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GRADE Introduction

Holger Schünemann, MD, PhD Professor Utrecht, NL September 18 - 19, 2008. GRADE Introduction. Disclosure.

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GRADE Introduction

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  1. Holger Schünemann, MD, PhD Professor Utrecht, NL September 18 - 19, 2008 GRADE Introduction

  2. Disclosure In the past three years, Dr. Schünemann received no personal payments for service from the pharmaceutical industry. His research group received research grants and - until April 2008 - fees and/or honoraria that were deposited into research accounts from Chiesi Foundation and Lily, as lecture fees related to research methodology. He is documents editor for the American Thoracic Society. Institutions or organizations that he is affiliated with likely receive funding from for-profit sponsors that are supporting infrastructure and research that may serve his work.

  3. Content • Background and rationale for revisiting guideline methodology • GRADE approach • Quality of evidence • Strength of recommendations

  4. Content • Background and rationale for revisiting guideline methodology • GRADE approach • Quality of evidence • Strength of recommendations

  5. Confidence in evidence • There always is evidence • “When there is a question there is evidence” • Evidence alone is never sufficient to make a clinical decision • Better research  greater confidence in the evidence and decisions

  6. Hierarchy of evidence • STUDY DESIGN • Randomized Controlled Trials • Cohort Studies and Case Control Studies • Case Reports and Case Series, Non-systematic observations BIAS Expert Opinion Expert Opinion Expert Opinion

  7. Can you explain the following? • Concealment of randomization • Blinding (who is blinded in a double blinded trial?) • Intention to treat analysis and its correct application • Why trials stopped early for benefit overestimate treatment effects? • P-values and confidence intervals

  8. Hierarchy of evidence • STUDY DESIGN • Randomized Controlled Trials • Cohort Studies and Case Control Studies • Case Reports and Case Series, Non-systematic observations BIAS Expert Opinion

  9. Reasons for grading evidence? • People draw conclusions about the • quality of evidence and strength of recommendations • Systematic and explicit approaches can help • protect against errors, resolve disagreements • communicate information and fulfil needs • Change practitioner behavior • However, wide variation in approaches GRADE working group. BMJ. 2004 & 2008

  10. Evidence Recommendation B Class I A 1 IV C Organization AHA ACCP SIGN Which grading system? Recommendation for use of oral anticoagulation in patients with atrial fibrillation and rheumatic mitral valve disease

  11. A COPD guidelines

  12. Another COPD guidelines

  13. And another COPD guideline

  14. What to do?

  15. Content • Background and rationale for revisiting guideline methodology • GRADE approach • Quality of evidence • Strength of recommendations

  16. Limitations of existing systems • confuse quality of evidence with strength of recommendations • lack well-articulated conceptual framework • criteria not comprehensive or transparent • GRADE unique • breadth, intensity of development process • wide endorsement and use • conceptual framework • comprehensive, transparent criteria • Focus on all important outcomes related to a specific question and overall quality

  17. Grades of Recommendation Assessment, Development and Evaluation GRADE Working Group CMAJ 2003, BMJ 2004, BMC 2004, BMC 2005, AJRCCM 2006, Chest 2006, BMJ 2008

  18. David Atkins, chief medical officera Dana Best, assistant professorb Martin Eccles, professord Francoise Cluzeau, lecturerx Yngve Falck-Ytter, associate directore Signe Flottorp, researcherf Gordon H Guyatt, professorg Robin T Harbour, quality and information director h Margaret C Haugh, methodologisti David Henry, professorj Suzanne Hill, senior lecturerj Roman Jaeschke, clinical professork Regina Kunx, Associate Professor Gillian Leng, guidelines programme directorl Alessandro Liberati, professorm Nicola Magrini, directorn James Mason, professord Philippa Middleton, honorary research fellowo Jacek Mrukowicz, executive directorp Dianne O’Connell, senior epidemiologistq Andrew D Oxman, directorf Bob Phillips, associate fellowr Holger J Schünemann, professorg,s Tessa Tan-Torres Edejer, medical officert David Tovey, Editory Jane Thomas, Lecturer, UK Helena Varonen, associate editoru Gunn E Vist, researcherf John W Williams Jr, professorv Stephanie Zaza, project directorw a) Agency for Healthcare Research and Quality,USA b) Children's National Medical Center, USA c) Centers for Disease Control and Prevention, USA d) University of Newcastle upon Tyne, UK e) German Cochrane Centre, Germany f) Norwegian Centre for Health Services, Norway g) McMaster University, Canada h) Scottish Intercollegiate Guidelines Network, UK i) Fédération Nationale des Centres de Lutte Contre le Cancer, France j) University of Newcastle, Australia k) McMaster University, Canada l) National Institute for Clinical Excellence, UK m) Università di Modena e Reggio Emilia, Italy n) Centro per la Valutazione della Efficacia della Assistenza Sanitaria, Italy o) Australasian Cochrane Centre, Australia p) Polish Institute for Evidence Based Medicine, Poland q) The Cancer Council, Australia r) Centre for Evidence-based Medicine, UK s) National Cancer Institute, Italy t) World Health Organisation, Switzerland u) Finnish Medical Society Duodecim, Finland v) Duke University Medical Center, USA w) Centers for Disease Control and Prevention, USA x) University of London, UK Y) BMJ Clinical Evidence, UK GRADE Working Group

