August 2003 Bulletin

Evidence-based practice and the use of practice guidelines

Creating order out of chaos in clinical decision-making

By William C. Watters III, MD

Both the man of science and the man of art live always at the edge of mystery, surrounded by it. Both, as a measure of their creation, have always had to deal with the harmonization of what is new with what is familiar, with the balance between novelty and synthesis, with the struggle to make partial order in total chaos... This cannot be an easy life."

J. Robert Oppenheimer1

Periods of rapid change and transition often lead to confusion and chaos in thinking. These periods present great challenges. This is no truer than in the practice of medicine at the beginning of the 21st Century. Yet the treating clinician – buffeted by evolving issues in practice management, government regulation, ethics and scientific evidence – remains committed and obliged to provide the very best care to his or her patients.

When all is said and done, we are practicing scientists and as such, the basis for the medical decisions we make in patient care is the knowledge base we utilize to exercise clinical judgment. This knowledge base is a result of our medical education, our clinical experience and our ability to assimilate and evaluate the constantly expanding medical literature. The interaction among these three aspects of our knowledge should generate a self-correcting process leading to better patient care. Unfortunately, it often does not. In fact, the practicing clinician today is at an ever-increasing risk of providing patient care that is outdated, ineffective or even dangerous.

With respect to our medical education, it is clear that even the most recent textbooks contain large sections that are out of date. Furthermore, it is fair to say that within five years after completion of a residency, a good deal of the clinical teaching of that residency has changed or been challenged. Thus medical education, long and arduous as it is, is only a starting point for the clinician's knowledge.

Clinical experience also plays a crucial role in clinical decision-making and provides an important adjunct to our scientific knowledge. But psychologists have shown that certain events are given too much weight in decision-making. A randomly bad (or good) outcome, a recent event or an event in early training can influence clinical decision-making disproportionately to their scientific merit and can alter patient care inappropriately.

Scientific reporting: the cornerstone

Thus the contemporary medical literature, as reported at meetings, in medical journals and, increasingly, online, is the cornerstone of good clinical decision-making and good patient care. It is from this evidence that the foundations for the best clinical practice of medicine will continue to evolve and be applied. Yet the sheer volume of this information presents an almost insurmountable problem to the practicing surgeon.

A recently published article indicated that a total of 26,945 papers were published between 1991 and 2000 in the top seven peer-reviewed medical journals.2 Furthermore, as long ago as 1990, there were more than 12,000 citations in that year alone in the orthopaedic literature.3 Compounding the problem is the variability in quality and the often-contradictory results this literature presents to the practicing surgeon.

Clearly no one individual can be aware of all that is being published. How then can the practicing orthopaedic surgeon continue to improve patient care by evaluating this evidence and using the parts of it that are relevant to his or her practice?

Using evidence-based practice

Wright has noted how the best available evidence can be used to make the best clinical decisions.4 He has shown how the medical literature can be sorted through, based on the rigor of each study's design, and assigned a "level of evidence" rating. This allows a means of assessing the quality of the surgical literature and provides the practicing surgeon an opportunity to use only the best data as a basis for his clinical judgments. (Editor's note: See Bulletin, February 2003, p.12, for a detailed Levels of Evidence chart.)

Wright indicated several potential uses for levels of evidence: 1) by journals, to rate the articles being published for their readers; 2) at scientific meetings, to rate the presentations; and 3) by practicing surgeons, to sort through multiple types of conflicting evidence on a particular clinical question. Wright suggested an additional use for levels of evidence in the development of practice guidelines.

Clinical practice guidelines and levels of evidence

Practice guidelines have existed in many different forms for a long time and have often generated conflict and controversy, especially among practicing surgeons. Surgeons often felt "cookbook" medicine was being pushed upon them through guidelines by outside influences such as governmental agencies and even insurance plans.

It is critical to understand what good practice guidelines are intended to be and what they are intended not to be. Good practice guidelines are based on evidence-based practice, defined by Sackett6 as "the integration of best research evidence with clinical expertise and patient values."

