Evidence-Based Medicine (6th ed.)

Buy the book
EBM Toolbox

Description

A unique and valuable resource for busy clinicians at any stage of their career, Evidence-Based Medicine: How to Practice and Teach EBM, 6th Edition, is ideal for those who want to learn how to effectively practice and teach evidence-based medicine (EBM). This classic introduction to EBM has been thoroughly updated from cover to cover, while retaining its short, practical format that emphasizes the direct clinical application of EBM and provides the tactics to practice and teach EBM in real time and in various settings. Written by internationally renowned practising clinicians, methodologists, and teachers, this bestselling text offers easy-to-read, accessible coverage of all the basics of EBM for time-constrained undergraduate and postgraduate medical learners, instructors, and practitioners in all clinical areas of health care.

The online toolkit includes Critical appraisal worksheets, Educational prescription, Pocket Cards, EBM calculators, Educational Prescriptions, Clinical Questions log, Self evaluations.

Introduction to Evidence-Based Medicine: What is EBM?

Evidence-based medicine (EBM) requires the integration of the best research evidence with our clinical expertise and our patient’s unique values and circumstances.

  • By best research evidence, we mean clinically relevant research, sometimes from the basic sciences of medicine, but especially from patient-centered clinical research into the accuracy and precision of diagnostic tests (including the clinical examination), the power of prognostic markers, and the efficacy and safety of therapeutic, rehabilitative, and preventive strategies.
  • By clinical expertise, we mean the ability to use our clinical skills and past experience to rapidly identify each patient’s unique health state and diagnosis, their individual risks and benefits of potential interventions/exposures/diagnostic tests, and their personal values and expectations. Moreover, clinical expertise is required to integrate evidence with patient values and circumstances.
  • By patient values, we mean the unique preferences, concerns and expectations each patient brings to a clinical encounter and which must be integrated into shared clinical decisions if they are to serve the patient; and by patient circumstances we mean their individual clinical state and the clinical setting.

Why the interest in EBM?

Interest in EBM has grown exponentially since the coining of the term1 in 1992 by a group led by Gordon Guyatt at McMaster University, from 1 Medline citation in 1992 to over 119000 in December 2016. Searching Google and Google Scholar with the terms evidence based medicine retrieves almost 40 million hits and more than 1.5 million hits respectively. We encourage interested readers to review ‘an oral history of EBM’ that was published in 2014 by JAMA and the BMJ and presented by Dr. Richard Smith. This online resource outlines the origins and development of EBM, including discussions with Drs. David Sackett, Brian Haynes and Gordon Guyatt. We also recommend taking a look at the James Lind Library, which provides a more detailed history of the development of ‘fair tests of treatments in health care’ including many of the seminal moments in the history of EBM. As a teaching tip, we use many of the resources provided in the James Lind Library such as the story of James Lind’s 1753 ‘treatise of the scurvy’ and the randomised trial of streptomycin treatment for pulmonary tuberculosis, published in 1948. These are great articles to engage learners and stimulate interest in EBM, while highlighting that EBM isn’t a new concept but instead builds on a solid foundation, the work of countless people worldwide who have been interested in using evidence to support decision making!

Evidence-based practice has become incorporated into many health care disciplines including occupational therapy, physiotherapy, nursing, dentistry, and complementary medicine amongst many others. Indeed, we’ve been told by one publisher that adding evidence-based to the title of a book can increase sales – regardless of whether the book is evidence-based! Similarly, its use has spilled over into many other domains including justice, education, policy making. When we first started working in this area, while we looked for the day when politicians would talk freely about using research evidence to inform their decision making, we did not anticipate it happening so soon or across so many countries! [Trudeau in Canada, Norwegian government]

Because of the recognition that EBM is critical for decision making, professional organizations and training programs for various health care professionals have moved from whether to teach EBM, to how to teach it, resulting in an explosion in the number of courses, workshops and seminars offered in this practice. Similarly, EBM educational interventions for the public, policy makers and health care managers have grown. And, colleagues have extended training on critical appraisal to primary and secondary school students, highlighting that everyone should develop the ability to understand research evidence and use it in their own decision making, thereby enhancing health literacy. The format for teaching EBM to these diverse audiences has also grown showing less focus on didactic sessions and more focus on interactive, case-based discussion, opportunistic teaching, and use of different media including online platforms and social media. Indeed, we hope that this book stimulates interest in sharing content and curricula worldwide, and developing collaborative educational opportunities such as twitter journal clubs and massive online courses.

