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FORUM
FORUM - avril 1998

"Evidence-based radiology" in clinical practice, education and research

Harald 0. Stolberg, MD, FRCPC

CAR Forum 1998;42(2):1-2

© 1998 Canadian Association of Radiologists / Association canadienne des radiologistes

Where quality of evidence is lacking, experience, anecdotes, hypothesis or "gut reactions" have masqueraded as evidence. Myth and misinformation are often camouflaged and substitute for or sabotage the use of high quality evidence in decision making.

— M. Watanabe, T. Noseworthy1

The strategic plan of the CAR, published in a previous issue of Forum (vol. 41, no. 6, December 1997), contains the CAR's mission statement and vision. These statements aim to promote the clinical, educational, research and organizational goals of the association and to promote medical imaging in the interest of improved patient care.

In order to do so and to confront the complexity of the practice of diagnostic imaging, it is suggested that we must address the new paradigm of "evidence-based medicine" (EBM) and adapt the requirements of EBM in order to develop and practise evidence-based radiology (EBR).2

This topic was introduced at the 1997 Annual Meeting of the CAR, in the form of the McMaster Symposium on Evidence-Based Radiology.

EBM is the process of systematically finding, appraising and using contemporary research as the basis for clinical decisions.3­5

Developed at McMaster University in Hamilton, Ont., this method of mastering lifelong learning skills and habits has been adopted by many institutions around the world. In radiologic practice, the principles of EBM can form the foundation of a thorough and meaningful consultation. Specifically, EBM offers an opportunity to enhance the interpretive accuracy of film reading and aid the logical choice of a course of action based on criteria of accuracy, patient safety or economics. The practice of EBM involves the integration of individual clinical expertise with the best available external evidence from systematic research, resulting in the conscientious, explicit and judicious use of "current best evidence" in making decisions about individual patients.3 Individual clinical expertise is the proficiency and judgement that individual radiologists acquire with education and practice. It is reflected in improved diagnostic skills and thoughtful interpretation of individual patient's predicaments. "Best clinical evidence" refers to the results of relevant research into the accuracy, precision and applicability of diagnostic tests and the power of prognostic markers.3

Is EBM applicable to everyday radiologic practice in the real world? In fact, this approach corresponds to a radiology consultation performed at the view box for referring physicians and for the benefit of residents. In the course of a radiologic consultation, radiologists are often asked to provide information about the incidence of disease, sensitivity and specificity of individual tests and other relevant data. Anecdotal knowledge forms the traditional base for this transfer of knowledge and is supplemented by "facts" from available texts. However, such texts are not always readily accessible, their use is time-consuming and the information obtained often does not represent "current best evidence." To apply today's standards to radiologic consultation and decision analysis, we must include clinical information, consideration of appropriateness and corroborative imaging procedures as well as morphological analysis, interpretation, probability and other relevant statistical information. With the technology available today, it would be entirely feasible to develop workstations designed not only for "film reading," but these aspects as well.

Such a workstation would provide access to current and previous imaging studies and reports. A state-of-the-art computer would allow one to switch rapidly from online medical records to laboratory and surgical pathology records, to standards and guidelines, and to literature databases such as MEDLINE.6 If this information were readily available, it could be incorporated into radiologic consultations. Such workstations, furthermore, do not depend on the size or location of the hospital or practice, and would even be cost-effective, given the cost of acquiring new textbooks and replacing obsolete ones.

To practice EBR, we must acquire the necessary knowledge and skills. Ideally, EBR should be taught during residency, to assure that radiologists develop comfort with the skills necessary for lifelong learning.

The skills involved in lifelong, problem-based, active, independent and self-directed learning include the abilities to identify, formulate and solve problems and answer questions; to grasp and use basic concepts and principles; and to gather and appraise data rigorously and critically for their validity and usefulness.3,7­10

The criteria for EBM should be applicable to a large and relatively homogeneous population; therefore, in the Canadian context, development of criteria would optimally be performed at the national level. The CAR is in a position to provide leadership to encourage the teaching and practice of EBR and to provide encouragement and support for these developments. The knowledge and skills needed to do so will become a prerequisite not only for teaching and research but for the practice of radiology.

References

  1. Watanabe M, Noseworthy T. Creating a culture of evidence based decision making in health. Ann R Coll Physicians Surg Can 1997;30:137-9.
  2. Evidence Based Medicine Working Group. Evidence based medicine: a new approach to teaching the practice of medicine. JAMA 1992;268:2420-5.
  3. Rosenberg W, Donald A. Evidence based medicine: an approach to clinical problem solving. BMJ 1995;1122-6.
  4. Sackett DL, Haynes RB. On the need for evidence based medicine [editorial]. Evid Based Med 1995;1:5-6.
  5. Sackett DL, Rosenberg W, Gray JAM, Haynes RB, Richardson WS. Evidence based medicine: What it is and what it isn't [editorial]. BMJ 1996;312:71-2.
  6. McKibbon KA, Walker-Dilks CJ. Beyond ACP Journal Club: How to harness MEDLINE for diagnostic problems [editorial]. ACP J Club 1994;121:A10-2.
  7. Jaeschke R, Guyatt GH, Sackett DL, et al. User's guide to the medical literature: 3. How to use an article about a diagnostic test: A. Are the results of the study valid? JAMA 1994;271:389-91.
  8. Jaeschke R, Guyatt GH, Sackett DL, et al. User's guide to the medical literature: 3. How to use an article about a diagnostic test: B. What are the results and will they help me in caring for my patient? JAMA 1994;271:703-7.
  9. Richardson WS, Wilson MC, Nishikawa J, Hayward RSA. The well built clinical question: a key to evidence based decisions [editorial]. ACP J Club 1995;123:
    A12-3.
  10. Sackett DL, Richardson WS, Rosenberg W, Haynes RB. Evidence based medicine: How to practice and teach EBM. New York: Churchill Livingstone; 1997.