Methodology for the development of antithrombotic therapy and prevention of thrombosis guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
BACKGROUND
To develop the Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: ACCP Evidence-Based Clinical Practice Guidelines (AT9), the American College of Chest Physicians (ACCP) assembled a panel of clinical experts, information scientists, decision scientists, and systematic review and guideline methodologists.


METHODS
Clinical areas were designated as articles, and a methodologist without important intellectual or financial conflicts of interest led a panel for each article. Only panel members without significant conflicts of interest participated in making recommendations. Panelists specified the population, intervention and alternative, and outcomes for each clinical question and defined criteria for eligible studies. Panelists and an independent evidence-based practice center executed systematic searches for relevant studies and evaluated the evidence, and where resources and evidence permitted, they created standardized tables that present the quality of the evidence and key results in a transparent fashion.


RESULTS
One or more recommendations relate to each specific clinical question, and each recommendation is clearly linked to the underlying body of evidence. Judgments regarding the quality of evidence and strength of recommendations were based on approaches developed by the Grades of Recommendations, Assessment, Development, and Evaluation Working Group. Panel members constructed scenarios describing relevant health states and rated the disutility associated with these states based on an additional systematic review of evidence regarding patient values and preferences for antithrombotic therapy. These ratings guided value and preference decisions underlying the recommendations. Each topic panel identified questions in which resource allocation issues were particularly important and, for these issues, experts in economic analysis provided additional searches and guidance.


CONCLUSIONS
AT9 methodology reflects the current science of evidence-based clinical practice guideline development, with reliance on high-quality systematic reviews, a standardized process for quality assessment of individual studies and the body of evidence, an explicit process for translating the evidence into recommendations, disclosure of financial as well as intellectual conflicts of interest followed by management of disclosed conflicts, and extensive peer review.
Department of Clinical Epidemiology and Biostatistics, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada; Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada. Electronic address: guyatt@mcmaster.ca.
Gordon H
GH
Guyatt
Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR.
Susan L
SL
Norris
Department of Clinical Epidemiology and Biostatistics, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada; Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
Sam
S
Schulman
Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
Jack
J
Hirsh
Division of General Internal Medicine and Center for Clinical Effectiveness, University of Cincinnati, Cincinnati, OH.
Mark H
MH
Eckman
Department of Clinical Epidemiology and Biostatistics, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada; Departments of Medicine and Family Medicine, State University of New York, Buffalo, NY.
Elie A
EA
Akl
Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
Mark
M
Crowther
Department of Medicine Gjøvik-Innlandet Hospital Trust and Norwegian Knowledge Centre for the Health Services, Oslo, Norway.
Per Olav
PO
Vandvik
Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
John W
JW
Eikelboom
Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR.
Marian S
MS
McDonagh
Evidence-Based Clinical Practice Guidelines and Clinical Standards, American College of Chest Physicians, Northbrook, IL.
Sandra Zelman
SZ
Lewis
Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI.
David D
DD
Gutterman
Department of Clinical Epidemiology and Biostatistics, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada; Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
Deborah J
DJ
Cook
Department of Clinical Epidemiology and Biostatistics, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada; Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada.
Holger J
HJ
Schünemann
D019317:Evidence-Based Medicine; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D017410:Practice Guidelines as Topic; D012955:Societies, Medical; D013927:Thrombosis / Q000188:drug therapy* / Q000517:prevention & control*; D014481:United States
D005343:Fibrinolytic Agents