Understanding Evidence-Based Medicine in Clinical Practice

1. Evidence-Based Medicine in Clinical Practice. Dr. Harry Gee Dr. Chisale Mhango

2. "Every intervention is a two-edged sword." Iain Chalmers

3. Old paradigm Unsystematic clinical experience Pathophysiology Content expertise & authoritarianism New paradigm Systematic clinical experience Pathophysiology necessary but not sufficient Rules of evidence Practice Pradigms

4. Pre-Requisites Questioning The Knowledge Gap Honesty Humility Discerning What is merely custom and practice? Desire for Improvement

5. Our Aims • Understand EBM • What is it? • Why do we need it? • What are the benefits? • Who benefits?

6. Our Objectives The key steps: • Formulate a clinical question • Search the literature • Efficiently • Confidently • Appraise the evidence • Apply the evidence

7. What is EBM?

8. Good Clinical Practice • Knowledge from best external evidence based on clinical research • Judgement from experience. • Understanding of patient's beliefs & preferences. Sackett 1996

9. Who Benefits?

10. Evidence Based Medicine Conscientious, explicit and judicious use of current best evidence in making decisions about the care of an individual patient Sackett. BMJ 1996;312:311-2

11. EBM for the Clinician • Knowledge & Skills • Proficiency • Application • PRACTICE • Confidence

12. The 5 Steps Towards Evidence Based Practice 1. Ask the right clinical question: Formulate a searchable question 2. Collect the most relevant publications: Efficient Literature Searching Select the appropriate & relevant studies 3. Critically appraise and synthesize the evidence. 4. Integrate best evidence with personal clinical expertise, patient preferences and values: Applying the result to your clinical practice and patient. 5. Evaluate the practice decision or change: Evaluating the outcomes of the applied evidence in your practice or patient.

13. Asking the Right Questions

14. Clinical Process and knowledge requirements Research evidence sought from literature searches Etiology knowledge about causation Etiognostic Research Patient presentation knowledge about diagnosis • Testing • History • Examination • Investigations Diagnostic Research Diagnosis knowledge about prognosis Prognostic Research • Therapy • Changes prognosis Therapy Research knowledge about therapeutic effectiveness Clinical outcome

15. The Question - Why is it so Important? • A good answerable question will help us focus on evidence that is relevant to a patient’s clinical needs, (or your own knowledge needs). • They can suggest high yield search strategies • They can suggest the forms that useful answers might take (i.e. what is best research design to answer our question)

16. Formulating Clinical Questions • There is no right or wrong way to turn a scenario/knowledge need into a question. • Just make sure it is concise, clinical and uses appropriate language (avoid colloquialism, in favour of technical language). • Ask one question at a time.

17. PICO(D) Population Intervention Comparison Outcome (Design)

18. Select best evidence Question Relevant Focussed Appropriate Study Type Up to Date

19. Research Study Design

20. Diagnostic tests Prognosis Therapy Patients’ Preferences Cross sectional study Cohort study RCT Qualitative research Research Design BMJ 1997;315:1636

21. What resources could be searched?

22. Why Should We Be Critical in Our Reading of the Literature?

23. Quality of the Medical Literature Journal High Quality Articles N Eng J Med 17% Ann Intern Med 13% JAMA 12% BMJ 9% Lancet 8%

24. What do we mean byResearch Quality?

25. Quality of a Study The confidence that the study design, conduct and analysis has minimized biases in addressing the research question The better the quality, the higher is the likelihood that the results produced in the study are credible

26. Quality of a Study Validity • The degree to which the results of an observation are correct for the patients being studied. Bias • A process that tends to produce results that depart systematically from the true values existing in the study population. Fletcher et al, 1988; Murphy, 1976

27. Bias • Conscious • Unconscious • Conflict of Interest

28. The Hawthorne Effect What is it?

29. Hawthorne Effect • Outcomes changed • By virtue of doing the study • Irrespective of the intervention

30. Hierachy of Evidence • Experimental studies • Randomized controlled trials • Controlled Observational studies • Case-control studies • Uncontrolled Observational studies • Case series • Case reports Sacks et al. Am J Med 1982;72:233-240; Cook et al. Chest 1992;102:305s-311s; Guyatt et al. JAMA 1993;270:2598-2601

31. EBM Basic Skills • Formulate structured clinical question • PICO(D) • Search for evidence • Systematic • Select best evidence • Critically appraise • GATE Frame • RAMMbo • CASP • CAT maker

32. AT-A-GLANCE • Acronym • Title • Aim • Groups • Limbs – Intervention v Comparator • Absolute Risk Reduction • Number Needed to Treat (NNT) • Clinical Conclusion • Education for patients/carers

33. AT-A-GLANCE • Acronym:is there a study name? as a mnemonic • Title: Full title, authors, institute, journal, full reference • Aim:specific aim of the study and why, what outcomes were used? • Groups: who were the research subjects, inclusion criteria, exclusion criteria, who excluded by chance or bias • Limbs –Intervention v Comparator, ? Versus placebo, ? Blinded, how randomised, • Absolute Risk Reduction: What the main results?, what the main results on the outcomes studied, other main results, ? Side-effects, other harm events • Number Needed to Treat (NNT): How many people do you need to treat to have one beneficial effect? Eg how many people to save a life? How many treated to have side-effects? • Clinical Conclusion: What are the main clinical conclusions for you and the team? Can the results be implemented locally? ? Change in guideline needed? ? Clinical audit needed? • Education for patients/carers: How can you explain the results to a patient/guardian prior to consent and explanation? State what you will actually say eg “Research has shown that………what do you think?”

34. Guidelines

35. Levels of evidence Level Type of evidence I Evidence obtained from at least one randomised controlled trial or from meta-analysis of randomised controlled trials II Evidence obtained from at least one well-designed controlled study without randomisation III Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case control studies IV Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities

36. Grading of recommendations Grade Recommendation A (Evidence level I) Requires at least one randomised controlled trial as part of the body of literature of overall good quality and consistency addressing the specific recommendation B (Evidence levels II, III) Requires availability of well-conducted clinical studies but not randomised clinical trials on the topic of recommendation C (Evidence level IV) Requires evidence from expert committee reports or opinions and/or clinical experience of respected authorities. Indicates absence of directly applicable studies of good quality

37. To Summarise

38. Clinical problem Expertise, Experience & Pathophysiology Summary

39. Clinical problem Expertise, Experience & Pathophysiology Summary Develop answerable questions

40. Clinical problem Expertise, Experience & Pathophysiology Search and obtain relevant articles Summary Develop answerable questions

41. Clinical problem Expertise, Experience & Pathophysiology Search and obtain relevant articles Critical appraisal of evidence Summary Develop answerable questions

42. Clinical problem Expertise, Experience & Pathophysiology Search and obtain relevant articles Critical appraisal of evidence Summary Develop answerable questions Decision making about diagnosis & treatment

43. Clinical problem Expertise, Experience & Pathophysiology Search and obtain relevant articles Critical appraisal of evidence Summary Develop answerable questions Decision making about diagnosis & treatment

44. Performance Competence Knowledge Skills Proficiency Application PRACTICE Confidence

45. Are We Together ???