Best-practice guidelines represent a logical progression through the diagnosis and treatment of a clinical problem based on the most current evidence that has been evaluated for levels of evidence. The guideline should represent a "middle-of-the-road" approach to the problem that allows for a wide variance in practice style based on the practitioner's clinical expertise and experience. Practice guidelines are not intended to represent a standard of care or an invariant approach to patient treatment. Furthermore, guidelines should not represent some special interest group's standard on how diagnosis and treatment should be administered to achieve anything other than the best possible patient care.

It is difficult to over-emphasize the importance of practice guidelines in contemporary clinical orthopaedics. In the broadest sense, practice guidelines are fundamental to the Clinical Quality Improvement Cycle that drives ever-improving patient care (Figure 1). Practice guidelines represent the evidence-evaluated scientific literature to which performance measures can be applied. These measures are then used to generate outcome evaluations of the treatment paradigms. The performance measures and outcomes point to gaps in the medical evidence and help to produce additional research data that is incorporated into the next generation of guidelines. These guidelines are then further evaluated repeatedly throughout the cycle of Clinical Quality Improvement.

Figure 1: The Clinical Quality Improvement Cycle is an interactive relationship among evidence-based clinicalo practice guidelines (medical literature), performance measures, out-comes from these measures, and research and education leading to new evidence, changes in the guidelines and continuing quality renewal.

Order out of chaos

For the treating surgeon, practice guidelines bring order out of chaos. They allow the surgeon to develop treatment for a specific patient based not only on his experience and personal knowledge, but also on the most up-to-date scientific evidence, recently reviewed and evaluated as to the strength of this evidence.

Through the process of guideline development, experts evaluate and distill the universe of information on a clinical problem down to a usable set of parameters to which the surgeon can apply his own experience and knowledge in managing a patient. Guidelines are not a substitute for continued reading, but rather represent a focus for the surgeon to provide best-practice care for his patients. Practice guidelines also serve as an excellent reference source for the surgeon and can function as an educational tool for the patient.

Practice guidelines: Who does them best?

In his article on the subject, Wong argues that medical societies are the best source of guideline development.5 This is a credible argument and should go far to assuage the fears of "cookbook" medicine among practicing orthopaedic surgeons.

Medical and medical subspecialty societies have the "special knowledge" of clinical medicine and an appreciation of the demands of clinical care. Furthermore, these societies commonly have research, education and quality patient care as stated doctrines. They have the infrastructure to assemble committees of qualified experts from within their ranks and the resources for quality guideline development. Finally, these societies are usually less driven by issues of cost containment and rationing of services than government or business organizations and more driven by issues of best care for the patient.

In the creation of practice guidelines, medical societies realize that evidence-based guidelines are more likely to be clinically effective for the patient and thus most cost-effective in the long run.


  1. Oppenheimer JR. Quoted in Robert Jungk, "Brighter than a Thousand Suns," trans. by James Cleugh (1970).
  2. Rahman M, Pukui T: "A decline in the U.S. share of research articles." New England Journal of Medicine 2002; 347:1211-1212.
  3. Watters, WC: "Evidence-based medicine and the use of clinical guidelines." Presented at the American Academy of Orthopaedic Surgeons Annual Meeting, Dallas, 2002.
  4. Wright JG: "Levels of evidence." AAOS Bulletin 2003: 51:11-12.
  5. Wong DA: "Are specialty society-based treatment guidelines still relevant?" The Spine Journal 2003: 3:91-92.
  6. Sackett DL, Straus SE, Richardson WS, et al: Evidence-based medicine. How to practice and teach EBM, ed.2. London; Churchill Livingstone, 2000.


William C. Watters III, MD, is a member of the AAOS Evidence-Based Practice Committee, a member of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Guidelines Committee for Lumbar Fusion, and co-chairman of the North American Spine Society Guidelines Committee.

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