How do we practise EBM?

The complete practice of EBM comprises five steps, and this book addresses each in turn:

  • Step 1 – converting the need for information (about prevention, diagnosis, prognosis, therapy, causation, etc.) into an answerable question (Ch. 1)
  • Step 2 – tracking down the best evidence with which to answer that question (Ch. 2)
  • Step 3 – critically appraising that evidence for its validity (closeness to the truth), impact (size of the effect), and applicability (usefulness in our clinical practice) (the first halves of Chs 3–7)
  • Step 4 – integrating the critical appraisal with our clinical expertise and with our patient’s unique biology, values and circumstances (the second halves of Chs 3–7)
  • Step 5 – evaluating our effectiveness and efficiency in executing steps 1–4 and seeking ways to improve them both for next time (Ch. 9).

What’s the ‘E’ for EBM?

There is an accumulating body of evidence relating to the impact of EBM on health care professionals from systematic reviews of training in the skills of EBM2 to qualitative research describing the experience of EBM practitioners3. Indeed, since the last edition of this book was published, there has been an explosion in the number of studies evaluating EBM educational interventions targeting primary and secondary school students, undergraduates, postgraduates and practising clinicians. However, these studies of the effect of teaching and practising EBM are challenging to conduct. In many studies, the intervention has been difficult to define. It’s unclear what the appropriate ‘dose’ or ‘formulation’ should be. Some studies use an approach to clinical practice while others use training in one of the discrete ‘microskills’ of EBM such as Medline searching4 or critical appraisal5. Studies have evaluated online, in-person, small group and large group educational interventions.6 Learners have different learning needs and styles and these differences must be reflected in the educational experiences provided.

Just as the intervention has proved difficult to define, the evaluation of whether the intervention has met its goals has been challenging. Effective EBM interventions will produce a wide range of outcomes. Changes in knowledge and skills are relatively easy to detect and demonstrate. Changes in attitudes and behaviours are harder to confirm. Randomised studies of EBM educational interventions have shown that these interventions can change knowledge and attitudes.7 Similarly randomised trials have shown that these interventions can enhance EBM skills.6,8 And, a study has shown that a multi-faceted EBM educational intervention (including access to evidence resources and a seminar series using real clinical scenarios) significantly improved evidence-based practice patterns in a district general hospital.9 Still more challenging is detecting changes in clinical outcomes. Studies of undergraduate and postgraduate educational interventions have shown limited impact on ongoing behaviour or clinical outcomes.6,10 Studies demonstrating better patient survival when practice is evidence-based (and worse when it isn’t) are limited to outcomes research.11,12 We are still waiting to see a trial where access to evidence is withheld from control clinicians. Finally, it is also important to explore impact on all of these various outcomes over time.

Along with the interest in EBM, interest in evaluating EBM and developing evaluation instruments has grown. There are several instruments available for evaluating EBM educational interventions including those that assess attitudes, knowledge and skills. We encourage interested readers to review the systematic review which addresses this topic but note this hasn’t been updated since it was published in 2006 so it should serve as a starting point only.13 For any educational intervention, we encourage teachers and researchers to consider that it is necessary to consider changes in performance and outcomes over time because EBM requires lifelong learning and this is not something that can be measured over the short-term.

By questioning the ‘E’ for EBM, are we asking the right question? It has been recognized that providing evidence from clinical research is a necessary but not sufficient condition for the provision of optimal care. This has created interest in knowledge translation, the scientific study of the methods for closing the knowledge-to-practice gap and the analysis of barriers and facilitators inherent in this process.14 (as a side note here, while in Canada and Australia, we call this knowledge translation, we know other terms are used in other countries including implementation science in the UK and dissemination and implementation in the US).15 Proponents of knowledge translation have identified that changing behaviour is a complex process requiring comprehensive approaches directed towards patients, physicians, managers and policymakers and provision of evidence is but one component. In this edition, we’ll touch briefly on knowledge translation which focuses on evidence-based implementation. This is not the primary focus of the book, which instead targets the practice of individual clinicians, patients and teachers.

How is this resource organized?

