300 mg po bolus, followed by 75 mg/d) or a small-molecule IV glycoprotein (GP) IIb/IIIa inhibitor (eptifibatide or tirofiban) [Grade 1A]. For NSTE ACS patients who are at least moderate risk for an ischemic event and for whom an early conservative or a delayed invasive strategy of management is to be used, we recommend "upstream" treatment with clopidogrel (300 mg oral bolus, followed by 75 mg/d) [Grade 1A]. For NSTE ACS patients who undergo PCI, we recommend treatment with both clopidogrel and an IV GP IIb/IIIa inhibitor (Grade 1A). We recommend a loading dose of 600 mg of clopidogrel given at least 2 h prior to planned PCI followed by 75 mg/d (Grade 1B). For all patients presenting with NSTE ACS, we recommend anticoagulation with UFH or LMWH or bivalirudin or fondaparinux over no anticoagulation (Grade 1A). For NSTE ACS patients who will undergo an early invasive strategy of management, we recommend UFH (with a GP IIb/IIIa inhibitor) over either LMWH or fondaparinux (Grade 1B). For NSTE ACS patients in whom an early conservative or a delayed invasive strategy of management is to be used, we recommend fondaparinux over enoxaparin (Grade 1A) and LMWH over UFH (Grade 1B). We recommend continuing LMWH during PCI treatment of patients with NSTE ACS when it has been started as the "upstream" anticoagulant (Grade 1B). In low- to moderate-risk patients with NSTE ACS undergoing PCI, we recommend either bivalirudin with provisional ("bail-out") GP IIb/IIIa inhibitors or UFH plus a GP IIb/IIIa inhibitor over alternative antithrombotic regimens (Grade 1B).

Evidence-based clinical practice guidelines (EBGs) can provide an invaluable distillation of knowledge regarding best practices based on the available evidence. EBGs, providing accurate and useful guidance to best clinical practices, require a rigorous development process. The American College of Chest Physicians (ACCP) has developed a process that embodies transparency, thoroughness, and timeliness, and effective conflict-of-interest management, and it continues to evolve. This process employs a quantitative and rigorous grading of the strength of recommendations and of the quality of evidence that incorporates sensitivity to health-care resource utilization and patient values and preferences. A review of this process is provided to inform the ACCP membership and those wishing to embark on EBG development.

Most panels that develop clinical practice guidelines are poorly equipped to address resource allocation or cost issues associated with management options. This risks neglect, arbitrariness, lack of transparency, and methodological flaws in consideration of resource allocation. We provide recommendations for guideline panels to promote greater transparency and rigor. We suggest focusing on resource allocation issues for only a limited number of recommendations and provide criteria for selecting those in which economic considerations are likely to influence the direction or strength of the recommendation. Panels should involve a health economist to assist with the systematic review and critical interpretation of relevant economic analyses. They should carefully define the intended audience and may consider issuing alternative recommendations when available resources vary widely across target clinical settings. Targeting a limited number of recommendations for the consideration of resource allocation issues, and ensuring methodologically high-quality review, will best serve guideline panels, and the health-care providers and patients they hope to assist.

While grading the strength of recommendations and the quality of underlying evidence enhances the usefulness of clinical guidelines, the profusion of guideline grading systems undermines the value of the grading exercise. An American College of Chest Physicians (ACCP) task force formulated the criteria for a grading system to be utilized in all ACCP guidelines that included simplicity and transparency, explicitness of methodology, and consistency with current methodological approaches to the grading process. The working group examined currently available systems, and ultimately modified an approach formulated by the international GRADE group. The grading scheme classifies recommendations as strong (grade 1) or weak (grade 2), according to the balance among benefits, risks, burdens, and possibly cost, and the degree of confidence in estimates of benefits, risks, and burdens. The system classifies quality of evidence as high (grade A), moderate (grade B), or low (grade C) according to factors that include the study design, the consistency of the results, and the directness of the evidence. For all future ACCP guidelines, The College has adopted a simple, transparent approach to grading recommendations that is consistent with current developments in the field. The trend toward uniformity of approaches to grading will enhance the usefulness of practice guidelines for clinicians.