  19. GRADE Uptake • World Health Organization • Allergic Rhinitis in Asthma Guidelines (ARIA) • American Thoracic Society • British Medical Journal • Infectious Disease Society of America • American College of Chest Physicians • UpToDate • American College of Physicians • Cochrane Collaboration • National Institute Clinical Excellence (NICE) • Infectious Disease Society of America • European Society of Thoracic Surgeons • Clinical Evidence • Agency for Health Care Research and Quality (AHRQ) • Over 20 major organizations

  20. The GRADE approach Clear separation of 2 issues: 1) 4 categories of quality of evidence: very low, low, moderate, or high quality? • methodological quality of evidence • likelihood of bias • by outcome 2) Recommendation: 2 grades - weak or strong (for or against)? • Quality of evidence only one factor *www.GradeWorkingGroup.org

  21. GRADE Quality of Evidence “Extent to which confidence in estimate of effect adequate to support decision” • high: considerable confidence in estimate of effect. • moderate: further research likely to have impact on confidence in estimate, may change estimate. • low: further research is very likely to impact on confidence, likely to change the estimate. • very low: any estimate of effect is very uncertain

  22. Determinants of quality • RCTs start high • observational studies start low • 5 factors lower the quality of evidence • detailed design and execution • inconsistency • indirectness • reporting bias • Imprecision • 3 factors can increase the quality of evidence

  23. Quality assessment criteria

  24. Example: Design and Execution • limitations • Randomization • lack of concealment • intention to treat principle violated • inadequate blinding • loss to follow-up • early stopping for benefit

  25. Design and Execution • From Cates , CDSR 2008 CDSR 2008

  26. Design and Execution Overall judgment required

  27. What can raise quality?3 Factors • large magnitude can upgrade one level • very large two levels • common criteria • everyone used to do badly • almost everyone does well • Epinephrin in allergic shock • dose response relation (higher INR – increased bleeding) • Residual confounding unlikely to be responsible for observed effect

  28. Guideline development process GRADE

  29. Guideline development process Summary of Findings GRADE

  30. GRADE Profiles

  31. Summary of Findings Tables

  32. Studies S1 S2 S3 S4 S5 Health Care Question (PICO) Systematic reviews Outcomes OC1 OC2 OC4 OC3 Important outcomes Critical outcomes OC1 OC2 OC3 OC4 Rate the quality of evidence for each outcome, across studies RCTs start high, observational studies start low (-) Study limitations Imprecision Inconsistency of results Indirectness of evidence Publication bias likely Final rating of quality for each outcome: high, moderate, low, or very low (+) Large magnitude of effect Dose response Plausible confounders would ↓ effect when an effect is present or ↑ effect if effect is absent Reevaluate estimate of effect for each outcome Rate overall quality of evidence (GRADE) (lowest quality among critical outcomes) Decide on the direction (for/against) and grade strength of the recommendation (strong/weak*) considering: Quality of the evidence Balance benefits/harms Values and preferences Decide if any revision of direction or strength is necessary considering: Resource use *also labeled “conditional” Norris 9/11/08

  33. The clinical scenario A 68 year old male long-term patient of yours. He suffers from COPD but is unable to stop smoking after over 30 years of tobacco use. He has been taking beta-carotene supplements for several months because someone in the “healthy food” store recommended it to prevent cancer. He wants to know whether this will prevent him from getting cancer and whether he should use beta-carotene.

  34. Strength of recommendation • “The strength of a recommendation reflects the extent to which we can, across the range of patients for whom the recommendations are intended, be confident that desirable effects of a management strategy outweigh undesirable effects.”

  35. Desirable and undesirable effects • Desirable effects • Mortality • improvement in quality of life, fewer hospitalizations/infections • reduction in the burden of treatment • reduced resource expenditure • Undesirable effects • deleterious impact on morbidity, mortality or quality of life, increased resource expenditure

  36. Determinants of the strength of recommendation

  37. Developing recommendations

  38. Implications of a strong recommendation • Patients: Most people in this situation would want the recommended course of action and only a small proportion would not • Clinicians: Most patients should receive the recommended course of action • Policy makers: The recommendation can be adapted as a policy in most situations

  39. Implications of a weak recommendation • Patients: The majority of people in this situation would want the recommended course of action, but many would not • Clinicians: Be prepared to help patients to make a decision that is consistent with their own values/decision aids and shared decision making • Policy makers: There is a need for substantial debate and involvement of stakeholders

  40. A COPD guidelines

  41. Another COPD guidelines

  42. And another COPD guideline

  43. The clinical question Population: In smokers with COPD Intervention: does beta-carotene suppl Comparison: compared to no suppl. Outcomes: reduce the risk of COPD symptoms, lung cancer and death and improve PFTs?

  44. Two trials 1) The Alpha-Tocopherol Beta-Carotene (ATBC) trial randomly assigned 29,133 people to receive beta carotene, tocopherol, both, or placebo. Study participants averaged 57.2 years of age, 20.4 cigarettes per day, and 35.9 years of smoking. They were followed up for 5 to 8 years. RR for lung cancer = 1.16 (95% CI 1.02-1.33) Albanes et al, JNCI, 1996

  45. Two trials 2) The Beta-Carotene and Retinol Efficacy Trial (CARET) evaluated high-risk current and former smokers with a 20–pack-year history of smoking (n = 14,254), ~ 60 years old. The participants were randomly assigned to receive either a combination of beta carotene and vitamin A or placebo. Mean length of follow up: 4 years. RR for lung cancer = 1.28 (95% CI 1.04-1.57)

  46. Determinants of the strength of recommendation

  47. Determinants of the strength of recommendation

  48. Determinants of the strength of recommendation Table. Decisions about the strength of a recommendation Frequent “yes” answers will increase the likelihood of a weak recommendation

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