The overall package is designed to help practitioners from any health care discipline learn how to practice evidence-based health care. Thus, although the book is written within the perspectives of internal medicine and general practice, the website provides clinical scenarios, questions, searches, critical appraisals, and evidence summaries from other disciplines, permitting readers to apply the strategies and tactics of evidence-based practice to any health discipline.

For those of you who want to become more proficient ‘doers’ of EBM, we’d suggest that you take a look at Chapters 1 through 9. For readers who want to become ‘users’ of EBM, we’d suggest tackling Chapters 1 and 2, focusing on question formulation and matching those questions to the various evidence resources. We have also provided tips on practising EBM in real-time throughout the book. With the inclusion of an ebook, we have been able to incorporate many of the tools/tips/strategies directly in the discussion where they are relevant. We hope this makes it easier for you to use the materials and we encourage you to use the online forum to let us know your thoughts and how this book can be more user-friendly. Finally, for those interested in teaching the practice of EBM, we have dedicated Chapter 7 to this topic.

The chapters and appendices that comprise this book constitute a traditional way of presenting our ideas about EBM. It offers the ‘basic’ version of the model for practising EBM. For those who want more detailed discussion, we’d suggest you review some other resources.16

Additional Resources

Looking for additional resources? Check out the Evidence-Based Medicine Toolbox .

References

  1. Evidence-based Medicine Working Group. Evidence-based medicine. A new approach to teaching the practice of medicine. JAMA 1992;268:2420-5.
  2. Parkes J, Hyde C, Deeks J, Milne R. Teaching critical appraisal skills in health care settings.Cochrane Database of Systematic Reviews 2001, Issue 3. Art. No.: CD001270. DOI: 10.1002/14651858.CD001270
  3. Greenhalgh T, Douglas HR. Experiences of general practitioners and practice nurses of training courses in evidence-based health care: a qualitative study. Br J Gen Pract 1999;49:536-40.
  4. Rosenberg W, Deeks J, Lusher A et al. Improving searching skills and evidence retrieval. J Roy Coll Phys 1998;328:557-63.
  5. Taylor RS, Reeves BC, Ewings PE, Taylor RJ. Critical appraisal skills training for health care professionals: a randomised controlled trial. BMD Med Educ 2004;4:30.
  6. Bradley P, Oterhold C, Herrin J et al. Comparison of directed and seld-directed learning in evidence-based medicine: a randomised controlled trial, Med Educ 2005;39:1027-35.
  7. Johnston J, Schooling CM, Leung GM. A randomised controlled trial of two educational modes for undergraduate evidence-based medicine learning in Asia. BMC Med Educ 2009;9:63.
  8. Shnval K, Berkovits E, Netzer D et al. Evaluating the impact of an evidence-based medicine educational intervention on primary care doctors’ attitudes, knowledge and clinical behaviour: a controlled trial and before and after study. J Eval Clin Pract 2007;13:581-98.
  9. Straus SE, Ball C, Balcombe N, Sheldon, J McAlister FA. Teaching evidence-based medicine skills can change practice in a community hospital. JGIM 2005 April;20(4):340-343.
  10. Kim S, Willett LR, Murphy DJ et al. Impact of an evidence-based medicine curriculum on resident use of electronic resources. JGIM 2008;23:1804-8.
  11. Mitchell J B, Ballard D J, Whisnant J P, Ammering C J, Samsa G P, Matchar D B. What role do neurologists play in determining the costs and outcomes of stroke patients? Stroke 1996; 27: 1937–43.
  12. Wong J H, Findlay J M, Suarez-Almazor M E. Regional performance of carotid endarterectomy appropriateness, outcomes and risk factors for complications. Stroke 1997; 28: 891–8.
  13. Shaneyfelt T, Baum KD, Bell D et al. Instruments for evaluating education in evidence-based practice. JAMA 2006;296:1116-27.
  14. Straus SE, Tetroe J, Graham ID. Defining knowledge translation. CMAJ 2009;181:165-8.
  15. McKibbon KA, Lokker C, Wilczynski NL, Ciliska D, Dobbins M, Davis DA, Haynes RB, Straus SE. A cross-sectional study of the number and frequency of terms used to refer to knowledge translation in a body of health literature in 2006: a Tower of Babel?. Implementation science 2010;5(1):16.
  16. Guyatt G, Rennie D, Meade M, Cook DJ. Ed. Users’ guides to the medical literature. A manual for evidence-based clinical practice. AMA Press: Chicago, 2008