Whole-blood viscosity appears to be an independent predictor of stroke, carotid intima-media thickening, and carotid atherosclerosis. The purpose of this study was to examine for relationships between whole-blood viscosity and blood lipids in young healthy subjects over a range of shear rates. Twenty-seven healthy men and women aged 10 to 25 years having a range of low-density lipoprotein (LDL) cholesterol values 88 to 258 mg/dL and body mass index z scores -1.18 to 2.64 SDs were studied. Whole-blood viscosity at shear rates from 1 to 1000 per second was measured using an automated capillary viscometer. Blood lipids were measured using standard techniques. Triglyceride-rich lipoproteins were isolated by ultracentrifugation at density of <1.020 g/mL, and a high ratio of cholesterol to triglyceride was used as an indicator of lipoprotein remnants. Whole-blood viscosity at shear rates of 100 to 1000 per second showed significant negative correlations with apolipoprotein A-1, but not with high-density lipoprotein cholesterol. Whole-blood viscosity at a shear rate of 1000 per second correlated with LDL cholesterol and inversely with LDL size. On stepwise multivariate analysis, apolipoprotein A-1 accounted for 14.7% of the variation in whole-blood viscosity at a shear rate of 150 per second. This study points to the importance of high-density lipoprotein particle number on whole-blood viscosity at physiological shear rates. The physiological significance of the relationships between whole-blood viscosity and LDL cholesterol and LDL particle size at a very high shear rate remains to be determined.

Background: The influence of dietary carbohydrate glycemic index on blood lipids has not been well studied. Assessment of glycemic load is not usually included in a standard dietary analysis., Objective: The purpose of the present study was to examine relations between diet and blood lipids in youth with a broad range of cholesterol values and carbohydrate, fat, and protein intakes., Design: Relations between blood lipids and dietary constituents were examined in 32 healthy males and females aged 11-25 y. Subjects exhibited a range of LDL-cholesterol values (1.71-6.67 mmol/L) and body mass index z scores (-1.18 to 2.64). Dietary constituents were assessed from 3-d food diaries., Results: The only significant correlations evident were negative correlations between HDL cholesterol and glycemic load (in relation to white bread), percentage carbohydrate, total dietary sugar, total carbohydrate, and fructose. On stepwise multiple regression analysis, glycemic load accounted for 21.1% of the variation in HDL cholesterol., Conclusions: Glycemic load appears to be an important independent predictor of HDL cholesterol in youth. This relation is of concern and suggests that dietary restrictions without attention to a possible resulting increase in glycemic load may result in an unfavorable influence on blood lipids.

This chapter about prevention of coronary artery bypass occlusion is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients undergoing coronary artery bypass grafting (CABG), we recommend aspirin, 75 to 162 mg/d, starting 6 h after operation over preoperative aspirin (Grade 1A). In patients in whom postoperative bleeding prevents the administration of aspirin at 6 h after CABG, we recommend starting aspirin as soon as possible thereafter (Grade 1C). For patients undergoing CABG, we recommend against addition of dipyridamole to aspirin therapy (Grade 1A). For patients with coronary artery disease undergoing CABG who are allergic to aspirin, we recommend clopidogrel, 300 mg, as a loading dose 6 h after operation followed by 75 mg/d p.o. (Grade 1C+). In patients who undergo CABG for non-ST-segment elevation acute coronary syndrome (ACS), we recommend clopidogrel, 75 mg/d for 9 to 12 months following the procedure in addition to treatment with aspirin (Grade 1A). For patients who have received clopidogrel for ACS and are scheduled for CABG, we recommend discontinuing clopidogrel for 5 days prior to the scheduled surgery (Grade 2A). For patients undergoing CABG who have no other indication for vitamin K antagonists (VKAs), we suggest clinicians to not administer VKAs (Grade 2B). For patients undergoing CABG in whom oral anticoagulants are indicated, such as those with heart valve replacement, we suggest clinicians administer VKA in addition to aspirin (Grade 2C). For all patients with coronary artery disease who undergo internal mammary artery (IMA) bypass grafting, we recommend aspirin, 75 to 162 mg/d, indefinitely (Grade 1A). For all patients undergoing IMA bypass grafting without other indication for VKA, we suggest clinicians not use VKA (Grade 2C).

Pulmonary arterial hypertension (PAH) occurs as an idiopathic process or as a component of a variety of disease processes, including chronic thromboembolic disease, connective tissue diseases, congenital heart disease, and exposure to exogenous factors including appetite suppressants or infectious agents such as HIV. This article reviews evidence for screening in susceptible patient groups and the approach to diagnosing PAH when it is suspected, and provides specific recommendations for applying this evidence to clinical practice.